basic lighting

src/engine/shaders.cpp

@@ -92,6 +92,10 @@ void Shader::setMat4(const std::string &name, const glm::mat4 &mat) const {
     glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), 1, GL_FALSE, &mat[0][0]);
 }
 
+void Shader::setVec3(const std::string &name, const glm::vec3 &vec) const {
+    glUniform3fv(glGetUniformLocation(ID, name.c_str()), 1, &vec[0]);
+}
+
 Shader::~Shader() {
     if (ID != 0) {
         glDeleteProgram(ID);

src/main.cpp

@@ -1,3 +1,4 @@
+#define GL_GLEXT_PROTOTYPES
 #include "engine/sdl.hpp"
 #include "engine/opengl.hpp"
 #include "engine/obj_loader.hpp"
@@ -10,7 +11,7 @@ int main(int argc, char* argv[]) {
     glEnable(GL_DEPTH_TEST); 
 
     Camera camera(
-        glm::vec3(3.0f, 4.0f, 6.0f), // Position
+        glm::vec3(5.0f, 2.0f, 4.0f), // Position
         glm::vec3(0.0f, 1.0f, 0.0f), // Target
         glm::vec3(0.0f, 1.0f, 0.0f)  // Up vector
     );
@@ -22,17 +23,24 @@ int main(int argc, char* argv[]) {
         100.0f               // Far Plane
     );
 
-    Shader shader_program("shaders/triangle.vert", "shaders/triangle.frag");
+    Shader cubeShader("shaders/triangle.vert", "shaders/triangle.frag");
+    Shader lightShader("shaders/triangle.vert", "shaders/triangle_light_source.frag");
 
-    OBJLoader objLoader("assets/models/Sci-fi_Container_Game.obj");
-    if (!objLoader.isLoaded()) {
+    OBJLoader mainObj("assets/models/Sci-fi_Container_Game.obj");
+    if (!mainObj.isLoaded()) {
+        SDL_Log("Failed to load OBJ model.");
+        return -1;
+    }
+
+    OBJLoader lightObj("assets/models/cube.obj");
+    if (!lightObj.isLoaded()) {
         SDL_Log("Failed to load OBJ model.");
         return -1;
     }
 
     VertexArrayObject VAO;
-    VAO.bufferVertexData(objLoader.getVertexData(), objLoader.getVertexCount() * sizeof(float) * 8);
-    VAO.bufferElementData(objLoader.getIndexData(), objLoader.getIndexCount() * sizeof(unsigned int));
+    VAO.bufferVertexData(mainObj.getVertexData(), mainObj.getVertexCount() * sizeof(float) * 8);
+    VAO.bufferElementData(mainObj.getIndexData(), mainObj.getIndexCount() * sizeof(unsigned int));
     VAO.setAttributePointer(0, 3, GL_FLOAT, false, 8 * sizeof(float), 0); // position
     VAO.setAttributePointer(1, 3, GL_FLOAT, false, 8 * sizeof(float), 3 * sizeof(float)); // normal
     VAO.setAttributePointer(2, 2, GL_FLOAT, false, 8 * sizeof(float), 6 * sizeof(float)); // texCoord
@@ -40,6 +48,15 @@ int main(int argc, char* argv[]) {
     Texture texture("assets/textures/Sci-fi_Container_Base_Color.png");
     texture.bind(GL_TEXTURE0);
 
+    VertexArrayObject lightCubeVAO;
+    lightCubeVAO.bufferVertexData(lightObj.getVertexData(), lightObj.getVertexCount() * sizeof(float) * 8);
+    lightCubeVAO.bufferElementData(lightObj.getIndexData(), lightObj.getIndexCount() * sizeof(unsigned int));
+    lightCubeVAO.setAttributePointer(0, 3, GL_FLOAT, false, 8 * sizeof(float), 0); // position
+    lightCubeVAO.setAttributePointer(1, 3, GL_FLOAT, false, 8 * sizeof(float), 3 * sizeof(float)); // normal
+    lightCubeVAO.setAttributePointer(2, 2, GL_FLOAT, false, 8 * sizeof(float), 6 * sizeof(float)); // texCoord
+
+    glm::vec3 lightPos(6.0f, 3.0f, 3.0f);
+
     window.setPosition(SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
     window.showWindow();
 
@@ -49,13 +66,28 @@ int main(int argc, char* argv[]) {
         glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-        shader_program.use();
-        shader_program.setMat4("view", camera.getViewMatrix());
-        shader_program.setMat4("projection", camera.getProjectionMatrix());
-        shader_program.setMat4("model", glm::mat4(1.0f));
+        cubeShader.use();
+        cubeShader.setMat4("view", camera.getViewMatrix());
+        cubeShader.setMat4("projection", camera.getProjectionMatrix());
+        cubeShader.setMat4("model", glm::mat4(1.0f));
+        cubeShader.setVec3("objectColor", glm::vec3(1.0f, 0.5f, 0.31f));
+        cubeShader.setVec3("lightColor", glm::vec3(1.0f, 1.0f, 1.0f));
+        cubeShader.setVec3("lightPos", lightPos);
+        cubeShader.setVec3("viewPos", camera.getPosition());
 
         VAO.draw();
 
+        glm::mat4 model = glm::mat4(1.0f);
+        model = glm::translate(model, lightPos);
+        model = glm::scale(model, glm::vec3(0.2f)); 
+
+        lightShader.use();
+        lightShader.setMat4("view", camera.getViewMatrix());
+        lightShader.setMat4("projection", camera.getProjectionMatrix());
+        lightShader.setMat4("model", model);
+
+        lightCubeVAO.draw();
+
         glContext.swapBuffers();
     }