WIP: essais

opengl_sandbox/main.c

@@ -14,9 +14,9 @@
 GtkWidget *window;
 
 // OpenGL objects
-GLuint vao, vbo, ebo, instance_vbo, arrow_instance_vbo;
+GLuint vao, arrow_vao;
-GLuint arrow_vao, arrow_vbo, arrow_ebo;
+GLuint vbo, arrow_vbo, cubes_instance_vbo, arrow_instance_vbo;
-GLuint edge_ebo;
+GLuint ebo, arrow_ebo, edge_ebo;
 GLuint shader_program;
 unsigned int num_instances = N_INSTANCE;
 mat4 instance_matrices[N_INSTANCE];
@@ -39,9 +39,9 @@ mat4 projection, view;
 // Function Prototypes zone ---------------------------------------------------
 
 GLuint create_shader_program ();
-void setup_buffers ();
+void setup_cubes_buffers ();
 void setup_arrow_buffers ();
-void setup_instance_data ();
+void setup_cube_instance_data ();
 void setup_arrow_instance_data();
 static void on_realize (GtkGLArea *area);
 static gboolean on_render (GtkGLArea *area, GdkGLContext *context);
@@ -253,7 +253,7 @@ GLuint create_shader_program ()
 }
 
 // Setup OpenGL buffers (VBO, VAO, EBO for cubes and edges)
-void setup_buffers ()
+void setup_cubes_buffers ()
 {
     glGenVertexArrays(1, &vao);
     glBindVertexArray(vao);
@@ -280,29 +280,8 @@ void setup_buffers ()
     glBindVertexArray(0);
 }
 
-void setup_arrow_buffers() {
-    glGenVertexArrays(1, &arrow_vao);
-    glBindVertexArray(arrow_vao);
-
-    // Vertex buffer for arrows
-    glGenBuffers(1, &arrow_vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, arrow_vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(arrow_vertices), arrow_vertices, GL_STATIC_DRAW);
-
-    // Index buffer for arrows
-    glGenBuffers(1, &arrow_ebo);
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
-    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(arrow_indices), arrow_indices, GL_STATIC_DRAW);
-
-    // Vertex attributes
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
-    glEnableVertexAttribArray(0);
-
-    glBindVertexArray(0);
-}
-
 // Setup instance data for cubes (random positions)
-void setup_instance_data ()
+void setup_cube_instance_data ()
 {
     g_message("[%s] setting up cube instance data...",
               __func__);
@@ -312,10 +291,10 @@ void setup_instance_data ()
     g_message("[%s] random seed initialized",
               __func__);
 
-    glGenBuffers(1, &instance_vbo);
+    glGenBuffers(1, &cubes_instance_vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, cubes_instance_vbo);
 
-    g_message("[%s] instance_vbo buffer bound",
+    g_message("[%s] cubes_instance_vbo buffer bound",
               __func__);
 
     for (unsigned int i = 0; i < num_instances; i++) {
@@ -330,6 +309,7 @@ void setup_instance_data ()
 
         glm_translate(instance_matrices[i], position);
     }
+
     g_message("[%s] generated %d cube instances",
               __func__,
               num_instances);
@@ -355,7 +335,30 @@ void setup_instance_data ()
               __func__);
 }
 
-void setup_arrow_instance_data() {
+void setup_arrow_buffers()
+{
+    glGenVertexArrays(1, &arrow_vao);
+    glBindVertexArray(arrow_vao);
+
+    // Vertex buffer for arrows
+    glGenBuffers(1, &arrow_vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, arrow_vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(arrow_vertices), arrow_vertices, GL_STATIC_DRAW);
+
+    // Index buffer for arrows
+    glGenBuffers(1, &arrow_ebo);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(arrow_indices), arrow_indices, GL_STATIC_DRAW);
+
+    // Vertex attributes
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    glBindVertexArray(0);
+}
+
+void setup_arrow_instance_data()
+{
     // Define indices for the arrows (lines from center to cube faces)
     GLuint arrow_indices[] = {
         0, 1,  // Arrow pointing to right face
@@ -366,18 +369,12 @@ void setup_arrow_instance_data() {
         0, 6   // Arrow pointing to back face
     };
 
-    // Generate Vertex Array Object for arrows
-    glGenVertexArrays(1, &arrow_vao);
-    glBindVertexArray(arrow_vao);
-
     // Generate Vertex Buffer Object for arrows
-    GLuint arrow_vbo;
     glGenBuffers(1, &arrow_vbo);
     glBindBuffer(GL_ARRAY_BUFFER, arrow_vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(arrow_vertices), arrow_vertices, GL_STATIC_DRAW);
 
     // Generate Element Buffer Object for arrows
-    GLuint arrow_ebo;
     glGenBuffers(1, &arrow_ebo);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(arrow_indices), arrow_indices, GL_STATIC_DRAW);
@@ -436,9 +433,9 @@ static void on_realize(GtkGLArea *area)
 
     // Create shader program and setup buffers
     shader_program = create_shader_program();
-    setup_buffers();
+    setup_cubes_buffers();
     setup_arrow_buffers();
-    setup_instance_data();
+    setup_cube_instance_data();
     setup_arrow_instance_data();  // Setup arrow data
 
     // Set the background color
@@ -475,7 +472,7 @@ static gboolean on_render(GtkGLArea *area, GdkGLContext *context)
     }
 
     // Update the instance matrix buffer with the modified instance matrices
-    glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, cubes_instance_vbo);
     glBufferSubData(GL_ARRAY_BUFFER, 0, num_instances * sizeof(mat4), instance_matrices);
 
     // Draw the cubes with the updated instance matrices
@@ -500,6 +497,7 @@ static gboolean on_render(GtkGLArea *area, GdkGLContext *context)
     glUniformMatrix4fv(viewLoc, 1, GL_FALSE, (const GLfloat *)view);
 
     // Draw the arrows
+    glBindVertexArray(arrow_vao);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
     glDrawElementsInstanced(GL_LINES, 12, GL_UNSIGNED_INT, 0, num_instances);
 
@@ -597,3 +595,4 @@ int main (int argc, char *argv[])
 
     return status;
 }
+