source: GTP/trunk/App/Demos/Geom/OgreStuff/include/OgreRenderSystem.h @ 1812

Revision 1812, 55.9 KB checked in by gumbau, 18 years ago (diff)
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1/*
2-----------------------------------------------------------------------------
3This source file is part of OGRE
4    (Object-oriented Graphics Rendering Engine)
5For the latest info, see http://ogre.sourceforge.net/
6
7Copyright (c) 2000-2005 The OGRE Team
8Also see acknowledgements in Readme.html
9
10This program is free software; you can redistribute it and/or modify it under
11the terms of the GNU Lesser General Public License as published by the Free Software
12Foundation; either version 2 of the License, or (at your option) any later
13version.
14
15This program is distributed in the hope that it will be useful, but WITHOUT
16ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
18
19You should have received a copy of the GNU Lesser General Public License along with
20this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21Place - Suite 330, Boston, MA 02111-1307, USA, or go to
22http://www.gnu.org/copyleft/lesser.txt.
23-----------------------------------------------------------------------------
24*/
25#ifndef __RenderSystem_H_
26#define __RenderSystem_H_
27
28// Precompiler options
29#include "OgrePrerequisites.h"
30
31#include "OgreString.h"
32
33#include "OgreTextureUnitState.h"
34#include "OgreCommon.h"
35
36#include "OgreRenderOperation.h"
37#include "OgreRenderSystemCapabilities.h"
38#include "OgreRenderTarget.h"
39#include "OgreRenderTexture.h"
40#include "OgreFrameListener.h"
41#include "OgreConfigOptionMap.h"
42#include "OgreGpuProgram.h"
43#include "OgrePlane.h"
44#include "OgreIteratorWrappers.h"
45
46namespace Ogre
47{
48    typedef std::map< String, RenderTarget * > RenderTargetMap;
49        typedef std::multimap<uchar, RenderTarget * > RenderTargetPriorityMap;
50
51    class TextureManager;
52    /// Enum describing the ways to generate texture coordinates
53    enum TexCoordCalcMethod
54    {
55        /// No calculated texture coordinates
56        TEXCALC_NONE,
57        /// Environment map based on vertex normals
58        TEXCALC_ENVIRONMENT_MAP,
59        /// Environment map based on vertex positions
60        TEXCALC_ENVIRONMENT_MAP_PLANAR,
61        TEXCALC_ENVIRONMENT_MAP_REFLECTION,
62        TEXCALC_ENVIRONMENT_MAP_NORMAL,
63        /// Projective texture
64        TEXCALC_PROJECTIVE_TEXTURE
65    };
66    /// Enum describing the various actions which can be taken onthe stencil buffer
67    enum StencilOperation
68    {
69        /// Leave the stencil buffer unchanged
70        SOP_KEEP,
71        /// Set the stencil value to zero
72        SOP_ZERO,
73        /// Set the stencil value to the reference value
74        SOP_REPLACE,
75        /// Increase the stencil value by 1, clamping at the maximum value
76        SOP_INCREMENT,
77        /// Decrease the stencil value by 1, clamping at 0
78        SOP_DECREMENT,
79        /// Increase the stencil value by 1, wrapping back to 0 when incrementing the maximum value
80        SOP_INCREMENT_WRAP,
81        /// Decrease the stencil value by 1, wrapping when decrementing 0
82        SOP_DECREMENT_WRAP,
83        /// Invert the bits of the stencil buffer
84        SOP_INVERT
85    };
86
87    /** Defines the functionality of a 3D API
88        @remarks
89            The RenderSystem class provides a base interface
90            which abstracts the general functionality of the 3D API
91            e.g. Direct3D or OpenGL. Whilst a few of the general
92            methods have implementations, most of this class is
93            abstract, requiring a subclass based on a specific API
94            to be constructed to provide the full functionality.
95            Note there are 2 levels to the interface - one which
96            will be used often by the caller of the Ogre library,
97            and one which is at a lower level and will be used by the
98            other classes provided by Ogre. These lower level
99            methods are prefixed with '_' to differentiate them.
100            The advanced user of the library may use these lower
101            level methods to access the 3D API at a more fundamental
102            level (dealing direct with render states and rendering
103            primitives), but still benefitting from Ogre's abstraction
104            of exactly which 3D API is in use.
105        @author
106            Steven Streeting
107        @version
108            1.0
109     */
110    class _OgreExport RenderSystem
111    {
112    public:
113        /** Default Constructor.
114        */
115        RenderSystem();
116
117        /** Destructor.
118        */
119        virtual ~RenderSystem();
120
121        /** Returns the name of the rendering system.
122        */
123        virtual const String& getName(void) const = 0;
124
125        /** Returns the details of this API's configuration options
126            @remarks
127                Each render system must be able to inform the world
128                of what options must/can be specified for it's
129                operation.
130            @par
131                These are passed as strings for portability, but
132                grouped into a structure (_ConfigOption) which includes
133                both options and current value.
134            @par
135                Note that the settings returned from this call are
136                affected by the options that have been set so far,
137                since some options are interdependent.
138            @par
139                This routine is called automatically by the default
140                configuration dialogue produced by Root::showConfigDialog
141                or may be used by the caller for custom settings dialogs
142            @returns
143                A 'map' of options, i.e. a list of options which is also
144                indexed by option name.
145         */
146        virtual ConfigOptionMap& getConfigOptions(void) = 0;
147
148        /** Sets an option for this API
149            @remarks
150                Used to confirm the settings (normally chosen by the user) in
151                order to make the renderer able to initialise with the settings as required.
152                This may be video mode, D3D driver, full screen / windowed etc.
153                Called automatically by the default configuration
154                dialog, and by the restoration of saved settings.
155                These settings are stored and only activated when
156                RenderSystem::initialise or RenderSystem::reinitialise
157                are called.
158            @par
159                If using a custom configuration dialog, it is advised that the
160                caller calls RenderSystem::getConfigOptions
161                again, since some options can alter resulting from a selection.
162            @param
163                name The name of the option to alter.
164            @param
165                value The value to set the option to.
166         */
167        virtual void setConfigOption(const String &name, const String &value) = 0;
168
169                /** Create an object for performing hardware occlusion queries.
170                */
171                virtual HardwareOcclusionQuery* createHardwareOcclusionQuery(void) = 0;
172
173                /** Destroy a hardware occlusion query object.
174                */
175                virtual void destroyHardwareOcclusionQuery(HardwareOcclusionQuery *hq);
176
177        /** Validates the options set for the rendering system, returning a message if there are problems.
178            @note
179                If the returned string is empty, there are no problems.
180        */
181        virtual String validateConfigOptions(void) = 0;
182
183        /** Start up the renderer using the settings selected (Or the defaults if none have been selected).
184            @remarks
185                Called by Root::setRenderSystem. Shouldn't really be called
186                directly, although  this can be done if the app wants to.
187            @param
188                autoCreateWindow If true, creates a render window
189                automatically, based on settings chosen so far. This saves
190                an extra call to RenderSystem::createRenderWindow
191                for the main render window.
192            @par
193                If an application has more specific window requirements,
194                however (e.g. a level design app), it should specify false
195                for this parameter and do it manually.
196            @returns
197                A pointer to the automatically created window, if requested, otherwise null.
198        */
199        virtual RenderWindow* initialise(bool autoCreateWindow, const String& windowTitle = "OGRE Render Window");
200
201        /** Restart the renderer (normally following a change in settings).
202        */
203        virtual void reinitialise(void) = 0;
204
205        /** Shutdown the renderer and cleanup resources.
206        */
207        virtual void shutdown(void);
208
209
210        /** Sets the colour & strength of the ambient (global directionless) light in the world.
211        */
212        virtual void setAmbientLight(float r, float g, float b) = 0;
213
214        /** Sets the type of light shading required (default = Gouraud).
215        */
216        virtual void setShadingType(ShadeOptions so) = 0;
217
218        /** Sets whether or not dynamic lighting is enabled.
219            @param
220                enabled If true, dynamic lighting is performed on geometry with normals supplied, geometry without
221                normals will not be displayed. If false, no lighting is applied and all geometry will be full brightness.
222        */
223        virtual void setLightingEnabled(bool enabled) = 0;
224
225        /** Sets whether or not W-buffers are enabled if they are avalible for this renderer.
226                        @param
227                                enabled If true and the renderer supports them W-buffers will be used.  If false
228                                W-buffers will not be used even if avalible.  W-buffers are enabled by default
229                                for 16bit depth buffers and disabled for all other depths.
230        */
231                void setWBufferEnabled(bool enabled);
232
233                /** Returns true if the renderer will try to use W-buffers when avalible.
234                */
235                bool getWBufferEnabled(void) const;
236
237                /** Creates a new rendering window.
238            @remarks
239                This method creates a new rendering window as specified
240                by the paramteters. The rendering system could be
241                responible for only a single window (e.g. in the case
242                of a game), or could be in charge of multiple ones (in the
243                case of a level editor). The option to create the window
244                as a child of another is therefore given.
245                This method will create an appropriate subclass of
246                RenderWindow depending on the API and platform implementation.
247            @par
248                After creation, this window can be retrieved using getRenderTarget().
249            @param
250                name The name of the window. Used in other methods
251                later like setRenderTarget and getRenderWindow.
252            @param
253                width The width of the new window.
254            @param
255                height The height of the new window.
256            @param
257                fullScreen Specify true to make the window full screen
258                without borders, title bar or menu bar.
259            @param
260                miscParams A NameValuePairList describing the other parameters for the new rendering window.
261                                        Options are case sensitive. Unrecognised parameters will be ignored silently.
262                                        These values might be platform dependent, but these are present for all platorms unless
263                                        indicated otherwise:
264                                **
265                                Key: "title"
266                                Description: The title of the window that will appear in the title bar
267                                Values: string
268                                Default: RenderTarget name
269                                **
270                                Key: "colourDepth"
271                                Description: Colour depth of the resulting rendering window; only applies if fullScreen
272                                        is set.
273                                Values: 16 or 32
274                                Default: desktop depth
275                                Notes: [W32 specific]
276                                **
277                                Key: "left"
278                                Description: screen x coordinate from left
279                                Values: positive integers
280                                Default: 'center window on screen'
281                                Notes: Ignored in case of full screen
282                                **
283                                Key: "top"
284                                Description: screen y coordinate from top
285                                Values: positive integers
286                                Default: 'center window on screen'
287                                Notes: Ignored in case of full screen
288                                **
289                                Key: "depthBuffer" [DX9 specific]
290                                Description: Use depth buffer
291                                Values: false or true
292                                Default: true
293                                **
294                                Key: "externalWindowHandle" [API specific]
295                                Description: External window handle, for embedding the OGRE context
296                                Values: positive integer for W32 (HWND handle)
297                                        poslong:posint:poslong (display*:screen:windowHandle) or
298                                        poslong:posint:poslong:poslong (display*:screen:windowHandle:XVisualInfo*) for GLX
299                                Default: 0 (None)
300                                **
301                                Key: "parentWindowHandle" [API specific]
302                                Description: Parent window handle, for embedding the OGRE context
303                                Values: positive integer for W32 (HWND handle)
304                                        poslong:posint:poslong for GLX (display*:screen:windowHandle)
305                                Default: 0 (None)
306                                **
307                                Key: "FSAA"
308                                Description: Full screen antialiasing factor
309                                Values: 0,2,4,6,...
310                                Default: 0
311                                **
312                                Key: "displayFrequency"
313                                Description: Display frequency rate, for fullscreen mode
314                                Values: 60...?
315                                Default: Desktop vsync rate
316                                **
317                                Key: "vsync"
318                                Description: Synchronize buffer swaps to vsync
319                                Values: true, false
320                                Default: 0
321                                **
322                                Key: "border"
323                                Description: The type of window border (in windowed mode)
324                                Values: none, fixed, resize
325                                Default: resize
326                                **
327                                Key: "outerDimensions"
328                                Description: Whether the width/height is expressed as the size of the
329                                outer window, rather than the content area
330                                Values: true, false
331                                Default: false
332                                **
333                                Key: "useNVPerfHUD" [DX9 specific]
334                                Description: Enable the use of nVidia NVPerfHUD
335                                Values: true, false
336                                Default: false
337        */
338                virtual RenderWindow* createRenderWindow(const String &name, unsigned int width, unsigned int height,
339                        bool fullScreen, const NameValuePairList *miscParams = 0) = 0;
340
341                /** Creates and registers a render texture object.
342                        @param name
343                                The name for the new render texture. Note that names must be unique.
344                        @param width
345                                The requested width for the render texture. See Remarks for more info.
346                        @param height
347                                The requested width for the render texture. See Remarks for more info.
348                        @param texType
349                                The type of texture; defaults to TEX_TYPE_2D
350                        @param internalFormat
351                                The internal format of the texture; defaults to PF_X8R8G8B8
352                        @param miscParams This parameter is ignored.
353                        @returns
354                                On succes, a pointer to a new platform-dependernt, RenderTexture-derived
355                                class is returned. On failiure, NULL is returned.
356                        @remarks
357                                Because a render texture is basically a wrapper around a texture object,
358                                the width and height parameters of this method just hint the preferred
359                                size for the texture. Depending on the hardware driver or the underlying
360                                API, these values might change when the texture is created. The same applies
361                                to the internalFormat parameter.
362            @deprecated
363                This method is deprecated, and exists only for backward compatibility. You can create
364                arbitrary rendertextures with the TextureManager::createManual call with usage
365                TU_RENDERTEXTURE.
366                */
367                RenderTexture * createRenderTexture( const String & name, unsigned int width, unsigned int height,
368                        TextureType texType = TEX_TYPE_2D, PixelFormat internalFormat = PF_X8R8G8B8,
369                        const NameValuePairList *miscParams = 0 );
370
371                /**     Create a MultiRenderTarget, which is a render target that renders to multiple RenderTextures
372                        at once. Surfaces can be bound and unbound at will.
373                        This fails if mCapabilities->numMultiRenderTargets() is smaller than 2.
374                */
375                virtual MultiRenderTarget * createMultiRenderTarget(const String & name) = 0;
376
377        /** Destroys a render window */
378        virtual void destroyRenderWindow(const String& name);
379        /** Destroys a render texture */
380        virtual void destroyRenderTexture(const String& name);
381        /** Destroys a render target of any sort */
382        virtual void destroyRenderTarget(const String& name);
383
384        /** Attaches the passed render target to the render system.
385        */
386        virtual void attachRenderTarget( RenderTarget &target );
387        /** Returns a pointer to the render target with the passed name, or NULL if that
388            render target cannot be found.
389        */
390        virtual RenderTarget * getRenderTarget( const String &name );
391        /** Detaches the render target with the passed name from the render system and
392            returns a pointer to it.
393            @note
394                If the render target cannot be found, NULL is returned.
395        */
396        virtual RenderTarget * detachRenderTarget( const String &name );
397
398                /// Iterator over RenderTargets
399                typedef MapIterator<Ogre::RenderTargetMap> RenderTargetIterator;
400
401                /** Returns a specialised MapIterator over all render targets attached to the RenderSystem. */
402                virtual RenderTargetIterator getRenderTargetIterator(void) {
403                        return RenderTargetIterator( mRenderTargets.begin(), mRenderTargets.end() );
404                }
405        /** Returns a description of an error code.
406        */
407        virtual String getErrorDescription(long errorNumber) const = 0;
408
409        /** Defines whether or now fullscreen render windows wait for the vertical blank before flipping buffers.
410            @remarks
411                By default, all rendering windows wait for a vertical blank (when the CRT beam turns off briefly to move
412                from the bottom right of the screen back to the top left) before flipping the screen buffers. This ensures
413                that the image you see on the screen is steady. However it restricts the frame rate to the refresh rate of
414                the monitor, and can slow the frame rate down. You can speed this up by not waiting for the blank, but
415                this has the downside of introducing 'tearing' artefacts where part of the previous frame is still displayed
416                as the buffers are switched. Speed vs quality, you choose.
417            @note
418                Has NO effect on windowed mode render targets. Only affects fullscreen mode.
419            @param
420                enabled If true, the system waits for vertical blanks - quality over speed. If false it doesn't - speed over quality.
421        */
422        void setWaitForVerticalBlank(bool enabled);
423
424        /** Returns true if the system is synchronising frames with the monitor vertical blank.
425        */
426        bool getWaitForVerticalBlank(void) const;
427
428        // ------------------------------------------------------------------------
429        //                     Internal Rendering Access
430        // All methods below here are normally only called by other OGRE classes
431        // They can be called by library user if required
432        // ------------------------------------------------------------------------
433
434
435        /** Tells the rendersystem to use the attached set of lights (and no others)
436        up to the number specified (this allows the same list to be used with different
437        count limits) */
438        virtual void _useLights(const LightList& lights, unsigned short limit) = 0;
439        /** Sets the world transform matrix. */
440        virtual void _setWorldMatrix(const Matrix4 &m) = 0;
441        /** Sets multiple world matrices (vertex blending). */
442        virtual void _setWorldMatrices(const Matrix4* m, unsigned short count);
443        /** Sets the view transform matrix */
444        virtual void _setViewMatrix(const Matrix4 &m) = 0;
445        /** Sets the projection transform matrix */
446        virtual void _setProjectionMatrix(const Matrix4 &m) = 0;
447        /** Utility function for setting all the properties of a texture unit at once.
448            This method is also worth using over the individual texture unit settings because it
449            only sets those settings which are different from the current settings for this
450            unit, thus minimising render state changes.
451        */
452        virtual void _setTextureUnitSettings(size_t texUnit, TextureUnitState& tl);
453        /** Turns off a texture unit. */
454        virtual void _disableTextureUnit(size_t texUnit);
455        /** Disables all texture units from the given unit upwards */
456        virtual void _disableTextureUnitsFrom(size_t texUnit);
457        /** Sets the surface properties to be used for future rendering.
458
459            This method sets the the properties of the surfaces of objects
460            to be rendered after it. In this context these surface properties
461            are the amount of each type of light the object reflects (determining
462            it's colour under different types of light), whether it emits light
463            itself, and how shiny it is. Textures are not dealt with here,
464            see the _setTetxure method for details.
465            This method is used by _setMaterial so does not need to be called
466            direct if that method is being used.
467
468            @param ambient The amount of ambient (sourceless and directionless)
469            light an object reflects. Affected by the colour/amount of ambient light in the scene.
470            @param diffuse The amount of light from directed sources that is
471            reflected (affected by colour/amount of point, directed and spot light sources)
472            @param specular The amount of specular light reflected. This is also
473            affected by directed light sources but represents the colour at the
474            highlights of the object.
475            @param emissive The colour of light emitted from the object. Note that
476            this will make an object seem brighter and not dependent on lights in
477            the scene, but it will not act as a light, so will not illuminate other
478            objects. Use a light attached to the same SceneNode as the object for this purpose.
479            @param shininess A value which only has an effect on specular highlights (so
480            specular must be non-black). The higher this value, the smaller and crisper the
481            specular highlights will be, imitating a more highly polished surface.
482            This value is not constrained to 0.0-1.0, in fact it is likely to
483            be more (10.0 gives a modest sheen to an object).
484            @param tracking A bit field that describes which of the ambient, diffuse, specular
485            and emissive colours follow the vertex colour of the primitive. When a bit in this field is set
486            its ColourValue is ignored. This is a combination of TVC_AMBIENT, TVC_DIFFUSE, TVC_SPECULAR(note that the shininess value is still
487            taken from shininess) and TVC_EMISSIVE. TVC_NONE means that there will be no material property
488            tracking the vertex colours.
489        */
490        virtual void _setSurfaceParams(const ColourValue &ambient,
491            const ColourValue &diffuse, const ColourValue &specular,
492            const ColourValue &emissive, Real shininess,
493            TrackVertexColourType tracking = TVC_NONE) = 0;
494
495                /** Sets whether or not rendering points using OT_POINT_LIST will
496                        render point sprites (textured quads) or plain points.
497                @param enabled True enables point sprites, false returns to normal
498                        point rendering.
499                */     
500                virtual void _setPointSpritesEnabled(bool enabled) = 0;
501
502                /** Sets the size of points and how they are attenuated with distance.
503                @remarks
504                        When performing point rendering or point sprite rendering,
505                        point size can be attenuated with distance. The equation for
506                        doing this is attenuation = 1 / (constant + linear * dist + quadratic * d^2) .
507                @par
508                        For example, to disable distance attenuation (constant screensize)
509                        you would set constant to 1, and linear and quadratic to 0. A
510                        standard perspective attenuation would be 0, 1, 0 respectively.
511                */
512                virtual void _setPointParameters(Real size, bool attenuationEnabled,
513                        Real constant, Real linear, Real quadratic, Real minSize, Real maxSize) = 0;
514
515
516        /**
517          Sets the status of a single texture stage.
518
519          Sets the details of a texture stage, to be used for all primitives
520          rendered afterwards. User processes would
521          not normally call this direct unless rendering
522          primitives themselves - the SubEntity class
523          is designed to manage materials for objects.
524          Note that this method is called by _setMaterial.
525
526          @param unit The index of the texture unit to modify. Multitexturing hardware
527          can support multiple units (see RenderSystemCapabilites::numTextureUnits)
528          @param enabled Boolean to turn the unit on/off
529          @param texname The name of the texture to use - this should have
530              already been loaded with TextureManager::load.
531         */
532        virtual void _setTexture(size_t unit, bool enabled, const String &texname) = 0;
533
534        /**
535          Sets the texture coordinate set to use for a texture unit.
536
537          Meant for use internally - not generally used directly by apps - the Material and TextureUnitState
538          classes let you manage textures far more easily.
539
540          @param unit Texture unit as above
541          @param index The index of the texture coordinate set to use.
542         */
543        virtual void _setTextureCoordSet(size_t unit, size_t index) = 0;
544
545        /**
546          Sets a method for automatically calculating texture coordinates for a stage.
547          Should not be used by apps - for use by Ogre only.
548          @param unit Texture unit as above
549          @param m Calculation method to use
550          @param frustum Optional Frustum param, only used for projective effects
551         */
552        virtual void _setTextureCoordCalculation(size_t unit, TexCoordCalcMethod m,
553            const Frustum* frustum = 0) = 0;
554
555        /** Sets the texture blend modes from a TextureUnitState record.
556            Meant for use internally only - apps should use the Material
557            and TextureUnitState classes.
558            @param unit Texture unit as above
559            @param bm Details of the blending mode
560        */
561        virtual void _setTextureBlendMode(size_t unit, const LayerBlendModeEx& bm) = 0;
562
563        /** Sets the filtering options for a given texture unit.
564        @param unit The texture unit to set the filtering options for
565        @param minFilter The filter used when a texture is reduced in size
566        @param magFilter The filter used when a texture is magnified
567        @param mipFilter The filter used between mipmap levels, FO_NONE disables mipmapping
568        */
569        virtual void _setTextureUnitFiltering(size_t unit, FilterOptions minFilter,
570            FilterOptions magFilter, FilterOptions mipFilter);
571
572        /** Sets a single filter for a given texture unit.
573        @param unit The texture unit to set the filtering options for
574        @param ftype The filter type
575        @param filter The filter to be used
576        */
577        virtual void _setTextureUnitFiltering(size_t unit, FilterType ftype, FilterOptions filter) = 0;
578
579                /** Sets the maximal anisotropy for the specified texture unit.*/
580                virtual void _setTextureLayerAnisotropy(size_t unit, unsigned int maxAnisotropy) = 0;
581
582                /** Sets the texture addressing mode for a texture unit.*/
583        virtual void _setTextureAddressingMode(size_t unit, const TextureUnitState::UVWAddressingMode& uvw) = 0;
584
585                /** Sets the texture border colour for a texture unit.*/
586        virtual void _setTextureBorderColour(size_t unit, const ColourValue& colour) = 0;
587
588        /** Sets the texture coordinate transformation matrix for a texture unit.
589            @param unit Texture unit to affect
590            @param xform The 4x4 matrix
591        */
592        virtual void _setTextureMatrix(size_t unit, const Matrix4& xform) = 0;
593
594        /** Sets the global blending factors for combining subsequent renders with the existing frame contents.
595            The result of the blending operation is:</p>
596            <p align="center">final = (texture * sourceFactor) + (pixel * destFactor)</p>
597            Each of the factors is specified as one of a number of options, as specified in the SceneBlendFactor
598            enumerated type.
599            @param sourceFactor The source factor in the above calculation, i.e. multiplied by the texture colour components.
600            @param destFactor The destination factor in the above calculation, i.e. multiplied by the pixel colour components.
601        */
602        virtual void _setSceneBlending(SceneBlendFactor sourceFactor, SceneBlendFactor destFactor) = 0;
603
604        /** Sets the global alpha rejection approach for future renders.
605            By default images are rendered regardless of texture alpha. This method lets you change that.
606            @param func The comparison function which must pass for a pixel to be written.
607            @param val The value to compare each pixels alpha value to (0-255)
608        */
609        virtual void _setAlphaRejectSettings(CompareFunction func, unsigned char value) = 0;
610        /**
611         * Signifies the beginning of a frame, ie the start of rendering on a single viewport. Will occur
612         * several times per complete frame if multiple viewports exist.
613         */
614        virtual void _beginFrame(void) = 0;
615
616
617        /**
618         * Ends rendering of a frame to the current viewport.
619         */
620        virtual void _endFrame(void) = 0;
621        /**
622          Sets the provided viewport as the active one for future
623          rendering operations. This viewport is aware of it's own
624          camera and render target. Must be implemented by subclass.
625
626          @param target Pointer to the appropriate viewport.
627         */
628        virtual void _setViewport(Viewport *vp) = 0;
629        /** Get the current active viewport for rendering. */
630        virtual Viewport* _getViewport(void);
631
632        /** Sets the culling mode for the render system based on the 'vertex winding'.
633            A typical way for the rendering engine to cull triangles is based on the
634            'vertex winding' of triangles. Vertex winding refers to the direction in
635            which the vertices are passed or indexed to in the rendering operation as viewed
636            from the camera, and will wither be clockwise or anticlockwise (that's 'counterclockwise' for
637            you Americans out there ;) The default is CULL_CLOCKWISE i.e. that only triangles whose vertices
638            are passed/indexed in anticlockwise order are rendered - this is a common approach and is used in 3D studio models
639            for example. You can alter this culling mode if you wish but it is not advised unless you know what you are doing.
640            You may wish to use the CULL_NONE option for mesh data that you cull yourself where the vertex
641            winding is uncertain.
642        */
643        virtual void _setCullingMode(CullingMode mode) = 0;
644
645        virtual CullingMode _getCullingMode(void) const;
646
647        /** Sets the mode of operation for depth buffer tests from this point onwards.
648            Sometimes you may wish to alter the behaviour of the depth buffer to achieve
649            special effects. Because it's unlikely that you'll set these options for an entire frame,
650            but rather use them to tweak settings between rendering objects, this is an internal
651            method (indicated by the '_' prefix) which will be used by a SceneManager implementation
652            rather than directly from the client application.
653            If this method is never called the settings are automatically the same as the default parameters.
654            @param depthTest If true, the depth buffer is tested for each pixel and the frame buffer is only updated
655                if the depth function test succeeds. If false, no test is performed and pixels are always written.
656            @param depthWrite If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds.
657                If false, the depth buffer is left unchanged even if a new pixel is written.
658            @param depthFunction Sets the function required for the depth test.
659        */
660        virtual void _setDepthBufferParams(bool depthTest = true, bool depthWrite = true, CompareFunction depthFunction = CMPF_LESS_EQUAL) = 0;
661
662        /** Sets whether or not the depth buffer check is performed before a pixel write.
663            @param enabled If true, the depth buffer is tested for each pixel and the frame buffer is only updated
664                if the depth function test succeeds. If false, no test is performed and pixels are always written.
665        */
666        virtual void _setDepthBufferCheckEnabled(bool enabled = true) = 0;
667        /** Sets whether or not the depth buffer is updated after a pixel write.
668            @param enabled If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds.
669                If false, the depth buffer is left unchanged even if a new pixel is written.
670        */
671        virtual void _setDepthBufferWriteEnabled(bool enabled = true) = 0;
672        /** Sets the comparison function for the depth buffer check.
673            Advanced use only - allows you to choose the function applied to compare the depth values of
674            new and existing pixels in the depth buffer. Only an issue if the deoth buffer check is enabled
675            (see _setDepthBufferCheckEnabled)
676            @param  func The comparison between the new depth and the existing depth which must return true
677             for the new pixel to be written.
678        */
679        virtual void _setDepthBufferFunction(CompareFunction func = CMPF_LESS_EQUAL) = 0;
680                /** Sets whether or not colour buffer writing is enabled, and for which channels.
681                @remarks
682                        For some advanced effects, you may wish to turn off the writing of certain colour
683                        channels, or even all of the colour channels so that only the depth buffer is updated
684                        in a rendering pass. However, the chances are that you really want to use this option
685                        through the Material class.
686                @param red, green, blue, alpha Whether writing is enabled for each of the 4 colour channels. */
687                virtual void _setColourBufferWriteEnabled(bool red, bool green, bool blue, bool alpha) = 0;
688        /** Sets the depth bias, NB you should use the Material version of this.
689        @remarks
690            When polygons are coplanar, you can get problems with 'depth fighting' where
691            the pixels from the two polys compete for the same screen pixel. This is particularly
692            a problem for decals (polys attached to another surface to represent details such as
693            bulletholes etc.).
694        @par
695            A way to combat this problem is to use a depth bias to adjust the depth buffer value
696            used for the decal such that it is slightly higher than the true value, ensuring that
697            the decal appears on top.
698        @param bias The bias value, should be between 0 and 16.
699        */
700        virtual void _setDepthBias(ushort bias) = 0;
701        /** Sets the fogging mode for future geometry.
702            @param mode Set up the mode of fog as described in the FogMode enum, or set to FOG_NONE to turn off.
703            @param colour The colour of the fog. Either set this to the same as your viewport background colour,
704                or to blend in with a skydome or skybox.
705            @param expDensity The density of the fog in FOG_EXP or FOG_EXP2 mode, as a value between 0 and 1. The default is 1. i.e. completely opaque, lower values can mean
706                that fog never completely obscures the scene.
707            @param linearStart Distance at which linear fog starts to encroach. The distance must be passed
708                as a parametric value between 0 and 1, with 0 being the near clipping plane, and 1 being the far clipping plane. Only applicable if mode is FOG_LINEAR.
709            @param linearEnd Distance at which linear fog becomes completely opaque.The distance must be passed
710                as a parametric value between 0 and 1, with 0 being the near clipping plane, and 1 being the far clipping plane. Only applicable if mode is FOG_LINEAR.
711        */
712        virtual void _setFog(FogMode mode = FOG_NONE, const ColourValue& colour = ColourValue::White, Real expDensity = 1.0, Real linearStart = 0.0, Real linearEnd = 1.0) = 0;
713
714
715        /** The RenderSystem will keep a count of tris rendered, this resets the count. */
716        virtual void _beginGeometryCount(void);
717        /** Reports the number of tris rendered since the last _beginGeometryCount call. */
718        virtual unsigned int _getFaceCount(void) const;
719        /** Reports the number of vertices passed to the renderer since the last _beginGeometryCount call. */
720        virtual unsigned int _getVertexCount(void) const;
721
722        /** Generates a packed data version of the passed in ColourValue suitable for
723            use as with this RenderSystem.
724        @remarks
725            Since different render systems have different colour data formats (eg
726            RGBA for GL, ARGB for D3D) this method allows you to use 1 method for all.
727        @param colour The colour to convert
728        @param pDest Pointer to location to put the result.
729        */
730        virtual void convertColourValue(const ColourValue& colour, uint32* pDest);
731                /** Get the native VertexElementType for a compact 32-bit colour value
732                        for this rendersystem.
733                */
734                virtual VertexElementType getColourVertexElementType(void) const = 0;
735
736        /** Converts a uniform projection matrix to suitable for this render system.
737        @remarks
738            Because different APIs have different requirements (some incompatible) for the
739            projection matrix, this method allows each to implement their own correctly and pass
740            back a generic OGRE matrix for storage in the engine.
741        */
742        virtual void _convertProjectionMatrix(const Matrix4& matrix,
743            Matrix4& dest, bool forGpuProgram = false) = 0;
744
745        /** Builds a perspective projection matrix suitable for this render system.
746        @remarks
747            Because different APIs have different requirements (some incompatible) for the
748            projection matrix, this method allows each to implement their own correctly and pass
749            back a generic OGRE matrix for storage in the engine.
750        */
751        virtual void _makeProjectionMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane,
752            Matrix4& dest, bool forGpuProgram = false) = 0;
753
754        /** Builds a perspective projection matrix for the case when frustum is
755            not centered around camera.
756        @remarks
757            Viewport coordinates are in camera coordinate frame, i.e. camera is
758            at the origin.
759        */
760        virtual void _makeProjectionMatrix(Real left, Real right, Real bottom, Real top,
761            Real nearPlane, Real farPlane, Matrix4& dest, bool forGpuProgram = false) = 0;
762        /** Builds an orthographic projection matrix suitable for this render system.
763        @remarks
764            Because different APIs have different requirements (some incompatible) for the
765            projection matrix, this method allows each to implement their own correctly and pass
766            back a generic OGRE matrix for storage in the engine.
767        */
768        virtual void _makeOrthoMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane,
769            Matrix4& dest, bool forGpuProgram = false) = 0;
770
771                /** Update a perspective projection matrix to use 'oblique depth projection'.
772                @remarks
773                        This method can be used to change the nature of a perspective
774                        transform in order to make the near plane not perpendicular to the
775                        camera view direction, but to be at some different orientation.
776                        This can be useful for performing arbitrary clipping (e.g. to a
777                        reflection plane) which could otherwise only be done using user
778                        clip planes, which are more expensive, and not necessarily supported
779                        on all cards.
780                @param matrix The existing projection matrix. Note that this must be a
781                        perspective transform (not orthographic), and must not have already
782                        been altered by this method. The matrix will be altered in-place.
783                @param plane The plane which is to be used as the clipping plane. This
784                        plane must be in CAMERA (view) space.
785        @param forGpuProgram Is this for use with a Gpu program or fixed-function
786                */
787                virtual void _applyObliqueDepthProjection(Matrix4& matrix, const Plane& plane,
788            bool forGpuProgram) = 0;
789               
790        /** Sets how to rasterise triangles, as points, wireframe or solid polys. */
791        virtual void _setPolygonMode(PolygonMode level) = 0;
792
793        /** Turns stencil buffer checking on or off.
794        @remarks
795            Stencilling (masking off areas of the rendering target based on the stencil
796            buffer) canbe turned on or off using this method. By default, stencilling is
797            disabled.
798        */
799        virtual void setStencilCheckEnabled(bool enabled) = 0;
800        /** Determines if this system supports hardware accelerated stencil buffer.
801        @remarks
802            Note that the lack of this function doesn't mean you can't do stencilling, but
803            the stencilling operations will be provided in software, which will NOT be
804            fast.
805        @par
806            Generally hardware stencils are only supported in 32-bit colour modes, because
807            the stencil buffer shares the memory of the z-buffer, and in most cards the
808            z-buffer has to be the same depth as the colour buffer. This means that in 32-bit
809            mode, 24 bits of the z-buffer are depth and 8 bits are stencil. In 16-bit mode there
810            is no room for a stencil (although some cards support a 15:1 depth:stencil option,
811            this isn't useful for very much) so 8 bits of stencil are provided in software.
812            This can mean that if you use stencilling, your applications may be faster in
813            32-but colour than in 16-bit, which may seem odd to some people.
814        */
815        /*virtual bool hasHardwareStencil(void) = 0;*/
816
817        /** This method allows you to set all the stencil buffer parameters in one call.
818        @remarks
819            The stencil buffer is used to mask out pixels in the render target, allowing
820            you to do effects like mirrors, cut-outs, stencil shadows and more. Each of
821            your batches of rendering is likely to ignore the stencil buffer,
822            update it with new values, or apply it to mask the output of the render.
823            The stencil test is:<PRE>
824            (Reference Value & Mask) CompareFunction (Stencil Buffer Value & Mask)</PRE>
825            The result of this will cause one of 3 actions depending on whether the test fails,
826            succeeds but with the depth buffer check still failing, or succeeds with the
827            depth buffer check passing too.
828        @par
829            Unlike other render states, stencilling is left for the application to turn
830            on and off when it requires. This is because you are likely to want to change
831            parameters between batches of arbitrary objects and control the ordering yourself.
832            In order to batch things this way, you'll want to use OGRE's separate render queue
833            groups (see RenderQueue) and register a RenderQueueListener to get notifications
834            between batches.
835        @par
836            There are individual state change methods for each of the parameters set using
837            this method.
838            Note that the default values in this method represent the defaults at system
839            start up too.
840        @param func The comparison function applied.
841        @param refValue The reference value used in the comparison
842        @param mask The bitmask applied to both the stencil value and the reference value
843            before comparison
844        @param stencilFailOp The action to perform when the stencil check fails
845        @param depthFailOp The action to perform when the stencil check passes, but the
846            depth buffer check still fails
847        @param passOp The action to take when both the stencil and depth check pass.
848        @param twoSidedOperation If set to true, then if you render both back and front faces
849            (you'll have to turn off culling) then these parameters will apply for front faces,
850            and the inverse of them will happen for back faces (keep remains the same).
851        */
852        virtual void setStencilBufferParams(CompareFunction func = CMPF_ALWAYS_PASS,
853            uint32 refValue = 0, uint32 mask = 0xFFFFFFFF,
854            StencilOperation stencilFailOp = SOP_KEEP,
855            StencilOperation depthFailOp = SOP_KEEP,
856            StencilOperation passOp = SOP_KEEP,
857            bool twoSidedOperation = false) = 0;
858
859
860
861                /** Sets the current vertex declaration, ie the source of vertex data. */
862                virtual void setVertexDeclaration(VertexDeclaration* decl) = 0;
863                /** Sets the current vertex buffer binding state. */
864                virtual void setVertexBufferBinding(VertexBufferBinding* binding) = 0;
865
866        /** Sets whether or not normals are to be automatically normalised.
867        @remarks
868            This is useful when, for example, you are scaling SceneNodes such that
869            normals may not be unit-length anymore. Note though that this has an
870            overhead so should not be turn on unless you really need it.
871        @par
872            You should not normally call this direct unless you are rendering
873            world geometry; set it on the Renderable because otherwise it will be
874            overridden by material settings.
875        */
876        virtual void setNormaliseNormals(bool normalise) = 0;
877
878        /**
879          Render something to the active viewport.
880
881          Low-level rendering interface to perform rendering
882          operations. Unlikely to be used directly by client
883          applications, since the SceneManager and various support
884          classes will be responsible for calling this method.
885          Can only be called between _beginScene and _endScene
886
887          @param op A rendering operation instance, which contains
888            details of the operation to be performed.
889         */
890        virtual void _render(const RenderOperation& op);
891
892                /** Gets the capabilities of the render system. */
893                const RenderSystemCapabilities* getCapabilities(void) const { return mCapabilities; }
894
895        /** Binds a given GpuProgram (but not the parameters).
896        @remarks Only one GpuProgram of each type can be bound at once, binding another
897        one will simply replace the exsiting one.
898        */
899        virtual void bindGpuProgram(GpuProgram* prg);
900
901        /** Bind Gpu program parameters.
902        */
903        virtual void bindGpuProgramParameters(GpuProgramType gptype, GpuProgramParametersSharedPtr params) = 0;
904                /** Only binds Gpu program parameters used for passes that have more than one iteration rendering
905        */
906        virtual void bindGpuProgramPassIterationParameters(GpuProgramType gptype) = 0;
907        /** Unbinds GpuPrograms of a given GpuProgramType.
908        @remarks
909            This returns the pipeline to fixed-function processing for this type.
910        */
911        virtual void unbindGpuProgram(GpuProgramType gptype);
912       
913        /** Returns whether or not a Gpu program of the given type is currently bound. */
914        virtual bool isGpuProgramBound(GpuProgramType gptype);
915
916        /** sets the clipping region.
917        */
918        virtual void setClipPlanes(const PlaneList& clipPlanes) = 0;
919
920        /** Utility method for initialising all render targets attached to this rendering system. */
921        virtual void _initRenderTargets(void);
922
923        /** Utility method to notify all render targets that a camera has been removed,
924            incase they were referring to it as their viewer.
925        */
926        virtual void _notifyCameraRemoved(const Camera* cam);
927
928        /** Internal method for updating all render targets attached to this rendering system. */
929        virtual void _updateAllRenderTargets(void);
930
931        /** Set a clipping plane. */
932        virtual void setClipPlane (ushort index, const Plane &p);
933        /** Set a clipping plane. */
934        virtual void setClipPlane (ushort index, Real A, Real B, Real C, Real D) = 0;
935        /** Enable the clipping plane. */
936        virtual void enableClipPlane (ushort index, bool enable) = 0;
937
938        /** Sets whether or not vertex windings set should be inverted; this can be important
939            for rendering reflections. */
940        virtual void setInvertVertexWinding(bool invert);
941        /** Sets the 'scissor region' ie the region of the target in which rendering can take place.
942        @remarks
943            This method allows you to 'mask off' rendering in all but a given rectangular area
944            as identified by the parameters to this method.
945        @note
946            Not all systems support this method. Check the RenderSystemCapabilities for the
947            RSC_SCISSOR_TEST capability to see if it is supported.
948        @param enabled True to enable the scissor test, false to disable it.
949        @param left, top, right, bottom The location of the corners of the rectangle, expressed in
950            <i>pixels</i>.
951        */
952        virtual void setScissorTest(bool enabled, size_t left = 0, size_t top = 0,
953            size_t right = 800, size_t bottom = 600) = 0;
954
955        /** Clears one or more frame buffers on the active render target.
956        @param buffers Combination of one or more elements of FrameBufferType
957            denoting which buffers are to be cleared
958        @param colour The colour to clear the colour buffer with, if enabled
959        @param depth The value to initialise the depth buffer with, if enabled
960        @param stencil The value to initialise the stencil buffer with, if enabled.
961        */
962        virtual void clearFrameBuffer(unsigned int buffers,
963            const ColourValue& colour = ColourValue::Black,
964            Real depth = 1.0f, unsigned short stencil = 0) = 0;
965        /** Returns the horizontal texel offset value required for mapping
966            texel origins to pixel origins in this rendersystem.
967        @remarks
968            Since rendersystems sometimes disagree on the origin of a texel,
969            mapping from texels to pixels can sometimes be problematic to
970            implement generically. This method allows you to retrieve the offset
971            required to map the origin of a texel to the origin of a pixel in
972            the horizontal direction.
973        */
974        virtual Real getHorizontalTexelOffset(void) = 0;
975        /** Returns the vertical texel offset value required for mapping
976        texel origins to pixel origins in this rendersystem.
977        @remarks
978        Since rendersystems sometimes disagree on the origin of a texel,
979        mapping from texels to pixels can sometimes be problematic to
980        implement generically. This method allows you to retrieve the offset
981        required to map the origin of a texel to the origin of a pixel in
982        the vertical direction.
983        */
984        virtual Real getVerticalTexelOffset(void) = 0;
985
986        /** Gets the minimum (closest) depth value to be used when rendering
987            using identity transforms.
988        @remarks
989            When using identity transforms you can manually set the depth
990            of a vertex; however the input values required differ per
991            rendersystem. This method lets you retrieve the correct value.
992        @see Renderable::useIdentityView, Renderable::useIdentityProjection
993        */
994        virtual Real getMinimumDepthInputValue(void) = 0;
995        /** Gets the maximum (farthest) depth value to be used when rendering
996            using identity transforms.
997        @remarks
998            When using identity transforms you can manually set the depth
999            of a vertex; however the input values required differ per
1000            rendersystem. This method lets you retrieve the correct value.
1001        @see Renderable::useIdentityView, Renderable::useIdentityProjection
1002        */
1003        virtual Real getMaximumDepthInputValue(void) = 0;
1004        /** set the current multi pass count value.  This must be set prior to
1005            calling _render() if multiple renderings of the same pass state are
1006            required.
1007        @param count Number of times to render the current state.
1008        */
1009        void setCurrentPassIterationCount(const size_t count) { mCurrentPassIterationCount = count; }
1010
1011                /** Defines a listener on the custom events that this render system
1012                        can raise.
1013                @see RenderSystem::addListener
1014                */
1015                class _OgreExport Listener
1016                {
1017                public:
1018                        Listener() {}
1019                        virtual ~Listener() {}
1020
1021                        /** A rendersystem-specific event occurred.
1022                        @param eventName The name of the event which has occurred
1023                        @param parameters A list of parameters that may belong to this event,
1024                                may be null if there are no parameters
1025                        */
1026                        virtual void eventOccurred(const String& eventName,
1027                                const NameValuePairList* parameters = 0) = 0;
1028                };
1029                /** Adds a listener to the custom events that this render system can raise.
1030                @remarks
1031                        Some render systems have quite specific, internally generated events
1032                        that the application may wish to be notified of. Many applications
1033                        don't have to worry about these events, and can just trust OGRE to
1034                        handle them, but if you want to know, you can add a listener here.
1035                @par
1036                        Events are raised very generically by string name. Perhaps the most
1037                        common example of a render system specific event is the loss and
1038                        restoration of a device in DirectX; which OGRE deals with, but you
1039                        may wish to know when it happens.
1040                @see RenderSystem::getRenderSystemEvents
1041                */
1042                virtual void addListener(Listener* l);
1043                /** Remove a listener to the custom events that this render system can raise.
1044                */
1045                virtual void removeListener(Listener* l);
1046
1047                /** Gets a list of the rendersystem specific events that this rendersystem
1048                        can raise.
1049                @see RenderSystem::addListener
1050                */
1051                virtual const StringVector& getRenderSystemEvents(void) const { return mEventNames; }
1052    protected:
1053
1054               
1055        /** The render targets. */
1056        RenderTargetMap mRenderTargets;
1057                /** The render targets, ordered by priority. */
1058                RenderTargetPriorityMap mPrioritisedRenderTargets;
1059                /** The Active render target. */
1060                RenderTarget * mActiveRenderTarget;
1061        /** The Active GPU programs and gpu program parameters*/
1062        GpuProgramParametersSharedPtr mActiveVertexGpuProgramParameters;
1063        GpuProgramParametersSharedPtr mActiveFragmentGpuProgramParameters;
1064
1065        // Texture manager
1066        // A concrete class of this will be created and
1067        // made available under the TextureManager singleton,
1068        // managed by the RenderSystem
1069        TextureManager* mTextureManager;
1070
1071        /// Used to store the capabilities of the graphics card
1072        RenderSystemCapabilities* mCapabilities;
1073
1074        // Active viewport (dest for future rendering operations)
1075        Viewport* mActiveViewport;
1076
1077        CullingMode mCullingMode;
1078
1079        bool mVSync;
1080                bool mWBuffer;
1081
1082        size_t mFaceCount;
1083        size_t mVertexCount;
1084
1085        /// Saved set of world matrices
1086        Matrix4 mWorldMatrices[256];
1087
1088                /// Saved manual colour blends
1089                ColourValue mManualBlendColours[OGRE_MAX_TEXTURE_LAYERS][2];
1090
1091        bool mInvertVertexWinding;
1092
1093        /// number of times to render the current state
1094        size_t mCurrentPassIterationCount;
1095
1096        /** updates pass iteration rendering state including bound gpu program parameter
1097            pass iteration auto constant entry
1098        @returns True if more iterations are required
1099        */
1100        bool updatePassIterationRenderState(void);
1101
1102                /// List of names of events this rendersystem may raise
1103                StringVector mEventNames;
1104
1105                /// Internal method for firing a rendersystem event
1106                virtual void fireEvent(const String& name, const NameValuePairList* params = 0);
1107
1108                typedef std::list<Listener*> ListenerList;
1109                ListenerList mEventListeners;
1110
1111                typedef std::list<HardwareOcclusionQuery*> HardwareOcclusionQueryList;
1112                HardwareOcclusionQueryList mHwOcclusionQueries;
1113               
1114                bool mVertexProgramBound;
1115                bool mFragmentProgramBound;
1116               
1117
1118
1119    };
1120}
1121
1122#endif
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