irrlicht/include/IShaderConstantSetCallBack.h
cutealien 16c960c5ed Add IShaderConstantSetCallBack::OnCreate to allow earlier access to IMaterialRendererServices
Accessing IMaterialRendererServices outside of OnSetConstants can be useful and Irrlicht made this a bit too hard to access.
Also OnCreate allows actually for nicer code where initialization and update of shader constants are strictly separated (see changed example).

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6465 dfc29bdd-3216-0410-991c-e03cc46cb475
2023-04-21 14:41:01 +00:00

93 lines
3.6 KiB
C++

// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#ifndef IRR_I_SHADER_CONSTANT_SET_CALLBACT_H_INCLUDED
#define IRR_I_SHADER_CONSTANT_SET_CALLBACT_H_INCLUDED
#include "IReferenceCounted.h"
namespace irr
{
namespace video
{
class IMaterialRendererServices;
class SMaterial;
//! Interface making it possible to set constants for gpu programs every frame.
/** Implement this interface in an own class and pass a pointer to it to one of
the methods in IGPUProgrammingServices when creating a shader. The
OnSetConstants method will be called every frame now. */
class IShaderConstantSetCallBack : public virtual IReferenceCounted
{
public:
//! Called by the engine after a shader material has been created successfully
/** If you are using one callback instance per shader (much recommended)
this is a good place to get shader constant id's for high level shaders.
\param services: Pointer to an interface providing methods to set/get the constants for the shader.
\param userData: Userdata int which can be specified when creating the shader. */
virtual void OnCreate(IMaterialRendererServices* services, s32 userData) { }
//! Called to let the callBack know the used material (optional method)
/**
\code
class MyCallBack : public IShaderConstantSetCallBack
{
const video::SMaterial *UsedMaterial;
OnSetMaterial(const video::SMaterial& material)
{
UsedMaterial=&material;
}
OnSetConstants(IMaterialRendererServices* services, s32 userData)
{
services->setVertexShaderConstant("myColor", reinterpret_cast<f32*>(&UsedMaterial->color), 4);
}
}
\endcode
*/
virtual void OnSetMaterial(const SMaterial& material) { }
//! Called by the engine when the vertex and/or pixel shader constants for an material renderer should be set.
/**
Implement the IShaderConstantSetCallBack in an own class and implement your own
OnSetConstants method using the given IMaterialRendererServices interface.
Pass a pointer to this class to one of the methods in IGPUProgrammingServices
when creating a shader. The OnSetConstants method will now be called every time
before geometry is being drawn using your shader material. A sample implementation
would look like this:
\code
virtual void OnSetConstants(video::IMaterialRendererServices* services, s32 userData)
{
video::IVideoDriver* driver = services->getVideoDriver();
// set clip matrix at register 4
core::matrix4 worldViewProj(driver->getTransform(video::ETS_PROJECTION));
worldViewProj *= driver->getTransform(video::ETS_VIEW);
worldViewProj *= driver->getTransform(video::ETS_WORLD);
services->setVertexShaderConstant(&worldViewProj.M[0], 4, 4);
// for high level shading languages, this would be another solution:
//services->setVertexShaderConstant("mWorldViewProj", worldViewProj.M, 16);
// set some light color at register 9
video::SColorf col(0.0f,1.0f,1.0f,0.0f);
services->setVertexShaderConstant(reinterpret_cast<const f32*>(&col), 9, 1);
// for high level shading languages, this would be another solution:
//services->setVertexShaderConstant("myColor", reinterpret_cast<f32*>(&col), 4);
}
\endcode
\param services: Pointer to an interface providing methods to set the constants for the shader.
\param userData: Userdata int which can be specified when creating the shader.
*/
virtual void OnSetConstants(IMaterialRendererServices* services, s32 userData) = 0;
};
} // end namespace video
} // end namespace irr
#endif