Do ex2

src/utilities/glutils.cpp

@@ -2,7 +2,7 @@
 #include <program.hpp>
 #include "glutils.h"
 
-unsigned int generateBuffer(Mesh &mesh) {
+unsigned int generateBuffer(Mesh &mesh, bool isNormalMapped) {
     unsigned int vaoID;
     glGenVertexArrays(1, &vaoID);
     glBindVertexArray(vaoID);
@@ -26,6 +26,93 @@ unsigned int generateBuffer(Mesh &mesh) {
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBufferID);
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, mesh.indices.size() * sizeof(unsigned int), mesh.indices.data(), GL_STATIC_DRAW);
 
+    if (mesh.textureCoordinates.empty()) return vaoID;
+    
+    unsigned int textureBufferID;
+    glGenBuffers(1, &textureBufferID);
+    glBindBuffer(GL_ARRAY_BUFFER, textureBufferID);
+    glBufferData(GL_ARRAY_BUFFER, mesh.textureCoordinates.size() * sizeof(glm::vec2), mesh.textureCoordinates.data(), GL_STATIC_DRAW);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), 0);
+    glEnableVertexAttribArray(2);
+
+    if (isNormalMapped) addTangents(vaoID, mesh);
 
     return vaoID;
 }
+
+void addTangents(unsigned int vaoID, Mesh& mesh) {
+    glm::vec3 tangents[mesh.vertices.size()];
+    glm::vec3 bitangents[mesh.vertices.size()];
+    
+    for (unsigned int i = 0; i < mesh.indices.size(); i+=3) {
+        const glm::vec3& pos1 = mesh.vertices[mesh.indices[i+0]];
+        const glm::vec3& pos2 = mesh.vertices[mesh.indices[i+1]];
+        const glm::vec3& pos3 = mesh.vertices[mesh.indices[i+2]];
+        
+        const glm::vec2& uv1 = mesh.textureCoordinates[mesh.indices[i+0]];
+        const glm::vec2& uv2 = mesh.textureCoordinates[mesh.indices[i+1]];
+        const glm::vec2& uv3 = mesh.textureCoordinates[mesh.indices[i+2]];
+        
+        glm::vec3 edge1 = pos2 - pos1;
+        glm::vec3 edge2 = pos3 - pos1;
+        glm::vec2 deltaUV1 = uv2 - uv1;
+        glm::vec2 deltaUV2 = uv3 - uv1;
+
+        float f = 1.0f / (deltaUV1.x * deltaUV2.y - deltaUV2.x * deltaUV1.y);
+        
+        glm::vec3 tangent, bitangent;
+        tangent.x = f * (deltaUV2.y * edge1.x - deltaUV1.y * edge2.x);
+        tangent.y = f * (deltaUV2.y * edge1.y - deltaUV1.y * edge2.y);
+        tangent.z = f * (deltaUV2.y * edge1.z - deltaUV1.y * edge2.z);
+
+        bitangent.x = f * (-deltaUV2.x * edge1.x + deltaUV1.x * edge2.x);
+        bitangent.y = f * (-deltaUV2.x * edge1.y + deltaUV1.x * edge2.y);
+        bitangent.z = f * (-deltaUV2.x * edge1.z + deltaUV1.x * edge2.z);
+        
+        tangent = glm::normalize(tangent);
+        bitangent = glm::normalize(bitangent);
+        
+        // handedness
+        tangents[i+0] = -tangent;
+        tangents[i+1] = -tangent;
+        tangents[i+2] = -tangent;
+        bitangents[i+0] = -bitangent;
+        bitangents[i+1] = -bitangent;
+        bitangents[i+2] = -bitangent;
+    }
+    
+    glBindVertexArray(vaoID);
+    
+    unsigned int tangentBufferID;
+    glGenBuffers(1, &tangentBufferID);
+    glBindBuffer(GL_ARRAY_BUFFER, tangentBufferID);
+    glBufferData(GL_ARRAY_BUFFER, mesh.vertices.size() * sizeof(glm::vec3), tangents, GL_STATIC_DRAW);
+    glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), 0);
+    glEnableVertexAttribArray(3);
+    
+    unsigned int bitangentBufferID;
+    glGenBuffers(1, &bitangentBufferID);
+    glBindBuffer(GL_ARRAY_BUFFER, bitangentBufferID);
+    glBufferData(GL_ARRAY_BUFFER, mesh.vertices.size() * sizeof(glm::vec3), bitangents, GL_STATIC_DRAW);
+    glVertexAttribPointer(4, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), 0);
+    glEnableVertexAttribArray(4);
+}
+
+unsigned int generateTexture(PNGImage& texture) {
+    unsigned int id;
+    glGenTextures(1, &id);
+    glBindTexture(GL_TEXTURE_2D, id);
+    
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+    
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture.width, texture.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture.pixels.data());
+    //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, texture.width, texture.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture.pixels.data());
+    
+    glGenerateMipmap(GL_TEXTURE_2D);
+    
+    return id;
+}