source: GTP/trunk/App/Demos/Geom/OgreStuff/include/OgreRenderSystem.h @ 1092

Revision 1092, 52.4 KB checked in by gumbau, 18 years ago (diff)

LodStrips? and LODTrees demos

Line 
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 frame buffers which can be cleared. */
88    enum FrameBufferType {
89        FBT_COLOUR  = 0x1,
90        FBT_DEPTH   = 0x2,
91        FBT_STENCIL = 0x4
92    };
93   
94    /** Defines the functionality of a 3D API
95        @remarks
96            The RenderSystem class provides a base interface
97            which abstracts the general functionality of the 3D API
98            e.g. Direct3D or OpenGL. Whilst a few of the general
99            methods have implementations, most of this class is
100            abstract, requiring a subclass based on a specific API
101            to be constructed to provide the full functionality.
102            Note there are 2 levels to the interface - one which
103            will be used often by the caller of the Ogre library,
104            and one which is at a lower level and will be used by the
105            other classes provided by Ogre. These lower level
106            methods are prefixed with '_' to differentiate them.
107            The advanced user of the library may use these lower
108            level methods to access the 3D API at a more fundamental
109            level (dealing direct with render states and rendering
110            primitives), but still benefitting from Ogre's abstraction
111            of exactly which 3D API is in use.
112        @author
113            Steven Streeting
114        @version
115            1.0
116     */
117    class _OgreExport RenderSystem
118    {
119    public:
120        /** Default Constructor.
121        */
122        RenderSystem();
123
124        /** Destructor.
125        */
126        virtual ~RenderSystem();
127
128        /** Returns the name of the rendering system.
129        */
130        virtual const String& getName(void) const = 0;
131
132        /** Returns the details of this API's configuration options
133            @remarks
134                Each render system must be able to inform the world
135                of what options must/can be specified for it's
136                operation.
137            @par
138                These are passed as strings for portability, but
139                grouped into a structure (_ConfigOption) which includes
140                both options and current value.
141            @par
142                Note that the settings returned from this call are
143                affected by the options that have been set so far,
144                since some options are interdependent.
145            @par
146                This routine is called automatically by the default
147                configuration dialogue produced by Root::showConfigDialog
148                or may be used by the caller for custom settings dialogs
149            @returns
150                A 'map' of options, i.e. a list of options which is also
151                indexed by option name.
152         */
153        virtual ConfigOptionMap& getConfigOptions(void) = 0;
154
155        /** Sets an option for this API
156            @remarks
157                Used to confirm the settings (normally chosen by the user) in
158                order to make the renderer able to initialise with the settings as required.
159                This may be video mode, D3D driver, full screen / windowed etc.
160                Called automatically by the default configuration
161                dialog, and by the restoration of saved settings.
162                These settings are stored and only activated when
163                RenderSystem::initialise or RenderSystem::reinitialise
164                are called.
165            @par
166                If using a custom configuration dialog, it is advised that the
167                caller calls RenderSystem::getConfigOptions
168                again, since some options can alter resulting from a selection.
169            @param
170                name The name of the option to alter.
171            @param
172                value The value to set the option to.
173         */
174        virtual void setConfigOption(const String &name, const String &value) = 0;
175
176                virtual HardwareOcclusionQuery* createHardwareOcclusionQuery() = 0;
177
178        /** Validates the options set for the rendering system, returning a message if there are problems.
179            @note
180                If the returned string is empty, there are no problems.
181        */
182        virtual String validateConfigOptions(void) = 0;
183
184        /** Start up the renderer using the settings selected (Or the defaults if none have been selected).
185            @remarks
186                Called by Root::setRenderSystem. Shouldn't really be called
187                directly, although  this can be done if the app wants to.
188            @param
189                autoCreateWindow If true, creates a render window
190                automatically, based on settings chosen so far. This saves
191                an extra call to RenderSystem::createRenderWindow
192                for the main render window.
193            @par
194                If an application has more specific window requirements,
195                however (e.g. a level design app), it should specify false
196                for this parameter and do it manually.
197            @returns
198                A pointer to the automatically created window, if requested, otherwise null.
199        */
200        virtual RenderWindow* initialise(bool autoCreateWindow, const String& windowTitle = "OGRE Render Window");
201
202        /** Restart the renderer (normally following a change in settings).
203        */
204        virtual void reinitialise(void) = 0;
205
206        /** Shutdown the renderer and cleanup resources.
207        */
208        virtual void shutdown(void);
209
210
211        /** Sets the colour & strength of the ambient (global directionless) light in the world.
212        */
213        virtual void setAmbientLight(float r, float g, float b) = 0;
214
215        /** Sets the type of light shading required (default = Gouraud).
216        */
217        virtual void setShadingType(ShadeOptions so) = 0;
218
219        /** Sets whether or not dynamic lighting is enabled.
220            @param
221                enabled If true, dynamic lighting is performed on geometry with normals supplied, geometry without
222                normals will not be displayed. If false, no lighting is applied and all geometry will be full brightness.
223        */
224        virtual void setLightingEnabled(bool enabled) = 0;
225
226        /** Sets whether or not W-buffers are enabled if they are avalible for this renderer.
227                        @param
228                                enabled If true and the renderer supports them W-buffers will be used.  If false
229                                W-buffers will not be used even if avalible.  W-buffers are enabled by default
230                                for 16bit depth buffers and disabled for all other depths.
231        */
232                void setWBufferEnabled(bool enabled);
233
234                /** Returns true if the renderer will try to use W-buffers when avalible.
235                */
236                bool getWBufferEnabled(void) const;
237
238                /** Creates a new rendering window.
239            @remarks
240                This method creates a new rendering window as specified
241                by the paramteters. The rendering system could be
242                responible for only a single window (e.g. in the case
243                of a game), or could be in charge of multiple ones (in the
244                case of a level editor). The option to create the window
245                as a child of another is therefore given.
246                This method will create an appropriate subclass of
247                RenderWindow depending on the API and platform implementation.
248            @par
249                After creation, this window can be retrieved using getRenderTarget().
250            @param
251                name The name of the window. Used in other methods
252                later like setRenderTarget and getRenderWindow.
253            @param
254                width The width of the new window.
255            @param
256                height The height of the new window.
257            @param
258                fullScreen Specify true to make the window full screen
259                without borders, title bar or menu bar.
260            @param
261                miscParams A NameValuePairList describing the other parameters for the new rendering window.
262                                        Options are case sensitive. Unrecognised parameters will be ignored silently.
263                                        These values might be platform dependent, but these are present for all platorms unless
264                                        indicated otherwise:
265                                **
266                                Key: "title"
267                                Description: The title of the window that will appear in the title bar
268                                Values: string
269                                Default: RenderTarget name
270                                **
271                                Key: "colourDepth"
272                                Description: Colour depth of the resulting rendering window; only applies if fullScreen
273                                        is set.
274                                Values: 16 or 32
275                                Default: desktop depth
276                                Notes: [W32 specific]
277                                **
278                                Key: "left"
279                                Description: screen x coordinate from left
280                                Values: positive integers
281                                Default: 'center window on screen'
282                                Notes: Ignored in case of full screen
283                                **
284                                Key: "top"
285                                Description: screen y coordinate from top
286                                Values: positive integers
287                                Default: 'center window on screen'
288                                Notes: Ignored in case of full screen
289                                **
290                                Key: "depthBuffer" [DX9 specific]
291                                Description: Use depth buffer
292                                Values: false or true
293                                Default: true
294                                **
295                                Key: "externalWindowHandle" [API specific]
296                                Description: External window handle, for embedding the OGRE context
297                                Values: positive integer for W32 (HWND handle)
298                                        poslong:posint:poslong (display*:screen:windowHandle) or
299                                        poslong:posint:poslong:poslong (display*:screen:windowHandle:XVisualInfo*) for GLX
300                                Default: 0 (None)
301                                **
302                                Key: "parentWindowHandle" [API specific]
303                                Description: Parent window handle, for embedding the OGRE context
304                                Values: positive integer for W32 (HWND handle)
305                                        poslong:posint:poslong for GLX (display*:screen:windowHandle)
306                                Default: 0 (None)
307                                **
308                                Key: "FSAA"
309                                Description: Full screen antialiasing factor
310                                Values: 0,2,4,6,...
311                                Default: 0
312                                **
313                                Key: "displayFrequency"
314                                Description: Display frequency rate, for fullscreen mode
315                                Values: 60...?
316                                Default: Desktop vsync rate
317                                **
318                                Key: "vsync"
319                                Description: Synchronize buffer swaps to vsync
320                                Values: true, false
321                                Default: 0
322                                **
323                                Key: "border"
324                                Description: The type of window border (in windowed mode)
325                                Values: none, fixed, resize
326                                Default: resize
327                                **
328                                Key: "outerDimensions"
329                                Description: Whether the width/height is expressed as the size of the
330                                outer window, rather than the content area
331                                Values: true, false
332                                Default: false
333        */
334                virtual RenderWindow* createRenderWindow(const String &name, unsigned int width, unsigned int height,
335                        bool fullScreen, const NameValuePairList *miscParams = 0) = 0;
336
337                /** Creates and registers a render texture object.
338                        @param name
339                                The name for the new render texture. Note that names must be unique.
340                        @param width
341                                The requested width for the render texture. See Remarks for more info.
342                        @param height
343                                The requested width for the render texture. See Remarks for more info.
344                        @param texType
345                                The type of texture; defaults to TEX_TYPE_2D
346                        @param internalFormat
347                                The internal format of the texture; defaults to PF_X8R8G8B8
348                        @param miscParams A NameValuePairList describing the other parameters for the new rendering window.
349                                        Unrecognised parameters will be ignored silently.
350                                        These values might be platform dependent, but these are present for all platorms unless
351                                        indicated otherwise:
352                                **
353                                Key: "FSAA"
354                                Description: Full screen antialiasing factor
355                                Values: 0,2,4,6,...
356                                Default: 0
357                                **
358                                Key: "depth"
359                                Description: Depth in case of render-to-texture TEX_3D
360                                Values: positive integers
361                        @returns
362                                On succes, a pointer to a new platform-dependernt, RenderTexture-derived
363                                class is returned. On failiure, NULL is returned.
364                        @remarks
365                                Because a render texture is basically a wrapper around a texture object,
366                                the width and height parameters of this method just hint the preferred
367                                size for the texture. Depending on the hardware driver or the underlying
368                                API, these values might change when the texture is created. The same applies
369                                to the internalFormat parameter.
370                */
371                virtual RenderTexture * createRenderTexture( const String & name, unsigned int width, unsigned int height,
372                        TextureType texType = TEX_TYPE_2D, PixelFormat internalFormat = PF_X8R8G8B8,
373                        const NameValuePairList *miscParams = 0 ) = 0;
374
375        /** Destroys a render window */
376        virtual void destroyRenderWindow(const String& name);
377        /** Destroys a render texture */
378        virtual void destroyRenderTexture(const String& name);
379        /** Destroys a render target of any sort */
380        virtual void destroyRenderTarget(const String& name);
381
382        /** Attaches the passed render target to the render system.
383        */
384        virtual void attachRenderTarget( RenderTarget &target );
385        /** Returns a pointer to the render target with the passed name, or NULL if that
386            render target cannot be found.
387        */
388        virtual RenderTarget * getRenderTarget( const String &name );
389        /** Detaches the render target with the passed name from the render system and
390            returns a pointer to it.
391            @note
392                If the render target cannot be found, NULL is returned.
393        */
394        virtual RenderTarget * detachRenderTarget( const String &name );
395
396                /// Iterator over RenderTargets
397                typedef MapIterator<Ogre::RenderTargetMap> RenderTargetIterator;
398
399                /** Returns a specialised MapIterator over all render targets attached to the RenderSystem. */
400                virtual RenderTargetIterator getRenderTargetIterator(void) {
401                        return RenderTargetIterator( mRenderTargets.begin(), mRenderTargets.end() );
402                }
403        /** Returns a description of an error code.
404        */
405        virtual String getErrorDescription(long errorNumber) const = 0;
406
407        /** Defines whether or now fullscreen render windows wait for the vertical blank before flipping buffers.
408            @remarks
409                By default, all rendering windows wait for a vertical blank (when the CRT beam turns off briefly to move
410                from the bottom right of the screen back to the top left) before flipping the screen buffers. This ensures
411                that the image you see on the screen is steady. However it restricts the frame rate to the refresh rate of
412                the monitor, and can slow the frame rate down. You can speed this up by not waiting for the blank, but
413                this has the downside of introducing 'tearing' artefacts where part of the previous frame is still displayed
414                as the buffers are switched. Speed vs quality, you choose.
415            @note
416                Has NO effect on windowed mode render targets. Only affects fullscreen mode.
417            @param
418                enabled If true, the system waits for vertical blanks - quality over speed. If false it doesn't - speed over quality.
419        */
420        void setWaitForVerticalBlank(bool enabled);
421
422        /** Returns true if the system is synchronising frames with the monitor vertical blank.
423        */
424        bool getWaitForVerticalBlank(void) const;
425
426        // ------------------------------------------------------------------------
427        //                     Internal Rendering Access
428        // All methods below here are normally only called by other OGRE classes
429        // They can be called by library user if required
430        // ------------------------------------------------------------------------
431
432
433        /** Tells the rendersystem to use the attached set of lights (and no others)
434        up to the number specified (this allows the same list to be used with different
435        count limits) */
436        virtual void _useLights(const LightList& lights, unsigned short limit) = 0;
437        /** Sets the world transform matrix. */
438        virtual void _setWorldMatrix(const Matrix4 &m) = 0;
439        /** Sets multiple world matrices (vertex blending). */
440        virtual void _setWorldMatrices(const Matrix4* m, unsigned short count);
441        /** Sets the view transform matrix */
442        virtual void _setViewMatrix(const Matrix4 &m) = 0;
443        /** Sets the projection transform matrix */
444        virtual void _setProjectionMatrix(const Matrix4 &m) = 0;
445        /** Utility function for setting all the properties of a texture unit at once.
446            This method is also worth using over the individual texture unit settings because it
447            only sets those settings which are different from the current settings for this
448            unit, thus minimising render state changes.
449        */
450        virtual void _setTextureUnitSettings(size_t texUnit, TextureUnitState& tl);
451        /** Turns off a texture unit. */
452        virtual void _disableTextureUnit(size_t texUnit);
453        /** Disables all texture units from the given unit upwards */
454        virtual void _disableTextureUnitsFrom(size_t texUnit);
455        /** Sets the surface properties to be used for future rendering.
456
457            This method sets the the properties of the surfaces of objects
458            to be rendered after it. In this context these surface properties
459            are the amount of each type of light the object reflects (determining
460            it's colour under different types of light), whether it emits light
461            itself, and how shiny it is. Textures are not dealt with here,
462            see the _setTetxure method for details.
463            This method is used by _setMaterial so does not need to be called
464            direct if that method is being used.
465
466            @param ambient The amount of ambient (sourceless and directionless)
467            light an object reflects. Affected by the colour/amount of ambient light in the scene.
468            @param diffuse The amount of light from directed sources that is
469            reflected (affected by colour/amount of point, directed and spot light sources)
470            @param specular The amount of specular light reflected. This is also
471            affected by directed light sources but represents the colour at the
472            highlights of the object.
473            @param emissive The colour of light emitted from the object. Note that
474            this will make an object seem brighter and not dependent on lights in
475            the scene, but it will not act as a light, so will not illuminate other
476            objects. Use a light attached to the same SceneNode as the object for this purpose.
477            @param shininess A value which only has an effect on specular highlights (so
478            specular must be non-black). The higher this value, the smaller and crisper the
479            specular highlights will be, imitating a more highly polished surface.
480            This value is not constrained to 0.0-1.0, in fact it is likely to
481            be more (10.0 gives a modest sheen to an object).
482            @param tracking A bit field that describes which of the ambient, diffuse, specular
483            and emissive colours follow the vertex colour of the primitive. When a bit in this field is set
484            its ColourValue is ignored. This is a combination of TVC_AMBIENT, TVC_DIFFUSE, TVC_SPECULAR(note that the shininess value is still
485            taken from shininess) and TVC_EMISSIVE. TVC_NONE means that there will be no material property
486            tracking the vertex colours.
487        */
488        virtual void _setSurfaceParams(const ColourValue &ambient,
489            const ColourValue &diffuse, const ColourValue &specular,
490            const ColourValue &emissive, Real shininess,
491            TrackVertexColourType tracking = TVC_NONE) = 0;
492        /**
493          Sets the status of a single texture stage.
494
495          Sets the details of a texture stage, to be used for all primitives
496          rendered afterwards. User processes would
497          not normally call this direct unless rendering
498          primitives themselves - the SubEntity class
499          is designed to manage materials for objects.
500          Note that this method is called by _setMaterial.
501
502          @param unit The index of the texture unit to modify. Multitexturing hardware
503          can support multiple units (see RenderSystemCapabilites::numTextureUnits)
504          @param enabled Boolean to turn the unit on/off
505          @param texname The name of the texture to use - this should have
506              already been loaded with TextureManager::load.
507         */
508        virtual void _setTexture(size_t unit, bool enabled, const String &texname) = 0;
509
510        /**
511          Sets the texture coordinate set to use for a texture unit.
512
513          Meant for use internally - not generally used directly by apps - the Material and TextureUnitState
514          classes let you manage textures far more easily.
515
516          @param unit Texture unit as above
517          @param index The index of the texture coordinate set to use.
518         */
519        virtual void _setTextureCoordSet(size_t unit, size_t index) = 0;
520
521        /**
522          Sets a method for automatically calculating texture coordinates for a stage.
523          Should not be used by apps - for use by Ogre only.
524          @param unit Texture unit as above
525          @param m Calculation method to use
526          @param frustum Optional Frustum param, only used for projective effects
527         */
528        virtual void _setTextureCoordCalculation(size_t unit, TexCoordCalcMethod m,
529            const Frustum* frustum = 0) = 0;
530
531        /** Sets the texture blend modes from a TextureUnitState record.
532            Meant for use internally only - apps should use the Material
533            and TextureUnitState classes.
534            @param unit Texture unit as above
535            @param bm Details of the blending mode
536        */
537        virtual void _setTextureBlendMode(size_t unit, const LayerBlendModeEx& bm) = 0;
538
539        /** Sets the filtering options for a given texture unit.
540        @param unit The texture unit to set the filtering options for
541        @param minFilter The filter used when a texture is reduced in size
542        @param magFilter The filter used when a texture is magnified
543        @param mipFilter The filter used between mipmap levels, FO_NONE disables mipmapping
544        */
545        virtual void _setTextureUnitFiltering(size_t unit, FilterOptions minFilter,
546            FilterOptions magFilter, FilterOptions mipFilter);
547
548        /** Sets a single filter for a given texture unit.
549        @param unit The texture unit to set the filtering options for
550        @param ftype The filter type
551        @param filter The filter to be used
552        */
553        virtual void _setTextureUnitFiltering(size_t unit, FilterType ftype, FilterOptions filter) = 0;
554
555                /** Sets the maximal anisotropy for the specified texture unit.*/
556                virtual void _setTextureLayerAnisotropy(size_t unit, unsigned int maxAnisotropy) = 0;
557
558                /** Sets the texture addressing mode for a texture unit.*/
559        virtual void _setTextureAddressingMode(size_t unit, TextureUnitState::TextureAddressingMode tam) = 0;
560
561        /** Sets the texture coordinate transformation matrix for a texture unit.
562            @param unit Texture unit to affect
563            @param xform The 4x4 matrix
564        */
565        virtual void _setTextureMatrix(size_t unit, const Matrix4& xform) = 0;
566
567        /** Sets the global blending factors for combining subsequent renders with the existing frame contents.
568            The result of the blending operation is:</p>
569            <p align="center">final = (texture * sourceFactor) + (pixel * destFactor)</p>
570            Each of the factors is specified as one of a number of options, as specified in the SceneBlendFactor
571            enumerated type.
572            @param sourceFactor The source factor in the above calculation, i.e. multiplied by the texture colour components.
573            @param destFactor The destination factor in the above calculation, i.e. multiplied by the pixel colour components.
574        */
575        virtual void _setSceneBlending(SceneBlendFactor sourceFactor, SceneBlendFactor destFactor) = 0;
576
577        /** Sets the global alpha rejection approach for future renders.
578            By default images are rendered regardless of texture alpha. This method lets you change that.
579            @param func The comparison function which must pass for a pixel to be written.
580            @param val The value to compare each pixels alpha value to (0-255)
581        */
582        virtual void _setAlphaRejectSettings(CompareFunction func, unsigned char value) = 0;
583        /**
584         * Signifies the beginning of a frame, ie the start of rendering on a single viewport. Will occur
585         * several times per complete frame if multiple viewports exist.
586         */
587        virtual void _beginFrame(void) = 0;
588
589
590        /**
591         * Ends rendering of a frame to the current viewport.
592         */
593        virtual void _endFrame(void) = 0;
594        /**
595          Sets the provided viewport as the active one for future
596          rendering operations. This viewport is aware of it's own
597          camera and render target. Must be implemented by subclass.
598
599          @param target Pointer to the appropriate viewport.
600         */
601        virtual void _setViewport(Viewport *vp) = 0;
602        /** Get the current active viewport for rendering. */
603        virtual Viewport* _getViewport(void);
604
605        /** Sets the culling mode for the render system based on the 'vertex winding'.
606            A typical way for the rendering engine to cull triangles is based on the
607            'vertex winding' of triangles. Vertex winding refers to the direction in
608            which the vertices are passed or indexed to in the rendering operation as viewed
609            from the camera, and will wither be clockwise or anticlockwise (that's 'counterclockwise' for
610            you Americans out there ;) The default is CULL_CLOCKWISE i.e. that only triangles whose vertices
611            are passed/indexed in anticlockwise order are rendered - this is a common approach and is used in 3D studio models
612            for example. You can alter this culling mode if you wish but it is not advised unless you know what you are doing.
613            You may wish to use the CULL_NONE option for mesh data that you cull yourself where the vertex
614            winding is uncertain.
615        */
616        virtual void _setCullingMode(CullingMode mode) = 0;
617
618        virtual CullingMode _getCullingMode(void) const;
619
620        /** Sets the mode of operation for depth buffer tests from this point onwards.
621            Sometimes you may wish to alter the behaviour of the depth buffer to achieve
622            special effects. Because it's unlikely that you'll set these options for an entire frame,
623            but rather use them to tweak settings between rendering objects, this is an internal
624            method (indicated by the '_' prefix) which will be used by a SceneManager implementation
625            rather than directly from the client application.
626            If this method is never called the settings are automatically the same as the default parameters.
627            @param depthTest If true, the depth buffer is tested for each pixel and the frame buffer is only updated
628                if the depth function test succeeds. If false, no test is performed and pixels are always written.
629            @param depthWrite If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds.
630                If false, the depth buffer is left unchanged even if a new pixel is written.
631            @param depthFunction Sets the function required for the depth test.
632        */
633        virtual void _setDepthBufferParams(bool depthTest = true, bool depthWrite = true, CompareFunction depthFunction = CMPF_LESS_EQUAL) = 0;
634
635        /** Sets whether or not the depth buffer check is performed before a pixel write.
636            @param enabled If true, the depth buffer is tested for each pixel and the frame buffer is only updated
637                if the depth function test succeeds. If false, no test is performed and pixels are always written.
638        */
639        virtual void _setDepthBufferCheckEnabled(bool enabled = true) = 0;
640        /** Sets whether or not the depth buffer is updated after a pixel write.
641            @param enabled If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds.
642                If false, the depth buffer is left unchanged even if a new pixel is written.
643        */
644        virtual void _setDepthBufferWriteEnabled(bool enabled = true) = 0;
645        /** Sets the comparison function for the depth buffer check.
646            Advanced use only - allows you to choose the function applied to compare the depth values of
647            new and existing pixels in the depth buffer. Only an issue if the deoth buffer check is enabled
648            (see _setDepthBufferCheckEnabled)
649            @param  func The comparison between the new depth and the existing depth which must return true
650             for the new pixel to be written.
651        */
652        virtual void _setDepthBufferFunction(CompareFunction func = CMPF_LESS_EQUAL) = 0;
653                /** Sets whether or not colour buffer writing is enabled, and for which channels.
654                @remarks
655                        For some advanced effects, you may wish to turn off the writing of certain colour
656                        channels, or even all of the colour channels so that only the depth buffer is updated
657                        in a rendering pass. However, the chances are that you really want to use this option
658                        through the Material class.
659                @param red, green, blue, alpha Whether writing is enabled for each of the 4 colour channels. */
660                virtual void _setColourBufferWriteEnabled(bool red, bool green, bool blue, bool alpha) = 0;
661        /** Sets the depth bias, NB you should use the Material version of this.
662        @remarks
663            When polygons are coplanar, you can get problems with 'depth fighting' where
664            the pixels from the two polys compete for the same screen pixel. This is particularly
665            a problem for decals (polys attached to another surface to represent details such as
666            bulletholes etc.).
667        @par
668            A way to combat this problem is to use a depth bias to adjust the depth buffer value
669            used for the decal such that it is slightly higher than the true value, ensuring that
670            the decal appears on top.
671        @param bias The bias value, should be between 0 and 16.
672        */
673        virtual void _setDepthBias(ushort bias) = 0;
674        /** Sets the fogging mode for future geometry.
675            @param mode Set up the mode of fog as described in the FogMode enum, or set to FOG_NONE to turn off.
676            @param colour The colour of the fog. Either set this to the same as your viewport background colour,
677                or to blend in with a skydome or skybox.
678            @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
679                that fog never completely obscures the scene.
680            @param linearStart Distance at which linear fog starts to encroach. The distance must be passed
681                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.
682            @param linearEnd Distance at which linear fog becomes completely opaque.The distance must be passed
683                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.
684        */
685        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;
686
687
688        /** The RenderSystem will keep a count of tris rendered, this resets the count. */
689        virtual void _beginGeometryCount(void);
690        /** Reports the number of tris rendered since the last _beginGeometryCount call. */
691        virtual unsigned int _getFaceCount(void) const;
692        /** Reports the number of vertices passed to the renderer since the last _beginGeometryCount call. */
693        virtual unsigned int _getVertexCount(void) const;
694
695        /** Generates a packed data version of the passed in ColourValue suitable for
696            use as with this RenderSystem.
697        @remarks
698            Since different render systems have different colour data formats (eg
699            RGBA for GL, ARGB for D3D) this method allows you to use 1 method for all.
700        @param colour The colour to convert
701        @param pDest Pointer to location to put the result.
702        */
703        virtual void convertColourValue(const ColourValue& colour, uint32* pDest) = 0;
704
705        /** Builds a perspective projection matrix suitable for this render system.
706        @remarks
707            Because different APIs have different requirements (some incompatible) for the
708            projection matrix, this method allows each to implement their own correctly and pass
709            back a generic OGRE matrix for storage in the engine.
710        */
711        virtual void _makeProjectionMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane,
712            Matrix4& dest, bool forGpuProgram = false) = 0;
713
714        /** Builds a perspective projection matrix for the case when frustum is
715            not centered around camera.
716        @remarks
717            Viewport coordinates are in camera coordinate frame, i.e. camera is
718            at the origin.
719        */
720        virtual void _makeProjectionMatrix(Real left, Real right, Real bottom, Real top,
721            Real nearPlane, Real farPlane, Matrix4& dest, bool forGpuProgram = false) = 0;
722        /** Builds an orthographic projection matrix suitable for this render system.
723        @remarks
724            Because different APIs have different requirements (some incompatible) for the
725            projection matrix, this method allows each to implement their own correctly and pass
726            back a generic OGRE matrix for storage in the engine.
727        */
728        virtual void _makeOrthoMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane,
729            Matrix4& dest, bool forGpuProgram = false) = 0;
730
731                /** Update a perspective projection matrix to use 'oblique depth projection'.
732                @remarks
733                        This method can be used to change the nature of a perspective
734                        transform in order to make the near plane not perpendicular to the
735                        camera view direction, but to be at some different orientation.
736                        This can be useful for performing arbitrary clipping (e.g. to a
737                        reflection plane) which could otherwise only be done using user
738                        clip planes, which are more expensive, and not necessarily supported
739                        on all cards.
740                @param matrix The existing projection matrix. Note that this must be a
741                        perspective transform (not orthographic), and must not have already
742                        been altered by this method. The matrix will be altered in-place.
743                @param plane The plane which is to be used as the clipping plane. This
744                        plane must be in CAMERA (view) space.
745        @param forGpuProgram Is this for use with a Gpu program or fixed-function
746                */
747                virtual void _applyObliqueDepthProjection(Matrix4& matrix, const Plane& plane,
748            bool forGpuProgram) = 0;
749               
750        /** Sets how to rasterise triangles, as points, wireframe or solid polys. */
751        virtual void _setRasterisationMode(SceneDetailLevel level) = 0;
752
753        /** Turns stencil buffer checking on or off.
754        @remarks
755            Stencilling (masking off areas of the rendering target based on the stencil
756            buffer) canbe turned on or off using this method. By default, stencilling is
757            disabled.
758        */
759        virtual void setStencilCheckEnabled(bool enabled) = 0;
760        /** Determines if this system supports hardware accelerated stencil buffer.
761        @remarks
762            Note that the lack of this function doesn't mean you can't do stencilling, but
763            the stencilling operations will be provided in software, which will NOT be
764            fast.
765        @par
766            Generally hardware stencils are only supported in 32-bit colour modes, because
767            the stencil buffer shares the memory of the z-buffer, and in most cards the
768            z-buffer has to be the same depth as the colour buffer. This means that in 32-bit
769            mode, 24 bits of the z-buffer are depth and 8 bits are stencil. In 16-bit mode there
770            is no room for a stencil (although some cards support a 15:1 depth:stencil option,
771            this isn't useful for very much) so 8 bits of stencil are provided in software.
772            This can mean that if you use stencilling, your applications may be faster in
773            32-but colour than in 16-bit, which may seem odd to some people.
774        */
775        /*virtual bool hasHardwareStencil(void) = 0;*/
776
777        /** This method allows you to set all the stencil buffer parameters in one call.
778        @remarks
779            The stencil buffer is used to mask out pixels in the render target, allowing
780            you to do effects like mirrors, cut-outs, stencil shadows and more. Each of
781            your batches of rendering is likely to ignore the stencil buffer,
782            update it with new values, or apply it to mask the output of the render.
783            The stencil test is:<PRE>
784            (Reference Value & Mask) CompareFunction (Stencil Buffer Value & Mask)</PRE>
785            The result of this will cause one of 3 actions depending on whether the test fails,
786            succeeds but with the depth buffer check still failing, or succeeds with the
787            depth buffer check passing too.
788        @par
789            Unlike other render states, stencilling is left for the application to turn
790            on and off when it requires. This is because you are likely to want to change
791            parameters between batches of arbitrary objects and control the ordering yourself.
792            In order to batch things this way, you'll want to use OGRE's separate render queue
793            groups (see RenderQueue) and register a RenderQueueListener to get notifications
794            between batches.
795        @par
796            There are individual state change methods for each of the parameters set using
797            this method.
798            Note that the default values in this method represent the defaults at system
799            start up too.
800        @param func The comparison function applied.
801        @param refValue The reference value used in the comparison
802        @param mask The bitmask applied to both the stencil value and the reference value
803            before comparison
804        @param stencilFailOp The action to perform when the stencil check fails
805        @param depthFailOp The action to perform when the stencil check passes, but the
806            depth buffer check still fails
807        @param passOp The action to take when both the stencil and depth check pass.
808        @param twoSidedOperation If set to true, then if you render both back and front faces
809            (you'll have to turn off culling) then these parameters will apply for front faces,
810            and the inverse of them will happen for back faces (keep remains the same).
811        */
812        virtual void setStencilBufferParams(CompareFunction func = CMPF_ALWAYS_PASS,
813            uint32 refValue = 0, uint32 mask = 0xFFFFFFFF,
814            StencilOperation stencilFailOp = SOP_KEEP,
815            StencilOperation depthFailOp = SOP_KEEP,
816            StencilOperation passOp = SOP_KEEP,
817            bool twoSidedOperation = false) = 0;
818
819
820
821                /** Sets the current vertex declaration, ie the source of vertex data. */
822                virtual void setVertexDeclaration(VertexDeclaration* decl) = 0;
823                /** Sets the current vertex buffer binding state. */
824                virtual void setVertexBufferBinding(VertexBufferBinding* binding) = 0;
825
826        /** Sets whether or not normals are to be automatically normalised.
827        @remarks
828            This is useful when, for example, you are scaling SceneNodes such that
829            normals may not be unit-length anymore. Note though that this has an
830            overhead so should not be turn on unless you really need it.
831        @par
832            You should not normally call this direct unless you are rendering
833            world geometry; set it on the Renderable because otherwise it will be
834            overridden by material settings.
835        */
836        virtual void setNormaliseNormals(bool normalise) = 0;
837
838        /**
839          Render something to the active viewport.
840
841          Low-level rendering interface to perform rendering
842          operations. Unlikely to be used directly by client
843          applications, since the SceneManager and various support
844          classes will be responsible for calling this method.
845          Can only be called between _beginScene and _endScene
846
847          @param op A rendering operation instance, which contains
848            details of the operation to be performed.
849         */
850        virtual void _render(const RenderOperation& op);
851
852                /** Gets the capabilities of the render system. */
853                const RenderSystemCapabilities* getCapabilities(void) const { return mCapabilities; }
854
855        /** Binds a given GpuProgram (but not the parameters).
856        @remarks Only one GpuProgram of each type can be bound at once, binding another
857        one will simply replace the exsiting one.
858        */
859        virtual void bindGpuProgram(GpuProgram* prg) = 0;
860
861        /** Bind Gpu program parameters. */
862        virtual void bindGpuProgramParameters(GpuProgramType gptype, GpuProgramParametersSharedPtr params) = 0;
863        /** Unbinds GpuPrograms of a given GpuProgramType.
864        @remarks
865            This returns the pipeline to fixed-function processing for this type.
866        */
867        virtual void unbindGpuProgram(GpuProgramType gptype) = 0;
868
869        /** sets the clipping region.
870        */
871        virtual void setClipPlanes(const PlaneList& clipPlanes) = 0;
872
873        /** Utility method for initialising all render targets attached to this rendering system. */
874        virtual void _initRenderTargets(void);
875
876        /** Utility method to notify all render targets that a camera has been removed,
877            incase they were referring to it as their viewer.
878        */
879        virtual void _notifyCameraRemoved(const Camera* cam);
880
881        /** Internal method for updating all render targets attached to this rendering system. */
882        virtual void _updateAllRenderTargets(void);
883
884        /** Set a clipping plane. */
885        virtual void setClipPlane (ushort index, const Plane &p);
886        /** Set a clipping plane. */
887        virtual void setClipPlane (ushort index, Real A, Real B, Real C, Real D) = 0;
888        /** Enable the clipping plane. */
889        virtual void enableClipPlane (ushort index, bool enable) = 0;
890
891        /** Sets whether or not vertex windings set should be inverted; this can be important
892            for rendering reflections. */
893        virtual void setInvertVertexWinding(bool invert);
894        /** Sets the 'scissor region' ie the region of the target in which rendering can take place.
895        @remarks
896            This method allows you to 'mask off' rendering in all but a given rectangular area
897            as identified by the parameters to this method.
898        @note
899            Not all systems support this method. Check the RenderSystemCapabilities for the
900            RSC_SCISSOR_TEST capability to see if it is supported.
901        @param enabled True to enable the scissor test, false to disable it.
902        @param left, top, right, bottom The location of the corners of the rectangle, expressed in
903            <i>pixels</i>.
904        */
905        virtual void setScissorTest(bool enabled, size_t left = 0, size_t top = 0,
906            size_t right = 800, size_t bottom = 600) = 0;
907
908        /** Clears one or more frame buffers on the active render target.
909        @param buffers Combination of one or more elements of FrameBufferType
910            denoting which buffers are to be cleared
911        @param colour The colour to clear the colour buffer with, if enabled
912        @param depth The value to initialise the depth buffer with, if enabled
913        @param stencil The value to initialise the stencil buffer with, if enabled.
914        */
915        virtual void clearFrameBuffer(unsigned int buffers,
916            const ColourValue& colour = ColourValue::Black,
917            Real depth = 1.0f, unsigned short stencil = 0) = 0;
918        /** Returns the horizontal texel offset value required for mapping
919            texel origins to pixel origins in this rendersystem.
920        @remarks
921            Since rendersystems sometimes disagree on the origin of a texel,
922            mapping from texels to pixels can sometimes be problematic to
923            implement generically. This method allows you to retrieve the offset
924            required to map the origin of a texel to the origin of a pixel in
925            the horizontal direction.
926        */
927        virtual Real getHorizontalTexelOffset(void) = 0;
928        /** Returns the vertical texel offset value required for mapping
929        texel origins to pixel origins in this rendersystem.
930        @remarks
931        Since rendersystems sometimes disagree on the origin of a texel,
932        mapping from texels to pixels can sometimes be problematic to
933        implement generically. This method allows you to retrieve the offset
934        required to map the origin of a texel to the origin of a pixel in
935        the vertical direction.
936        */
937        virtual Real getVerticalTexelOffset(void) = 0;
938
939        /** Gets the minimum (closest) depth value to be used when rendering
940            using identity transforms.
941        @remarks
942            When using identity transforms you can manually set the depth
943            of a vertex; however the input values required differ per
944            rendersystem. This method lets you retrieve the correct value.
945        @see Renderable::useIdentityView, Renderable::useIdentityProjection
946        */
947        virtual Real getMinimumDepthInputValue(void) = 0;
948        /** Gets the maximum (farthest) depth value to be used when rendering
949            using identity transforms.
950        @remarks
951            When using identity transforms you can manually set the depth
952            of a vertex; however the input values required differ per
953            rendersystem. This method lets you retrieve the correct value.
954        @see Renderable::useIdentityView, Renderable::useIdentityProjection
955        */
956        virtual Real getMaximumDepthInputValue(void) = 0;
957
958                /** Defines a listener on the custom events that this render system
959                        can raise.
960                @see RenderSystem::addListener
961                */
962                class _OgreExport Listener
963                {
964                public:
965                        Listener() {}
966                        virtual ~Listener() {}
967
968                        /** A rendersystem-specific event occurred.
969                        @param eventName The name of the event which has occurred
970                        @param parameters A list of parameters that may belong to this event,
971                                may be null if there are no parameters
972                        */
973                        virtual void eventOccurred(const String& eventName,
974                                const NameValuePairList* parameters = 0) = 0;
975                };
976                /** Adds a listener to the custom events that this render system can raise.
977                @remarks
978                        Some render systems have quite specific, internally generated events
979                        that the application may wish to be notified of. Many applications
980                        don't have to worry about these events, and can just trust OGRE to
981                        handle them, but if you want to know, you can add a listener here.
982                @par
983                        Events are raised very generically by string name. Perhaps the most
984                        common example of a render system specific event is the loss and
985                        restoration of a device in DirectX; which OGRE deals with, but you
986                        may wish to know when it happens.
987                @see RenderSystem::getRenderSystemEvents
988                */
989                virtual void addListener(Listener* l);
990                /** Remove a listener to the custom events that this render system can raise.
991                */
992                virtual void removeListener(Listener* l);
993
994                /** Gets a list of the rendersystem specific events that this rendersystem
995                        can raise.
996                @see RenderSystem::addListener
997                */
998                virtual const StringVector& getRenderSystemEvents(void) const { return mEventNames; }
999    protected:
1000
1001
1002        /** The render targets. */
1003        RenderTargetMap mRenderTargets;
1004                /** The render targets, ordered by priority. */
1005                RenderTargetPriorityMap mPrioritisedRenderTargets;
1006                /** The Active render target. */
1007                RenderTarget * mActiveRenderTarget;
1008
1009        // Texture manager
1010        // A concrete class of this will be created and
1011        // made available under the TextureManager singleton,
1012        // managed by the RenderSystem
1013        TextureManager* mTextureManager;
1014
1015        /// Used to store the capabilities of the graphics card
1016        RenderSystemCapabilities* mCapabilities;
1017
1018        // Active viewport (dest for future rendering operations)
1019        Viewport* mActiveViewport;
1020
1021        CullingMode mCullingMode;
1022
1023        bool mVSync;
1024                bool mWBuffer;
1025
1026        size_t mFaceCount;
1027        size_t mVertexCount;
1028
1029        /// Saved set of world matrices
1030        Matrix4 mWorldMatrices[256];
1031
1032                /// Saved manual colour blends
1033                ColourValue mManualBlendColours[OGRE_MAX_TEXTURE_LAYERS][2];
1034
1035        bool mInvertVertexWinding;
1036
1037                /// List of names of events this rendersystem may raise
1038                StringVector mEventNames;
1039
1040                /// Internal method for firing a rendersystem event
1041                virtual void fireEvent(const String& name, const NameValuePairList* params = 0);
1042
1043                typedef std::list<Listener*> ListenerList;
1044                ListenerList mEventListeners;
1045
1046    };
1047}
1048
1049#endif
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