Implement IBL diffuse part
[opengl.git] / skybox.cpp
index 45ab4eacaa8ecf31d5ce50e92470d04d92186fbe..ab492ca9a330129a660421999ef7a330fe2c360b 100644 (file)
@@ -2,13 +2,17 @@
 #include "skybox.hpp"
 #include <glm/gtc/type_ptr.hpp>
 
+GLuint setupCubeVertices(GLuint progId, bool reverse = false);
+
 Skybox::Skybox(const Image img): program("skyboxvert.glsl", "skyboxfrag.glsl") {
-       Program equiProg("equirectangularvert.glsl", "equirectangularfrag.glsl");
+       Program equiProg("skyboxvert.glsl", "equirectangularfrag.glsl");
        glUseProgram(equiProg.progId);
 
-       GLuint equiTexId;
-       glGenTextures(1, &equiTexId);
-       glBindTexture(GL_TEXTURE_2D, equiTexId);
+       GLuint allTexIds[3];
+       glGenTextures(3, allTexIds);
+       hdrTexId = allTexIds[0], cubemapTexId = allTexIds[1], irradianceTexId = allTexIds[2];
+       
+       glBindTexture(GL_TEXTURE_2D, hdrTexId);
 
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16, img.width(), img.height(), 0, GL_RGB, GL_UNSIGNED_SHORT, (unsigned short*)img.data());
 
@@ -27,9 +31,8 @@ Skybox::Skybox(const Image img): program("skyboxvert.glsl", "skyboxfrag.glsl") {
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 512, 512);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, captureFBO);
 
-       // generate and setup cubemap texture
-       glGenTextures(1, &texId);
-       glBindTexture(GL_TEXTURE_CUBE_MAP, texId);
+       // setup cubemap texture
+       glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexId);
        for (GLuint i = 0; i < 6; i++)
                glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, 512, 512, 0, GL_RGB, GL_FLOAT, nullptr);
        glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
@@ -38,21 +41,8 @@ Skybox::Skybox(const Image img): program("skyboxvert.glsl", "skyboxfrag.glsl") {
        glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
-       // generate cube to render
-       glGenVertexArrays(1, &vao);
-       glBindVertexArray(vao);
-
-       GLuint vbo;
-       glGenBuffers(1, &vbo);
-
-       auto vertices = cube();
-
-       glBindBuffer(GL_ARRAY_BUFFER, vbo);
-       glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
-       
-       GLuint posLoc = glGetAttribLocation(program.progId, "pos");
-       glEnableVertexAttribArray(posLoc);
-       glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+       // generate vertices
+       setupCubeVertices(equiProg.progId);
 
        // render the cube
        glm::mat4 captureProj = glm::perspective(glm::radians(90.f), 1.f, 0.1f, 10.f);
@@ -68,36 +58,58 @@ Skybox::Skybox(const Image img): program("skyboxvert.glsl", "skyboxfrag.glsl") {
        glUniform1i(glGetUniformLocation(equiProg.progId, "equirectangularMap"), 0);
        glUniformMatrix4fv(glGetUniformLocation(equiProg.progId, "projection"), 1, GL_FALSE, glm::value_ptr(captureProj));
        glActiveTexture(GL_TEXTURE0);
-       glBindTexture(GL_TEXTURE_2D, equiTexId);
+       glBindTexture(GL_TEXTURE_2D, hdrTexId);
 
        glViewport(0, 0, 512, 512);
        glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
        for (GLuint i = 0; i < 6; i++) {
                glUniformMatrix4fv(glGetUniformLocation(equiProg.progId, "view"), 1, GL_FALSE, glm::value_ptr(captureViews[i]));
-               glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, texId, 0);
+               glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, cubemapTexId, 0);
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                glDrawArrays(GL_TRIANGLES, 0, 36);
        }
 
+       // setup irradiance map texture
+       glBindTexture(GL_TEXTURE_CUBE_MAP, irradianceTexId);
+       for (GLuint i = 0; i < 6; i++)
+               glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, 32, 32, 0, GL_RGB, GL_FLOAT, nullptr);
+       glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+       glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+       glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+       glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+       glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 
-       // switch back to regular skybox shader
-       glUseProgram(program.progId);
-       glDepthFunc(GL_LEQUAL);
+       // bind framebuffers for rendering irradiance map into
+       glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+       glBindRenderbuffer(GL_RENDERBUFFER, captureRBO);
+       glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 32, 32);
        
-       glGenVertexArrays(1, &vao);
-       glBindVertexArray(vao);
+       Program irradianceProg("skyboxvert.glsl", "irradiancefrag.glsl");
+       glUseProgram(irradianceProg.progId);
+       glUniform1i(glGetUniformLocation(irradianceProg.progId, "environmentMap"), 0);
+       glUniformMatrix4fv(glGetUniformLocation(irradianceProg.progId, "projection"), 1, GL_FALSE, glm::value_ptr(captureProj));
+       glActiveTexture(GL_TEXTURE0);
+       glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexId);
 
-       glGenBuffers(1, &vbo);
+       // generate vertices
+       setupCubeVertices(irradianceProg.progId);
 
-       // reverse so facing inside out
-       std::reverse(vertices.begin(), vertices.end());
+       // render irradiance map
+       glViewport(0, 0, 32, 32);
+       glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+       for (GLuint i = 0; i < 6; i++) {
+               glUniformMatrix4fv(glGetUniformLocation(irradianceProg.progId, "view"), 1, GL_FALSE, glm::value_ptr(captureViews[i]));
+               glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, irradianceTexId, 0);
+               glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+               glDrawArrays(GL_TRIANGLES, 0, 36);
+       }
 
-       glBindBuffer(GL_ARRAY_BUFFER, vbo);
-       glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
+       // switch back to regular skybox shader
+       glUseProgram(program.progId);
+       glDepthFunc(GL_LEQUAL);
 
-       posLoc = glGetAttribLocation(program.progId, "pos");
-       glEnableVertexAttribArray(posLoc);
-       glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+       // reverse so facing inside out
+       vao = setupCubeVertices(program.progId, true);
 
        // restore default framebuffer
        glBindFramebuffer(GL_FRAMEBUFFER, 0);
@@ -116,12 +128,31 @@ void Skybox::draw(glm::mat4 proj, glm::mat4 view) const {
        glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
 
        glActiveTexture(GL_TEXTURE0);
-       glBindTexture(GL_TEXTURE_CUBE_MAP, texId);
+       glBindTexture(GL_TEXTURE_CUBE_MAP, irradianceTexId);
        glDrawArrays(GL_TRIANGLES, 0, 36);
 
        if (glGetError()) exit(1);
 }
 
-GLuint Skybox::getTexture() const {
-       return texId;
+GLuint setupCubeVertices(GLuint progId, bool reverse) {
+       GLuint vao;
+       glGenVertexArrays(1, &vao);
+       glBindVertexArray(vao);
+
+       GLuint vbo;
+       glGenBuffers(1, &vbo);
+
+       auto vertices = cube();
+
+       if (reverse)
+               std::reverse(vertices.begin(), vertices.end());
+
+       glBindBuffer(GL_ARRAY_BUFFER, vbo);
+       glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
+       
+       GLuint posLoc = glGetAttribLocation(progId, "pos");
+       glEnableVertexAttribArray(posLoc);
+       glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+       
+       return vao;
 }