X-Git-Url: http://git.lukelau.me/?p=opengl.git;a=blobdiff_plain;f=skybox.cpp;fp=skybox.cpp;h=45ab4eacaa8ecf31d5ce50e92470d04d92186fbe;hp=79ce9d022029cf121fc51c02f1cf05e67026382a;hb=a03f2bc751bbd7f91cbc2f52d2f0f6e753d6f776;hpb=210d1b08cec40845d849e89baea8a9cc96917f60

diff --git a/skybox.cpp b/skybox.cpp
index 79ce9d0..45ab4ea 100644
--- a/skybox.cpp
+++ b/skybox.cpp
@@ -1,26 +1,44 @@
 #include "shapes.hpp"
 #include "skybox.hpp"
-#include "image.hpp"
 #include <glm/gtc/type_ptr.hpp>
 
-Skybox::Skybox(const std::vector<std::string> faces): program("skyboxvert.glsl", "skyboxfrag.glsl") {
-	glGenTextures(1, &texId);
-	glBindTexture(GL_TEXTURE_CUBE_MAP, texId);
-	glDepthFunc(GL_LEQUAL);
+Skybox::Skybox(const Image img): program("skyboxvert.glsl", "skyboxfrag.glsl") {
+	Program equiProg("equirectangularvert.glsl", "equirectangularfrag.glsl");
+	glUseProgram(equiProg.progId);
 	
-	int width, height, numChans;
-	for (int i = 0; i < faces.size(); i++) {
-		Image img(faces[i]);
+	GLuint equiTexId;
+	glGenTextures(1, &equiTexId);
+	glBindTexture(GL_TEXTURE_2D, equiTexId);
 
-		glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGBA, img.width(), img.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, img.data());
-	}
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16, img.width(), img.height(), 0, GL_RGB, GL_UNSIGNED_SHORT, (unsigned short*)img.data());
 
-	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+	// generate framebuffers to store cubemap in
+	GLuint captureFBO, captureRBO;
+	glGenFramebuffers(1, &captureFBO);
+	glGenRenderbuffers(1, &captureRBO);
+
+	glBindFramebuffer(GL_FRAMEBUFFER, captureFBO);
+	glBindRenderbuffer(GL_RENDERBUFFER, captureRBO);
+	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);
+	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);
 	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);
 
+	// generate cube to render
 	glGenVertexArrays(1, &vao);
 	glBindVertexArray(vao);
 
@@ -29,15 +47,60 @@ Skybox::Skybox(const std::vector<std::string> faces): program("skyboxvert.glsl",
 
 	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);
+
+	// render the cube
+	glm::mat4 captureProj = glm::perspective(glm::radians(90.f), 1.f, 0.1f, 10.f);
+	glm::mat4 captureViews[] = {
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3( 1,  0,  0), glm::vec3(0, -1,  0)),
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3(-1,  0,  0), glm::vec3(0, -1,  0)),
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3( 0,  1,  0), glm::vec3(0,  0,  1)),
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3( 0, -1,  0), glm::vec3(0,  0, -1)),
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3( 0,  0,  1), glm::vec3(0, -1,  0)),
+		glm::lookAt(glm::vec3(0, 0, 0), glm::vec3( 0,  0, -1), glm::vec3(0, -1,  0))
+	};
+
+	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);
+
+	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);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+	}
+	
+	
+	// switch back to regular skybox shader
+	glUseProgram(program.progId);
+	glDepthFunc(GL_LEQUAL);
+
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+
+	glGenBuffers(1, &vbo);
+
 	// reverse so facing inside out
 	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(program.progId, "pos");
+	posLoc = glGetAttribLocation(program.progId, "pos");
 	glEnableVertexAttribArray(posLoc);
 	glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	// restore default framebuffer
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
 void Skybox::draw(glm::mat4 proj, glm::mat4 view) const {
@@ -55,6 +118,8 @@ void Skybox::draw(glm::mat4 proj, glm::mat4 view) const {
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_CUBE_MAP, texId);
 	glDrawArrays(GL_TRIANGLES, 0, 36);
+
+	if (glGetError()) exit(1);
 }
 
 GLuint Skybox::getTexture() const {