Rotating box example

2 files changed, 147 insertions, 9 deletions

diff --git a/src/engine.c b/src/engine.c
index 98395db..cb74e4e 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -10,6 +10,8 @@
 #undef GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
 
+#include <cglm/cglm.h>
+
 #if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
 /* include winapi */
 #include <Windows.h>
@@ -313,7 +315,6 @@ struct glfw_ctx initialize_GLFW(
   GladGLContext *ctx = create_context(window);
   //printf("GL %d.%d\n", GLAD_VERSION_MAJOR(version), GLAD_VERSION_MINOR(version));
 
-
   //ctx->Viewport(0, 0, 200, 200);
 
   if (ctx == NULL) {
@@ -321,12 +322,17 @@ struct glfw_ctx initialize_GLFW(
     exit(EXIT_FAILURE);
   }
 
+  glfwSetFramebufferSizeCallback(window, window_size_callback);
+
 #ifdef _DEBUG
   ctx->ClearColor((float)0x10 / 255.f, (float)0x0a / 255.f, (float)0x33 / 255.f, 0.f);
 #else
   ctx->ClearColor(0x0, 0x0, 0x0, 0.f);
 #endif
 
+  ctx->Enable(GL_DEPTH_TEST);
+  ctx->DepthFunc(GL_LESS);
+
   return (struct glfw_ctx){.w = window, .c = ctx};
 }
 
@@ -392,21 +398,99 @@ Platform* engine_init(const char* windowtitle, v2_i32 windowsize,
   testobject->g_vertex_buffer_data[8] =  0.0f;
 
   static const float bufdata[] = {
-    -1.0f, -1.0f, 0.0f,
-    1.0f, -1.0f, 0.0f,
-    0.0f,  1.0f, 0.0f,
+    -1.0f,-1.0f,-1.0f, // triangle 1 : begin
+    -1.0f,-1.0f, 1.0f,
+    -1.0f, 1.0f, 1.0f, // triangle 1 : end
+    1.0f, 1.0f,-1.0f, // triangle 2 : begin
+    -1.0f,-1.0f,-1.0f,
+    -1.0f, 1.0f,-1.0f, // triangle 2 : end
+    1.0f,-1.0f, 1.0f,
+    -1.0f,-1.0f,-1.0f,
+    1.0f,-1.0f,-1.0f,
+    1.0f, 1.0f,-1.0f,
+    1.0f,-1.0f,-1.0f,
+    -1.0f,-1.0f,-1.0f,
+    -1.0f,-1.0f,-1.0f,
+    -1.0f, 1.0f, 1.0f,
+    -1.0f, 1.0f,-1.0f,
+    1.0f,-1.0f, 1.0f,
+    -1.0f,-1.0f, 1.0f,
+    -1.0f,-1.0f,-1.0f,
+    -1.0f, 1.0f, 1.0f,
+    -1.0f,-1.0f, 1.0f,
+    1.0f,-1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f,-1.0f,-1.0f,
+    1.0f, 1.0f,-1.0f,
+    1.0f,-1.0f,-1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f,-1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f,-1.0f,
+    -1.0f, 1.0f,-1.0f,
+    1.0f, 1.0f, 1.0f,
+    -1.0f, 1.0f,-1.0f,
+    -1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f,
+    -1.0f, 1.0f, 1.0f,
+    1.0f,-1.0f, 1.0f
   };
 
-  LOG("sizeof(bufdata) = %lu", sizeof(bufdata));
-  LOG("sizeof(g_vertex_buffer_data) = %lu", sizeof(testobject->g_vertex_buffer_data));
+  static const GLfloat g_color_buffer_data[] = {
+    0.583f,  0.771f,  0.014f,
+    0.609f,  0.115f,  0.436f,
+    0.327f,  0.483f,  0.844f,
+    0.822f,  0.569f,  0.201f,
+    0.435f,  0.602f,  0.223f,
+    0.310f,  0.747f,  0.185f,
+    0.597f,  0.770f,  0.761f,
+    0.559f,  0.436f,  0.730f,
+    0.359f,  0.583f,  0.152f,
+    0.483f,  0.596f,  0.789f,
+    0.559f,  0.861f,  0.639f,
+    0.195f,  0.548f,  0.859f,
+    0.014f,  0.184f,  0.576f,
+    0.771f,  0.328f,  0.970f,
+    0.406f,  0.615f,  0.116f,
+    0.676f,  0.977f,  0.133f,
+    0.971f,  0.572f,  0.833f,
+    0.140f,  0.616f,  0.489f,
+    0.997f,  0.513f,  0.064f,
+    0.945f,  0.719f,  0.592f,
+    0.543f,  0.021f,  0.978f,
+    0.279f,  0.317f,  0.505f,
+    0.167f,  0.620f,  0.077f,
+    0.347f,  0.857f,  0.137f,
+    0.055f,  0.953f,  0.042f,
+    0.714f,  0.505f,  0.345f,
+    0.783f,  0.290f,  0.734f,
+    0.722f,  0.645f,  0.174f,
+    0.302f,  0.455f,  0.848f,
+    0.225f,  0.587f,  0.040f,
+    0.517f,  0.713f,  0.338f,
+    0.053f,  0.959f,  0.120f,
+    0.393f,  0.621f,  0.362f,
+    0.673f,  0.211f,  0.457f,
+    0.820f,  0.883f,  0.371f,
+    0.982f,  0.099f,  0.879f
+};
+
 
+//  LOG("sizeof(bufdata) = %lu", sizeof(bufdata));
+//  LOG("sizeof(g_vertex_buffer_data) = %lu", sizeof(testobject->g_vertex_buffer_data));
+//
 
   // Generate 1 buffer, put the resulting identifier in vertexbuffer
   gl->GenBuffers(1, &(testobject->vbo));
   // The following commands will talk about our 'vertexbuffer' buffer
   gl->BindBuffer(GL_ARRAY_BUFFER, testobject->vbo);
   // Give our vertices to OpenGL.
-  gl->BufferData(GL_ARRAY_BUFFER, sizeof(float) * 9, testobject->g_vertex_buffer_data, GL_STATIC_DRAW);
+  gl->BufferData(GL_ARRAY_BUFFER, sizeof(bufdata), bufdata, GL_STATIC_DRAW);
+
+  // Same for the color buffer
+  gl->GenBuffers(1, &(testobject->col));
+  gl->BindBuffer(GL_ARRAY_BUFFER, testobject->col);
+  gl->BufferData(GL_ARRAY_BUFFER, sizeof(g_color_buffer_data), g_color_buffer_data, GL_STATIC_DRAW);
 
   testobject->shaderprogram = LoadShaders(gl, "shader.vertexshader", "shader.fragmentshader");
   INFO("Shaderprogram %d", testobject->shaderprogram);
@@ -724,7 +808,36 @@ i32 engine_run(Platform* p, StateType initial_state) {
 //#endif
       render_begin(p->window);
 
+
       gl->UseProgram(p->testobject->shaderprogram);
+
+      {
+        vec3 cam = {4., 3., 3.}; // perspective
+        mat4 per; // perspective
+        mat4 v; // view
+        mat4 model = GLM_MAT4_IDENTITY_INIT;
+        mat4 modelviewprojection;
+
+        f32 ratio = (float)p->window->windowsize.x / (float)p->window->windowsize.y;
+        //glm_perspective(45.f , 600.f / 400.f, 0.1, 100.0f, per);
+        glm_ortho(-10 * ratio, 10 * ratio, -10, 10, -10, 10, per);
+
+        glm_lookat(cam, GLM_VEC3_ZERO, GLM_YUP, v);
+
+        { mat4 t;
+          //modelviewprojection = p * v * model
+          glm_mat4_mul(v, model, t);
+          glm_rotate_at(t, (vec3){0,0,0}, glfwGetTime() / 2.f, (vec3){0,1,0}); //, (vec3)({0,1,0}));
+          glm_mat4_mul(per, t, modelviewprojection);
+        }
+
+        // TODO: Do this only once during initialization
+        u32 matrix = gl->GetUniformLocation(p->testobject->shaderprogram, "MVP");
+
+        gl->UniformMatrix4fv(matrix, 1, GL_FALSE, &modelviewprojection[0][0]);
+      }
+
+
       gl->EnableVertexAttribArray(0);
       gl->BindBuffer(GL_ARRAY_BUFFER, p->testobject->vbo);
       gl->VertexAttribPointer(
@@ -735,11 +848,28 @@ i32 engine_run(Platform* p, StateType initial_state) {
           0,                  // stride
           (void*)0            // array buffer offset
           );
+
+      // Do the color buffer (?)
+      gl->EnableVertexAttribArray(1);
+      gl->BindBuffer(GL_ARRAY_BUFFER, p->testobject->col);
+      gl->VertexAttribPointer(
+          1,                                // attribute. No particular reason for 1, but must match the layout in the shader.
+          3,                                // size
+          GL_FLOAT,                         // type
+          GL_FALSE,                         // normalized?
+          0,                                // stride
+          (void*)0                          // array buffer offset
+          );
+
+
+
+
       gl->UseProgram(p->testobject->shaderprogram);
       // Draw the triangle !
-      gl->DrawArrays(GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
+      gl->DrawArrays(GL_TRIANGLES, 0, 3*12); // Starting from vertex 0; 3 vertices total -> 1 triangle
 
       gl->DisableVertexAttribArray(0);
+      gl->DisableVertexAttribArray(1);
 
       render_present(p->window);
 //    }
diff --git a/src/rendering.c b/src/rendering.c
index 06c14e8..dff3432 100644
--- a/src/rendering.c
+++ b/src/rendering.c
@@ -28,7 +28,7 @@ i32 drawcall_len = 0;
 void render_begin(Window* w) {
   //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glfwMakeContextCurrent(w->window);
-  w->context->Clear(GL_COLOR_BUFFER_BIT);
+  w->context->Clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 }
 
 void render_present(Window* w) {
@@ -69,6 +69,14 @@ void render_present(Window* w) {
 
 void drawcall_reset(void) { drawcall_len = 0; }
 
+void window_size_callback(GLFWwindow* window, int width, int height) {
+  GLOBAL_PLATFORM->window->context->Viewport(0,0, width, height);
+  //*GLOBAL_PLATFORM->window->game_w = width;
+  //*GLOBAL_PLATFORM->window->game_h = height;
+  GLOBAL_PLATFORM->window->windowsize.x = width;
+  GLOBAL_PLATFORM->window->windowsize.y = height;
+}
+
 void engine_window_resize_pointers(i32* w, i32* h) {
   GLOBAL_PLATFORM->window->game_w = w;
   GLOBAL_PLATFORM->window->game_h = h;