418 lines
14 KiB
C++
418 lines
14 KiB
C++
/** Example 027 Post Processing
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This tutorial shows how to implement post processing for D3D9 and OpenGL with
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the engine. In order to do post processing, scene objects are firstly rendered
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to render target. With the help of screen quad, the render target texture
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is then drawn on the quad with shader-defined effects applied.
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This tutorial shows how to create a screen quad. It also shows how to create a
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render target texture and associate it with the quad. Effects are defined as
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shaders which are applied during rendering the quad with the render target
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texture attached to it.
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A simple color inverse example is presented in this tutorial. The effect is
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written in HLSL and GLSL.
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@author Boshen Guan
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We include all headers and define necessary variables as we have done before.
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*/
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#include <irrlicht.h>
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#include "driverChoice.h"
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#include "exampleHelper.h"
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using namespace irr;
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#ifdef _MSC_VER
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#pragma comment(lib, "Irrlicht.lib")
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#endif
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/*
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We write a class derived from IShaderConstantSetCallBack class and implement
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OnSetConstants callback interface. In this callback, we will set constants
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used by the shader.
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In this example, our HLSL shader needs texture size as input in its vertex
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shader. Therefore, we set texture size in OnSetConstants callback using
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setVertexShaderConstant function.
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*/
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IrrlichtDevice* device = 0;
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video::ITexture* rt = 0;
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class QuadShaderCallBack : public video::IShaderConstantSetCallBack
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{
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public:
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QuadShaderCallBack() : FirstUpdate(true), TextureSizeID(-1), TextureSamplerID(-1)
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{ }
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virtual void OnSetConstants(video::IMaterialRendererServices* services,
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s32 userData)
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{
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core::dimension2d<u32> size = rt->getSize();
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// get texture size array
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f32 textureSize[] =
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{
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(f32)size.Width, (f32)size.Height
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};
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if ( FirstUpdate )
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{
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TextureSizeID = services->getVertexShaderConstantID("TextureSize");
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TextureSamplerID = services->getPixelShaderConstantID("TextureSampler");
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}
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// set texture size to vertex shader
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services->setVertexShaderConstant(TextureSizeID, reinterpret_cast<f32*>(textureSize), 2);
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// set texture for an OpenGL driver
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s32 textureLayer = 0;
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services->setPixelShaderConstant(TextureSamplerID, &textureLayer, 1);
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}
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private:
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bool FirstUpdate;
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s32 TextureSizeID;
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s32 TextureSamplerID;
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};
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class ScreenQuad : public IReferenceCounted
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{
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public:
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ScreenQuad(video::IVideoDriver* driver)
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: Driver(driver)
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{
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// --------------------------------> u
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// |[1](-1, 1)----------[2](1, 1)
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// | | ( 0, 0) / | (1, 0)
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// | | / |
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// | | / |
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// | | / |
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// | | / |
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// | | / |
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// | | / |
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// | | / |
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// | | / |
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// |[0](-1, -1)---------[3](1, -1)
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// | ( 0, 1) (1, 1)
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// V
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// v
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/*
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A screen quad is composed of two adjacent triangles with 4 vertices.
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Vertex [0], [1] and [2] create the first triangle and Vertex [0],
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[2] and [3] create the second one. To map texture on the quad, UV
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coordinates are assigned to the vertices. The origin of UV coordinate
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locates on the top-left corner. And the value of UVs range from 0 to 1.
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*/
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// define vertices array
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Vertices[0] = irr::video::S3DVertex(-1.0f, -1.0f, 0.0f, 1, 1, 0, irr::video::SColor(0,255,255,255), 0.0f, 1.0f);
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Vertices[1] = irr::video::S3DVertex(-1.0f, 1.0f, 0.0f, 1, 1, 0, irr::video::SColor(0,255,255,255), 0.0f, 0.0f);
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Vertices[2] = irr::video::S3DVertex( 1.0f, 1.0f, 0.0f, 1, 1, 0, irr::video::SColor(0,255,255,255), 1.0f, 0.0f);
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Vertices[3] = irr::video::S3DVertex( 1.0f, -1.0f, 0.0f, 1, 1, 0, irr::video::SColor(0,255,255,255), 1.0f, 1.0f);
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// define indices for triangles
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Indices[0] = 0;
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Indices[1] = 1;
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Indices[2] = 2;
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Indices[3] = 0;
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Indices[4] = 2;
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Indices[5] = 3;
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// turn off lighting as default
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Material.setFlag(video::EMF_LIGHTING, false);
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// set texture warp settings to clamp to edge pixel
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for (u32 i = 0; i < video::MATERIAL_MAX_TEXTURES; i++)
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{
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Material.TextureLayer[i].TextureWrapU = video::ETC_CLAMP_TO_EDGE;
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Material.TextureLayer[i].TextureWrapV = video::ETC_CLAMP_TO_EDGE;
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}
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}
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virtual ~ScreenQuad() {}
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//! render the screen quad
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virtual void render()
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{
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// set the material of screen quad
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Driver->setMaterial(Material);
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// set matrices to fit the quad to full viewport
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Driver->setTransform(video::ETS_WORLD, core::IdentityMatrix);
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Driver->setTransform(video::ETS_VIEW, core::IdentityMatrix);
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Driver->setTransform(video::ETS_PROJECTION, core::IdentityMatrix);
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// draw screen quad
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Driver->drawVertexPrimitiveList(Vertices, 4, Indices, 2);
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}
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//! sets a flag of material to a new value
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virtual void setMaterialFlag(video::E_MATERIAL_FLAG flag, bool newvalue)
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{
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Material.setFlag(flag, newvalue);
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}
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//! sets the texture of the specified layer in material to the new texture.
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void setMaterialTexture(u32 textureLayer, video::ITexture* texture)
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{
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Material.setTexture(textureLayer, texture);
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}
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//! sets the material type to a new material type.
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virtual void setMaterialType(video::E_MATERIAL_TYPE newType)
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{
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Material.MaterialType = newType;
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}
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private:
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video::IVideoDriver *Driver;
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video::S3DVertex Vertices[4];
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u16 Indices[6];
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video::SMaterial Material;
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};
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/*
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We start up the engine just like before. Then shader programs are selected
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according to the driver type.
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*/
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int main()
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{
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// ask user for driver
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video::E_DRIVER_TYPE driverType=driverChoiceConsole();
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if (driverType==video::EDT_COUNT)
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return 1;
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// create device
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device = createDevice(driverType, core::dimension2d<u32>(640, 480));
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if (device == 0)
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return 1; // could not create selected driver.
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video::IVideoDriver* driver = device->getVideoDriver();
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scene::ISceneManager* smgr = device->getSceneManager();
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/*
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In this example, high level post processing shaders are loaded for both
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Direct3D and OpenGL drivers.
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File pp_d3d9.hlsl is for Direct3D 9, and pp_opengl.frag/pp_opengl.vert
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are for OpenGL.
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*/
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const io::path mediaPath = getExampleMediaPath();
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io::path vsFileName; // filename for the vertex shader
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io::path psFileName; // filename for the pixel shader
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switch(driverType)
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{
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case video::EDT_DIRECT3D9:
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psFileName = mediaPath + "pp_d3d9.hlsl";
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vsFileName = psFileName; // both shaders are in the same file
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break;
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case video::EDT_OPENGL:
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case video::EDT_BURNINGSVIDEO:
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psFileName = mediaPath + "pp_opengl.frag";
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vsFileName = mediaPath + "pp_opengl.vert";
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break;
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}
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/*
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Check for hardware capability of executing the corresponding shaders
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on selected renderer. This is not necessary though.
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*/
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if (!driver->queryFeature(video::EVDF_PIXEL_SHADER_1_1) &&
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!driver->queryFeature(video::EVDF_ARB_FRAGMENT_PROGRAM_1))
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{
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device->getLogger()->log("WARNING: Pixel shaders disabled "\
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"because of missing driver/hardware support.");
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psFileName = "";
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}
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if (!driver->queryFeature(video::EVDF_VERTEX_SHADER_1_1) &&
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!driver->queryFeature(video::EVDF_ARB_VERTEX_PROGRAM_1))
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{
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device->getLogger()->log("WARNING: Vertex shaders disabled "\
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"because of missing driver/hardware support.");
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vsFileName = "";
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}
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/*
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An animated mesh is loaded to be displayed. As in most examples,
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we'll take the fairy md2 model.
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*/
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// load and display animated fairy mesh
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scene::IAnimatedMeshSceneNode* fairy = smgr->addAnimatedMeshSceneNode(
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smgr->getMesh(mediaPath + "faerie.md2"));
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if (fairy)
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{
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fairy->setMaterialTexture(0,
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driver->getTexture(mediaPath + "faerie2.bmp")); // set diffuse texture
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fairy->setMaterialFlag(video::EMF_LIGHTING, false); // disable dynamic lighting
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fairy->setPosition(core::vector3df(-10,0,-100));
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fairy->setMD2Animation ( scene::EMAT_STAND );
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}
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// add scene camera
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smgr->addCameraSceneNode(0, core::vector3df(10,10,-80),
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core::vector3df(-10,10,-100));
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/*
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We create a render target texture (RTT) with the same size as frame buffer.
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Instead of rendering the scene directly to the frame buffer, we firstly
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render it to this RTT. Post processing is then applied based on this RTT.
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RTT size needs not to be the same with frame buffer though. However in this
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example, we expect the result of rendering to RTT to be consistent with the
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result of rendering directly to the frame buffer. Therefore, the size of
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RTT keeps the same with frame buffer.
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*/
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// create render target
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if (driver->queryFeature(video::EVDF_RENDER_TO_TARGET))
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{
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rt = driver->addRenderTargetTexture(core::dimension2d<u32>(640, 480), "RTT1");
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}
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else
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{
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device->getLogger()->log("Your hardware or this renderer is not able to use the "\
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"render to texture feature. RTT Disabled.");
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}
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/*
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Post processing is achieved by rendering a screen quad with this RTT (with
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previously rendered result) as a texture on the quad. A screen quad is
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geometry of flat plane composed of two adjacent triangles covering the
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entire area of viewport. In this pass of rendering, RTT works just like
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a normal texture and is drawn on the quad during rendering. We can then
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take control of this rendering process by applying various shader-defined
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materials to the quad. In other words, we can achieve different effect by
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writing different shaders.
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This process is called post processing because it normally does not rely
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on scene geometry. The inputs of this process are just textures, or in
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other words, just images. With the help of screen quad, we can draw these
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images on the screen with different effects. For example, we can adjust
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contrast, make grayscale, add noise, do more fancy effect such as blur,
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bloom, ghost, or just like in this example, we invert the color to produce
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negative image.
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Note that post processing is not limited to use only one texture. It can
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take multiple textures as shader inputs to provide desired result. In
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addition, post processing can also be chained to produce compound result.
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*/
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// we create a screen quad
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ScreenQuad *screenQuad = new ScreenQuad(driver);
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// turn off mip maps and bilinear filter since we do not want interpolated result
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screenQuad->setMaterialFlag(video::EMF_USE_MIP_MAPS, false);
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screenQuad->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
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// set quad texture to RTT we just create
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screenQuad->setMaterialTexture(0, rt);
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/*
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Let's create material for the quad. Like in other example, we create material
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using IGPUProgrammingServices and call addShaderMaterialFromFiles, which
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returns a material type identifier.
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*/
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// create materials
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video::IGPUProgrammingServices* gpu = driver->getGPUProgrammingServices();
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s32 ppMaterialType = 0;
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if (gpu)
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{
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// We write a QuadShaderCallBack class that implements OnSetConstants
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// callback of IShaderConstantSetCallBack class at the beginning of
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// this tutorial. We set shader constants in this callback.
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// create an instance of callback class
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QuadShaderCallBack* mc = new QuadShaderCallBack();
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// create material from post processing shaders
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ppMaterialType = gpu->addHighLevelShaderMaterialFromFiles(
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vsFileName, "vertexMain", video::EVST_VS_1_1,
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psFileName, "pixelMain", video::EPST_PS_1_1, mc);
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mc->drop();
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}
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// set post processing material type to the quad
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screenQuad->setMaterialType((video::E_MATERIAL_TYPE)ppMaterialType);
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/*
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Now draw everything. That's all.
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*/
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int lastFPS = -1;
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while(device->run())
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{
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if (device->isWindowActive())
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{
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driver->beginScene(true, true, video::SColor(255,0,0,0));
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if (rt)
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{
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// draw scene into render target
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// set render target to RTT
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driver->setRenderTarget(rt, true, true, video::SColor(255,0,0,0));
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// draw scene to RTT just like normal rendering
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smgr->drawAll();
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// after rendering to RTT, we change render target back
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driver->setRenderTarget(0, true, true, video::SColor(255,0,0,0));
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// render screen quad to apply post processing
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screenQuad->render();
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}
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else
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{
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// draw scene normally
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smgr->drawAll();
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}
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driver->endScene();
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int fps = driver->getFPS();
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if (lastFPS != fps)
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{
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core::stringw str = L"Irrlicht Engine - Post processing example [";
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str += driver->getName();
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str += "] FPS:";
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str += fps;
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device->setWindowCaption(str.c_str());
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lastFPS = fps;
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}
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}
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}
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// do not forget to manually drop the screen quad
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screenQuad->drop();
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device->drop();
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return 0;
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}
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/*
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**/
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