Purpose of the Sample:
This sample demonstrates how to do shadow mapping.
CGame.h
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#ifndef __CGAME__ #define __CGAME__ #include <glad/glad.h> #include "shader_s.h" #include "Model.h" #include "glm/mat4x4.hpp" #include "glm/vec3.hpp" #include "glm/glm.hpp" #include "glm/gtc/matrix_transform.hpp" #include "glm/gtc/type_ptr.hpp" class Model; class Mesh; struct GfxContext { glm::mat4 worldMatrix; glm::mat4 viewMatrix; glm::mat4 projectionMatrix; glm::mat4 mvpMatrix; glm::vec3 eyePos; glm::vec3 lightDirection; glm::mat4 lightViewProjectionMatrix; float time; }; class CGame { public: CGame() {}; void Initialize(unsigned int screenWidth, unsigned int screenHeight); void Shutdown(); void Render(); void OnResize(int screenWidth, int screenHeight); void ReloadShaders(); private: void SetupGPUProgram(); void SetupModel(); void DrawModel(Model& model, Shader& shader, GfxContext& context); void DrawScene(Shader* replacementShader); void RenderShadowMap(); void RenderScene(); void ResolveToScreen(); void CreateMSAAFBO(); void CreateShadowMapFBO(); Shader* m_pShaderPass0; Shader* m_pShaderPass1; Shader* m_ShadowMapShader; Model* m_pManModel; Model* m_pQuad; Model* m_pTorus; GLuint m_ColorTextureId; GLuint m_DepthStencilTextureId; GLuint m_IntermediateFBOId; GLuint m_ShadowMapNullColorTextureId; GLuint m_ShadowMapDepthStencilTextureId; GLuint m_ShadowMapFBOId; unsigned int m_Width; unsigned int m_Height; }; #endif |
CGame.cpp
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#include "CGame.h" #define STB_IMAGE_IMPLEMENTATION #include "stb_image/stb_image.h" #include "Mesh.h" #include GfxContext gfxContext; void CGame::Initialize(unsigned int screenWidth, unsigned int screenHeight) { m_Width = screenWidth; m_Height = screenHeight; SetupGPUProgram(); SetupModel(); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LEQUAL); glEnable(GL_MULTISAMPLE); glEnable(GL_STENCIL_TEST); CreateMSAAFBO(); CreateShadowMapFBO(); glBindFramebuffer(GL_FRAMEBUFFER, 0); } void CGame::CreateMSAAFBO() { glGenFramebuffers(1, &m_IntermediateFBOId); glBindFramebuffer(GL_FRAMEBUFFER, m_IntermediateFBOId); glGenTextures(1, &m_ColorTextureId); glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, m_ColorTextureId); glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB8, m_Width, m_Height, GL_TRUE); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, m_ColorTextureId, 0); glGenTextures(1, &m_DepthStencilTextureId); glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, m_DepthStencilTextureId); glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_DEPTH24_STENCIL8, m_Width, m_Height, GL_TRUE); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D_MULTISAMPLE, m_DepthStencilTextureId, 0); if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) { int a = 0; ++a; } } void CGame::CreateShadowMapFBO() { int shadowTextureWidth = 1024; int shadowTextureHeight = 1024; glGenFramebuffers(1, &m_ShadowMapFBOId); glBindFramebuffer(GL_FRAMEBUFFER, m_ShadowMapFBOId); glGenTextures(1, &m_ShadowMapDepthStencilTextureId); glBindTexture(GL_TEXTURE_2D, m_ShadowMapDepthStencilTextureId); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, shadowTextureWidth, shadowTextureHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER); float borderColor[] = { 1.0f, 1.0f, 1.0f, 1.0f }; glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, m_ShadowMapDepthStencilTextureId, 0); if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) { // Great! } } void CGame::Shutdown() { } void CGame::OnResize(int width, int height) { m_Width = width; m_Height = height; glViewport(0, 0, m_Width, m_Height); glScissor(0, 0, m_Width, m_Height); } void CGame::DrawModel(Model& model, Shader& shader, GfxContext& context) { gfxContext.mvpMatrix = gfxContext.projectionMatrix * gfxContext.viewMatrix * gfxContext.worldMatrix; shader.setMatrix4x4("modelMatrix", glm::value_ptr(gfxContext.worldMatrix)); shader.setMatrix4x4("viewMatrix", glm::value_ptr(gfxContext.viewMatrix)); shader.setMatrix4x4("projectionMatrix", glm::value_ptr(gfxContext.projectionMatrix)); shader.setMatrix4x4("mvpMatrix", glm::value_ptr(gfxContext.mvpMatrix)); shader.setVector3("eyePos", glm::value_ptr(gfxContext.eyePos)); shader.setVector3("lightDirection", glm::value_ptr(gfxContext.lightDirection)); shader.setMatrix4x4("lightViewProjMatrix", glm::value_ptr(gfxContext.lightViewProjectionMatrix)); shader.setFloat("time", gfxContext.time); model.meshes[0].Draw(shader); } void CGame::RenderShadowMap() { const char* debugGroupName = "Render Shadow Maps"; glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, strlen(debugGroupName), debugGroupName); glDisable(GL_MULTISAMPLE); glBindFramebuffer(GL_FRAMEBUFFER, m_ShadowMapFBOId); glViewport(0, 0, 1024, 1024); glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); glClearDepth(1.0f); glClear(GL_DEPTH_BUFFER_BIT); glEnable(GL_CULL_FACE); glCullFace(GL_FRONT); DrawScene(m_ShadowMapShader); glCullFace(GL_BACK); glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); glPopDebugGroup(); } void CGame::RenderScene() { const char* debugGroupName = "Render Scene"; glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, strlen(debugGroupName), debugGroupName); glEnable(GL_MULTISAMPLE); glBindFramebuffer(GL_FRAMEBUFFER, m_IntermediateFBOId); glViewport(0, 0, m_Width, m_Height); glClearColor(0.1f, 0.1f, 0.1f, 1.0f); glClearDepth(1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); glEnable(GL_CULL_FACE); glFrontFace(GL_CCW); glCullFace(GL_BACK); DrawScene(NULL); glPopDebugGroup(); } void CGame::ResolveToScreen() { const char* debugGroupName = "Resolve To Screen"; glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, strlen(debugGroupName), debugGroupName); // Blit intermediate FBO to backbuffer FBO glBindFramebuffer(GL_READ_FRAMEBUFFER, m_IntermediateFBOId); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0); glBlitFramebuffer(0, 0, m_Width, m_Height, 0, 0, m_Width, m_Height, GL_COLOR_BUFFER_BIT, GL_NEAREST); glPopDebugGroup(); } void CGame::DrawScene(Shader* replacementShader) { Shader* shaderToUse = replacementShader != NULL ? replacementShader : m_pShaderPass0; // Light Matrices glm::vec3 lightPosition = glm::vec3(-5, 5, 10); gfxContext.lightDirection = glm::normalize(glm::vec3(0, 0, 0) - lightPosition); glm::mat4 lightViewMatrix = glm::lookAt(lightPosition, glm::vec3(0, 0, 0), glm::vec3(0, 1, 0)); float orthoProjScale = 5.0f; glm::mat4 lightProjectionMatrix = glm::ortho(-orthoProjScale, orthoProjScale, -orthoProjScale, orthoProjScale, 0.01f, 100.0f); gfxContext.lightViewProjectionMatrix = lightProjectionMatrix * lightViewMatrix; // Setup View Matrix const float degreesPerSecond = 45.0f; glm::mat4 viewRotation = glm::rotate(glm::mat4(), glm::radians(glm::radians(25.0f) * gfxContext.time), glm::vec3(0, 1, 0)); float x = cos(glm::radians(degreesPerSecond) * gfxContext.time) * 4.5f; float z = sin(glm::radians(degreesPerSecond) * gfxContext.time) * 4.5f; gfxContext.eyePos = glm::vec4(x, 3.0f, z, 0.0f); gfxContext.viewMatrix = glm::lookAt(gfxContext.eyePos, glm::vec3(0, 1, 0), glm::vec3(0, 1, 0)); gfxContext.projectionMatrix = glm::perspective(glm::radians(60.0f), m_Width / static_cast(m_Height), 0.03f, 100.0f); // Draw Man float scaleFactor = 0.4f; gfxContext.worldMatrix = glm::scale(glm::mat4(1.0f), glm::vec3(scaleFactor, scaleFactor, scaleFactor)); gfxContext.worldMatrix = glm::rotate(gfxContext.worldMatrix, glm::radians(0.0f), glm::vec3(0, 1, 0)); glm::vec3 diffuseColor = glm::vec3(1, 0, 0); shaderToUse->use(); shaderToUse->setVector3("diffuseColor", glm::value_ptr(diffuseColor)); DrawModel(*m_pManModel, *shaderToUse, gfxContext); // Draw Torus scaleFactor = 0.3f; gfxContext.worldMatrix = glm::scale(glm::mat4(1.0f), glm::vec3(scaleFactor, scaleFactor, scaleFactor)); gfxContext.worldMatrix = glm::translate(gfxContext.worldMatrix, glm::vec3(-5, 7, -10)); gfxContext.worldMatrix = glm::rotate(gfxContext.worldMatrix, glm::radians(360.0f) * gfxContext.time, glm::vec3(0, 1, 0)); diffuseColor = glm::vec3(1, 1, 0); shaderToUse->use(); shaderToUse->setVector3("diffuseColor", glm::value_ptr(diffuseColor)); DrawModel(*m_pTorus, *shaderToUse, gfxContext); // Draw a Floor quad diffuseColor = glm::vec3(0.8f, 0.8f, 0.8f); if (replacementShader == NULL) { shaderToUse = m_pShaderPass1; glActiveTexture(0); glBindTexture(GL_TEXTURE_2D, m_ShadowMapDepthStencilTextureId); } shaderToUse->use(); shaderToUse->setVector3("diffuseColor", glm::value_ptr(diffuseColor)); gfxContext.worldMatrix = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, -0.01f, 0.0f)); gfxContext.worldMatrix = glm::scale(gfxContext.worldMatrix, glm::vec3(100.0f, 100.0f, 100.0f)); gfxContext.worldMatrix = glm::rotate(gfxContext.worldMatrix, glm::radians(0.0f), glm::vec3(0, 1, 0)); DrawModel(*m_pQuad, *shaderToUse, gfxContext); glBindTexture(GL_TEXTURE_2D, 0); } void CGame::Render() { static auto startTime = std::chrono::high_resolution_clock::now(); auto currentTime = std::chrono::high_resolution_clock::now(); gfxContext.time = std::chrono::duration<float, std::chrono::seconds::period>(currentTime - startTime).count(); RenderShadowMap(); RenderScene(); ResolveToScreen(); } void CGame::SetupModel() { m_pManModel = new Model(); m_pManModel->Load("man.obj"); m_pTorus = new Model(); m_pTorus->Load("torus.obj"); m_pQuad = new Model(); m_pQuad->Load("quad.obj"); } void CGame::SetupGPUProgram() { m_pShaderPass0 = new Shader("vertexPass0.glsl", "fragmentPass0.glsl"); m_pShaderPass1 = new Shader("vertexPass1.glsl", "fragmentPass1.glsl"); m_ShadowMapShader = new Shader("shadowMapVertex.glsl", "shadowMapFragment.glsl"); } void CGame::ReloadShaders() { OutputDebugStringA("Reloading Shaders!\n"); SetupGPUProgram(); } |
vertexPass0.glsl
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#version 330 core layout (location = 0) in vec3 position; layout (location = 1) in vec3 normal; uniform mat4 modelMatrix; uniform mat4 viewMatrix; uniform mat4 projectionMatrix; uniform mat4 mvpMatrix; uniform vec3 eyePos; uniform vec3 lightDirection; uniform mat4 lightViewProjMatrix; uniform float time; uniform vec3 diffuseColor; uniform vec3 specularColor; out vec3 fsNormal; out vec3 fsUV; out vec3 fsFragPos; out vec4 fsShadowPos; void main() { vec4 pos = mvpMatrix * vec4(position.xyz, 1); fsNormal = vec3(modelMatrix * vec4(normal, 0)).xyz; fsFragPos = vec3(modelMatrix * vec4(position.xyz, 0)).xyz; gl_Position = pos; } |
fragmentPass0.glsl
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#version 330 core out vec4 FragColor; in vec3 fsNormal; in vec3 fsFragPos; uniform vec3 eyePos; uniform vec3 lightDirection; uniform vec3 diffuseColor; uniform vec3 specularColor; vec3 calculateDirectionalLighting(vec3 lightDir, vec3 normal, vec3 viewDir) { float di = clamp(dot(normal, lightDir), 0, 1); vec3 half = normalize( lightDir + viewDir ); float si = clamp(dot(normal, half), 0, 1); float ki = 0.01; vec3 ambient = ki * vec3(1); vec3 diffuse = di * diffuseColor; vec3 specular = pow(si, 20.0) * vec3(1); vec3 finalColor = ambient + diffuse + specular; return finalColor; } void main() { vec3 viewDir = normalize(eyePos - fsFragPos); vec3 normal = normalize(fsNormal); vec3 finalColor = calculateDirectionalLighting(-lightDirection, normal, viewDir); FragColor = vec4(finalColor, 1.0f); } |
vertexPass1.glsl
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#version 330 core layout (location = 0) in vec3 position; layout (location = 1) in vec3 normal; layout (location = 2) in vec3 uv; uniform mat4 modelMatrix; uniform mat4 viewMatrix; uniform mat4 projectionMatrix; uniform mat4 mvpMatrix; uniform vec3 eyePos; uniform vec3 lightDirection; uniform mat4 lightViewProjMatrix; uniform float time; uniform vec3 diffuseColor; uniform vec3 specularColor; out vec3 fsNormal; out vec3 fsUV; out vec3 fsFragPos; out vec4 fsShadowPos; void main() { vec4 pos = mvpMatrix * vec4(position.xyz, 1); fsNormal = vec3(modelMatrix * vec4(normal, 0)).xyz; fsFragPos = vec3(modelMatrix * vec4(position.xyz, 1)).xyz; fsShadowPos = lightViewProjMatrix * vec4(fsFragPos.xyz,1); fsUV = uv; gl_Position = pos; } |
fragmentPass1.glsl
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#version 330 core out vec4 FragColor; in vec3 fsNormal; in vec3 fsUV; in vec3 fsFragPos; in vec4 fsShadowPos; uniform mat4 modelMatrix; uniform mat4 viewMatrix; uniform mat4 projectionMatrix; uniform mat4 mvpMatrix; uniform vec3 eyePos; uniform vec3 lightDirection; uniform mat4 lightViewProjMatrix; uniform float time; uniform vec3 diffuseColor; uniform vec3 specularColor; uniform sampler2D shadowMapTexture; float generateCheckerboard(vec2 uv) { vec2 p = floor(uv*100.0); float s = mod( p.x + p.y, 2.0 ); return s; } vec3 calculateDirectionalLighting(vec3 lightDir, vec3 normal, vec3 viewDir, vec2 uv, float shadowIntensity) { normal = vec3(0,1,0); float di = clamp(dot(normal, lightDir), 0, 1); vec3 half = normalize( lightDir + viewDir ); float si = clamp(dot(normal, half), 0, 1); float ki = 0.2; vec3 ambient = (ki * vec3(1.0)) * (1.0-shadowIntensity); vec3 diffuse = di * (diffuseColor * generateCheckerboard(uv)); vec3 specular = pow(si, 10.0) * vec3(0.5); vec3 finalColor = ambient + diffuse + specular; return finalColor; } float calculateShadowIntensity(vec4 shadowPos) { vec3 shadowCoord = (shadowPos.xyz/shadowPos.w) * 0.5 + 0.5; float currentDepth = shadowCoord.z; float closestDepth = texture(shadowMapTexture, shadowCoord.xy).r; if(currentDepth > 1.0) { return 0.0; } float bias = 0.0001; float shadow = 0.0; if((currentDepth - bias) > closestDepth) { shadow = 1.0; } return shadow; } void main() { vec3 viewDir = normalize(eyePos - fsFragPos); vec3 normal = normalize(fsNormal); float shadowIntensity = calculateShadowIntensity(fsShadowPos); vec3 finalColor = calculateDirectionalLighting(-lightDirection, normal, viewDir, fsUV.xy, shadowIntensity); FragColor = vec4(finalColor, 1.0f); } |
shadowMapVertex.glsl
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#version 330 core layout (location = 0) in vec3 position; layout (location = 1) in vec3 normal; uniform mat4 modelMatrix; uniform mat4 lightViewProjMatrix; void main() { gl_Position = lightViewProjMatrix * modelMatrix * vec4(position.xyz, 1); } |
shadowMapFragment.glsl
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#version 330 core out vec4 FragColor; void main() { FragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f); } |
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