/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://ogre.sourceforge.net/
Copyright (c) 2000-2005 The OGRE Team
Also see acknowledgements in Readme.html
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/
#ifndef __RenderSystem_H_
#define __RenderSystem_H_
// Precompiler options
#include "OgrePrerequisites.h"
#include "OgreString.h"
#include "OgreTextureUnitState.h"
#include "OgreCommon.h"
#include "OgreRenderOperation.h"
#include "OgreRenderSystemCapabilities.h"
#include "OgreRenderTarget.h"
#include "OgreRenderTexture.h"
#include "OgreFrameListener.h"
#include "OgreConfigOptionMap.h"
#include "OgreGpuProgram.h"
#include "OgrePlane.h"
#include "OgreIteratorWrappers.h"
namespace Ogre
{
typedef std::map< String, RenderTarget * > RenderTargetMap;
typedef std::multimap
final = (texture * sourceFactor) + (pixel * destFactor)
Each of the factors is specified as one of a number of options, as specified in the SceneBlendFactor enumerated type. @param sourceFactor The source factor in the above calculation, i.e. multiplied by the texture colour components. @param destFactor The destination factor in the above calculation, i.e. multiplied by the pixel colour components. */ virtual void _setSceneBlending(SceneBlendFactor sourceFactor, SceneBlendFactor destFactor) = 0; /** Sets the global alpha rejection approach for future renders. By default images are rendered regardless of texture alpha. This method lets you change that. @param func The comparison function which must pass for a pixel to be written. @param val The value to compare each pixels alpha value to (0-255) */ virtual void _setAlphaRejectSettings(CompareFunction func, unsigned char value) = 0; /** * Signifies the beginning of a frame, ie the start of rendering on a single viewport. Will occur * several times per complete frame if multiple viewports exist. */ virtual void _beginFrame(void) = 0; /** * Ends rendering of a frame to the current viewport. */ virtual void _endFrame(void) = 0; /** Sets the provided viewport as the active one for future rendering operations. This viewport is aware of it's own camera and render target. Must be implemented by subclass. @param target Pointer to the appropriate viewport. */ virtual void _setViewport(Viewport *vp) = 0; /** Get the current active viewport for rendering. */ virtual Viewport* _getViewport(void); /** Sets the culling mode for the render system based on the 'vertex winding'. A typical way for the rendering engine to cull triangles is based on the 'vertex winding' of triangles. Vertex winding refers to the direction in which the vertices are passed or indexed to in the rendering operation as viewed from the camera, and will wither be clockwise or anticlockwise (that's 'counterclockwise' for you Americans out there ;) The default is CULL_CLOCKWISE i.e. that only triangles whose vertices are passed/indexed in anticlockwise order are rendered - this is a common approach and is used in 3D studio models for example. You can alter this culling mode if you wish but it is not advised unless you know what you are doing. You may wish to use the CULL_NONE option for mesh data that you cull yourself where the vertex winding is uncertain. */ virtual void _setCullingMode(CullingMode mode) = 0; virtual CullingMode _getCullingMode(void) const; /** Sets the mode of operation for depth buffer tests from this point onwards. Sometimes you may wish to alter the behaviour of the depth buffer to achieve special effects. Because it's unlikely that you'll set these options for an entire frame, but rather use them to tweak settings between rendering objects, this is an internal method (indicated by the '_' prefix) which will be used by a SceneManager implementation rather than directly from the client application. If this method is never called the settings are automatically the same as the default parameters. @param depthTest If true, the depth buffer is tested for each pixel and the frame buffer is only updated if the depth function test succeeds. If false, no test is performed and pixels are always written. @param depthWrite If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds. If false, the depth buffer is left unchanged even if a new pixel is written. @param depthFunction Sets the function required for the depth test. */ virtual void _setDepthBufferParams(bool depthTest = true, bool depthWrite = true, CompareFunction depthFunction = CMPF_LESS_EQUAL) = 0; /** Sets whether or not the depth buffer check is performed before a pixel write. @param enabled If true, the depth buffer is tested for each pixel and the frame buffer is only updated if the depth function test succeeds. If false, no test is performed and pixels are always written. */ virtual void _setDepthBufferCheckEnabled(bool enabled = true) = 0; /** Sets whether or not the depth buffer is updated after a pixel write. @param enabled If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds. If false, the depth buffer is left unchanged even if a new pixel is written. */ virtual void _setDepthBufferWriteEnabled(bool enabled = true) = 0; /** Sets the comparison function for the depth buffer check. Advanced use only - allows you to choose the function applied to compare the depth values of new and existing pixels in the depth buffer. Only an issue if the deoth buffer check is enabled (see _setDepthBufferCheckEnabled) @param func The comparison between the new depth and the existing depth which must return true for the new pixel to be written. */ virtual void _setDepthBufferFunction(CompareFunction func = CMPF_LESS_EQUAL) = 0; /** Sets whether or not colour buffer writing is enabled, and for which channels. @remarks For some advanced effects, you may wish to turn off the writing of certain colour channels, or even all of the colour channels so that only the depth buffer is updated in a rendering pass. However, the chances are that you really want to use this option through the Material class. @param red, green, blue, alpha Whether writing is enabled for each of the 4 colour channels. */ virtual void _setColourBufferWriteEnabled(bool red, bool green, bool blue, bool alpha) = 0; /** Sets the depth bias, NB you should use the Material version of this. @remarks When polygons are coplanar, you can get problems with 'depth fighting' where the pixels from the two polys compete for the same screen pixel. This is particularly a problem for decals (polys attached to another surface to represent details such as bulletholes etc.). @par A way to combat this problem is to use a depth bias to adjust the depth buffer value used for the decal such that it is slightly higher than the true value, ensuring that the decal appears on top. @param bias The bias value, should be between 0 and 16. */ virtual void _setDepthBias(ushort bias) = 0; /** Sets the fogging mode for future geometry. @param mode Set up the mode of fog as described in the FogMode enum, or set to FOG_NONE to turn off. @param colour The colour of the fog. Either set this to the same as your viewport background colour, or to blend in with a skydome or skybox. @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 that fog never completely obscures the scene. @param linearStart Distance at which linear fog starts to encroach. The distance must be passed 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. @param linearEnd Distance at which linear fog becomes completely opaque.The distance must be passed 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. */ 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; /** The RenderSystem will keep a count of tris rendered, this resets the count. */ virtual void _beginGeometryCount(void); /** Reports the number of tris rendered since the last _beginGeometryCount call. */ virtual unsigned int _getFaceCount(void) const; /** Reports the number of vertices passed to the renderer since the last _beginGeometryCount call. */ virtual unsigned int _getVertexCount(void) const; /** Generates a packed data version of the passed in ColourValue suitable for use as with this RenderSystem. @remarks Since different render systems have different colour data formats (eg RGBA for GL, ARGB for D3D) this method allows you to use 1 method for all. @param colour The colour to convert @param pDest Pointer to location to put the result. */ virtual void convertColourValue(const ColourValue& colour, uint32* pDest) = 0; /** Builds a perspective projection matrix suitable for this render system. @remarks Because different APIs have different requirements (some incompatible) for the projection matrix, this method allows each to implement their own correctly and pass back a generic OGRE matrix for storage in the engine. */ virtual void _makeProjectionMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane, Matrix4& dest, bool forGpuProgram = false) = 0; /** Builds a perspective projection matrix for the case when frustum is not centered around camera. @remarks Viewport coordinates are in camera coordinate frame, i.e. camera is at the origin. */ virtual void _makeProjectionMatrix(Real left, Real right, Real bottom, Real top, Real nearPlane, Real farPlane, Matrix4& dest, bool forGpuProgram = false) = 0; /** Builds an orthographic projection matrix suitable for this render system. @remarks Because different APIs have different requirements (some incompatible) for the projection matrix, this method allows each to implement their own correctly and pass back a generic OGRE matrix for storage in the engine. */ virtual void _makeOrthoMatrix(const Radian& fovy, Real aspect, Real nearPlane, Real farPlane, Matrix4& dest, bool forGpuProgram = false) = 0; /** Update a perspective projection matrix to use 'oblique depth projection'. @remarks This method can be used to change the nature of a perspective transform in order to make the near plane not perpendicular to the camera view direction, but to be at some different orientation. This can be useful for performing arbitrary clipping (e.g. to a reflection plane) which could otherwise only be done using user clip planes, which are more expensive, and not necessarily supported on all cards. @param matrix The existing projection matrix. Note that this must be a perspective transform (not orthographic), and must not have already been altered by this method. The matrix will be altered in-place. @param plane The plane which is to be used as the clipping plane. This plane must be in CAMERA (view) space. @param forGpuProgram Is this for use with a Gpu program or fixed-function */ virtual void _applyObliqueDepthProjection(Matrix4& matrix, const Plane& plane, bool forGpuProgram) = 0; /** Sets how to rasterise triangles, as points, wireframe or solid polys. */ virtual void _setRasterisationMode(SceneDetailLevel level) = 0; /** Turns stencil buffer checking on or off. @remarks Stencilling (masking off areas of the rendering target based on the stencil buffer) canbe turned on or off using this method. By default, stencilling is disabled. */ virtual void setStencilCheckEnabled(bool enabled) = 0; /** Determines if this system supports hardware accelerated stencil buffer. @remarks Note that the lack of this function doesn't mean you can't do stencilling, but the stencilling operations will be provided in software, which will NOT be fast. @par Generally hardware stencils are only supported in 32-bit colour modes, because the stencil buffer shares the memory of the z-buffer, and in most cards the z-buffer has to be the same depth as the colour buffer. This means that in 32-bit mode, 24 bits of the z-buffer are depth and 8 bits are stencil. In 16-bit mode there is no room for a stencil (although some cards support a 15:1 depth:stencil option, this isn't useful for very much) so 8 bits of stencil are provided in software. This can mean that if you use stencilling, your applications may be faster in 32-but colour than in 16-bit, which may seem odd to some people. */ /*virtual bool hasHardwareStencil(void) = 0;*/ /** This method allows you to set all the stencil buffer parameters in one call. @remarks The stencil buffer is used to mask out pixels in the render target, allowing you to do effects like mirrors, cut-outs, stencil shadows and more. Each of your batches of rendering is likely to ignore the stencil buffer, update it with new values, or apply it to mask the output of the render. The stencil test is:(Reference Value & Mask) CompareFunction (Stencil Buffer Value & Mask)The result of this will cause one of 3 actions depending on whether the test fails, succeeds but with the depth buffer check still failing, or succeeds with the depth buffer check passing too. @par Unlike other render states, stencilling is left for the application to turn on and off when it requires. This is because you are likely to want to change parameters between batches of arbitrary objects and control the ordering yourself. In order to batch things this way, you'll want to use OGRE's separate render queue groups (see RenderQueue) and register a RenderQueueListener to get notifications between batches. @par There are individual state change methods for each of the parameters set using this method. Note that the default values in this method represent the defaults at system start up too. @param func The comparison function applied. @param refValue The reference value used in the comparison @param mask The bitmask applied to both the stencil value and the reference value before comparison @param stencilFailOp The action to perform when the stencil check fails @param depthFailOp The action to perform when the stencil check passes, but the depth buffer check still fails @param passOp The action to take when both the stencil and depth check pass. @param twoSidedOperation If set to true, then if you render both back and front faces (you'll have to turn off culling) then these parameters will apply for front faces, and the inverse of them will happen for back faces (keep remains the same). */ virtual void setStencilBufferParams(CompareFunction func = CMPF_ALWAYS_PASS, uint32 refValue = 0, uint32 mask = 0xFFFFFFFF, StencilOperation stencilFailOp = SOP_KEEP, StencilOperation depthFailOp = SOP_KEEP, StencilOperation passOp = SOP_KEEP, bool twoSidedOperation = false) = 0; /** Sets the current vertex declaration, ie the source of vertex data. */ virtual void setVertexDeclaration(VertexDeclaration* decl) = 0; /** Sets the current vertex buffer binding state. */ virtual void setVertexBufferBinding(VertexBufferBinding* binding) = 0; /** Sets whether or not normals are to be automatically normalised. @remarks This is useful when, for example, you are scaling SceneNodes such that normals may not be unit-length anymore. Note though that this has an overhead so should not be turn on unless you really need it. @par You should not normally call this direct unless you are rendering world geometry; set it on the Renderable because otherwise it will be overridden by material settings. */ virtual void setNormaliseNormals(bool normalise) = 0; /** Render something to the active viewport. Low-level rendering interface to perform rendering operations. Unlikely to be used directly by client applications, since the SceneManager and various support classes will be responsible for calling this method. Can only be called between _beginScene and _endScene @param op A rendering operation instance, which contains details of the operation to be performed. */ virtual void _render(const RenderOperation& op); /** Gets the capabilities of the render system. */ const RenderSystemCapabilities* getCapabilities(void) const { return mCapabilities; } /** Binds a given GpuProgram (but not the parameters). @remarks Only one GpuProgram of each type can be bound at once, binding another one will simply replace the exsiting one. */ virtual void bindGpuProgram(GpuProgram* prg) = 0; /** Bind Gpu program parameters. */ virtual void bindGpuProgramParameters(GpuProgramType gptype, GpuProgramParametersSharedPtr params) = 0; /** Unbinds GpuPrograms of a given GpuProgramType. @remarks This returns the pipeline to fixed-function processing for this type. */ virtual void unbindGpuProgram(GpuProgramType gptype) = 0; /** sets the clipping region. */ virtual void setClipPlanes(const PlaneList& clipPlanes) = 0; /** Utility method for initialising all render targets attached to this rendering system. */ virtual void _initRenderTargets(void); /** Utility method to notify all render targets that a camera has been removed, incase they were referring to it as their viewer. */ virtual void _notifyCameraRemoved(const Camera* cam); /** Internal method for updating all render targets attached to this rendering system. */ virtual void _updateAllRenderTargets(void); /** Set a clipping plane. */ virtual void setClipPlane (ushort index, const Plane &p); /** Set a clipping plane. */ virtual void setClipPlane (ushort index, Real A, Real B, Real C, Real D) = 0; /** Enable the clipping plane. */ virtual void enableClipPlane (ushort index, bool enable) = 0; /** Sets whether or not vertex windings set should be inverted; this can be important for rendering reflections. */ virtual void setInvertVertexWinding(bool invert); /** Sets the 'scissor region' ie the region of the target in which rendering can take place. @remarks This method allows you to 'mask off' rendering in all but a given rectangular area as identified by the parameters to this method. @note Not all systems support this method. Check the RenderSystemCapabilities for the RSC_SCISSOR_TEST capability to see if it is supported. @param enabled True to enable the scissor test, false to disable it. @param left, top, right, bottom The location of the corners of the rectangle, expressed in pixels. */ virtual void setScissorTest(bool enabled, size_t left = 0, size_t top = 0, size_t right = 800, size_t bottom = 600) = 0; /** Clears one or more frame buffers on the active render target. @param buffers Combination of one or more elements of FrameBufferType denoting which buffers are to be cleared @param colour The colour to clear the colour buffer with, if enabled @param depth The value to initialise the depth buffer with, if enabled @param stencil The value to initialise the stencil buffer with, if enabled. */ virtual void clearFrameBuffer(unsigned int buffers, const ColourValue& colour = ColourValue::Black, Real depth = 1.0f, unsigned short stencil = 0) = 0; /** Returns the horizontal texel offset value required for mapping texel origins to pixel origins in this rendersystem. @remarks Since rendersystems sometimes disagree on the origin of a texel, mapping from texels to pixels can sometimes be problematic to implement generically. This method allows you to retrieve the offset required to map the origin of a texel to the origin of a pixel in the horizontal direction. */ virtual Real getHorizontalTexelOffset(void) = 0; /** Returns the vertical texel offset value required for mapping texel origins to pixel origins in this rendersystem. @remarks Since rendersystems sometimes disagree on the origin of a texel, mapping from texels to pixels can sometimes be problematic to implement generically. This method allows you to retrieve the offset required to map the origin of a texel to the origin of a pixel in the vertical direction. */ virtual Real getVerticalTexelOffset(void) = 0; /** Gets the minimum (closest) depth value to be used when rendering using identity transforms. @remarks When using identity transforms you can manually set the depth of a vertex; however the input values required differ per rendersystem. This method lets you retrieve the correct value. @see Renderable::useIdentityView, Renderable::useIdentityProjection */ virtual Real getMinimumDepthInputValue(void) = 0; /** Gets the maximum (farthest) depth value to be used when rendering using identity transforms. @remarks When using identity transforms you can manually set the depth of a vertex; however the input values required differ per rendersystem. This method lets you retrieve the correct value. @see Renderable::useIdentityView, Renderable::useIdentityProjection */ virtual Real getMaximumDepthInputValue(void) = 0; /** Defines a listener on the custom events that this render system can raise. @see RenderSystem::addListener */ class _OgreExport Listener { public: Listener() {} virtual ~Listener() {} /** A rendersystem-specific event occurred. @param eventName The name of the event which has occurred @param parameters A list of parameters that may belong to this event, may be null if there are no parameters */ virtual void eventOccurred(const String& eventName, const NameValuePairList* parameters = 0) = 0; }; /** Adds a listener to the custom events that this render system can raise. @remarks Some render systems have quite specific, internally generated events that the application may wish to be notified of. Many applications don't have to worry about these events, and can just trust OGRE to handle them, but if you want to know, you can add a listener here. @par Events are raised very generically by string name. Perhaps the most common example of a render system specific event is the loss and restoration of a device in DirectX; which OGRE deals with, but you may wish to know when it happens. @see RenderSystem::getRenderSystemEvents */ virtual void addListener(Listener* l); /** Remove a listener to the custom events that this render system can raise. */ virtual void removeListener(Listener* l); /** Gets a list of the rendersystem specific events that this rendersystem can raise. @see RenderSystem::addListener */ virtual const StringVector& getRenderSystemEvents(void) const { return mEventNames; } protected: /** The render targets. */ RenderTargetMap mRenderTargets; /** The render targets, ordered by priority. */ RenderTargetPriorityMap mPrioritisedRenderTargets; /** The Active render target. */ RenderTarget * mActiveRenderTarget; // Texture manager // A concrete class of this will be created and // made available under the TextureManager singleton, // managed by the RenderSystem TextureManager* mTextureManager; /// Used to store the capabilities of the graphics card RenderSystemCapabilities* mCapabilities; // Active viewport (dest for future rendering operations) Viewport* mActiveViewport; CullingMode mCullingMode; bool mVSync; bool mWBuffer; size_t mFaceCount; size_t mVertexCount; /// Saved set of world matrices Matrix4 mWorldMatrices[256]; /// Saved manual colour blends ColourValue mManualBlendColours[OGRE_MAX_TEXTURE_LAYERS][2]; bool mInvertVertexWinding; /// List of names of events this rendersystem may raise StringVector mEventNames; /// Internal method for firing a rendersystem event virtual void fireEvent(const String& name, const NameValuePairList* params = 0); typedef std::list