rotating cube

1 files changed, 71 insertions, 17 deletions

diff --git a/src/block.c b/src/block.c
index e93ae6c..3679892 100644
--- a/src/block.c
+++ b/src/block.c
@@ -1,37 +1,62 @@
-#include "cglm/types.h"
+#include "cglm/cglm.h"
+#include "cglm/io.h"
+#include "cglm/util.h"
+#include "math.h"
 #include "glad/glad.h"
 #include "block.h"
+#include "shader.h"
 #include "util.h"
-#include "cglm/cglm.h"
 #include "block.h"
+#include <math.h>
 #include <string.h>
 
 
+#define ARRAY_SIZE(array) (sizeof(array) / sizeof(array[0]))
+
 int block_init(vec3 pos, struct block* blk) {
     // Store buffer data into struct
     // Initialize vbo and ebo for block
     memcpy(blk->coords, pos, sizeof(vec3));
+    // ========== Constants of a block ================
+    // Local world coordinates
     float vertices[] = {
        0.5f,  0.5f,  0.0f, // top-right
        -0.5f, 0.5f,  0.0f, // top-left
        -0.5f, -0.5f,  0.0f, // bottom-left
        0.5f, -0.5f,  0.0f, // bottom-right
+
+       0.5f,  0.5f,  -0.5f, // top-right (back plane)
+       -0.5f, 0.5f,  -0.5f, // top-left (back plane)
+       -0.5f, -0.5f, -0.5f, // bottom-left (back plane)
+       0.5f, -0.5f,  -0.5f, // bottom-right (back plane)
     };
     float colors[] = {
-      1.0f, 0.0f,  0.0f, // r,g,b of first point.
-      0.0f, 1.0f,  0.0f, // r,g,b of second point.
-      0.0f, 0.0f,  1.0f,  // r,g,b of third point.
-      1.0f, 1.0f,  1.0f  // r,g,b of fourth point.
+      1.0f, 0.0f,  0.0f, 
+      1.0f, 0.0f,  0.0f, 
+      0.0f, 1.0f,  0.0f, 
+      0.0f, 1.0f,  0.0f, 
+
+      0.0f, 0.0f,  1.0f, 
+      0.0f, 0.0f,  1.0f, 
+      1.0f, 1.0f,  0.0f, 
+      1.0f, 1.0f,  0.0f, 
+
     };
-    int vertex_order[] = { 1, 2, 3,  3, 0, 1 };
-
-    //TODO:
-    //1. Create VAO for mesh
-    //2. Create VBOs for vertices and colors
-    //3. Set EBO for index order
-    create_vbo(&blk->_vbo1, (void*)vertices, sizeof(float) * 12);
-    create_vbo(&blk->_vbo2, (void*)colors, sizeof(float) * 12);
-    create_ebo(&blk->_ebo, (void*)vertex_order, sizeof(int) * 6);
+    int vertex_order[] = {
+        1, 2, 3,  3, 0, 1, // Front
+        5, 6, 7,  7, 4, 5, // Back
+        0, 3, 7,  7, 4, 0, // Right
+        1, 2, 6,  6, 5, 1, // Left
+        5, 1, 0,  0, 4, 5, // Top
+        6, 2, 3,  3, 7, 6, // Bottom
+    };
+
+    // ================ OpenGL work ================
+    create_vbo(&blk->_vbo1, (void*)vertices, sizeof(float) * ARRAY_SIZE(vertices));
+    create_vbo(&blk->_vbo2, (void*)colors, sizeof(float) * ARRAY_SIZE(colors));
+    create_ebo(&blk->_ebo, (void*)vertex_order, sizeof(int) * ARRAY_SIZE(vertex_order));
+
+    blk->_vertex_count = ARRAY_SIZE(vertex_order);
     glGenVertexArrays(1, &blk->_vao);
     glBindVertexArray(blk->_vao);
     // Enable 2 attribs - position and color
@@ -44,12 +69,41 @@ int block_init(vec3 pos, struct block* blk) {
     glBindBuffer(GL_ARRAY_BUFFER, blk->_vbo2);
     glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, blk->_ebo);
+
     return 0;
 }
 
+void block_update(struct block* blk) {
+    //=============== Matrix Work ==============
+
+    // RTS matrix - rotate, translate, scale
+    glm_mat4_identity(blk->model);
+    float angle = glm_rad(blk->angle);
+    vec3 axis_y = { 0.0f, 1.0f, 0.0f };
+    vec3 pivot = { 0.0f, 0.0f, -0.25f };
+    vec3 translation = { 0.0f, 0, -2.0f };
+    glm_translate(blk->model, translation);
+    glm_rotate_at(blk->model, pivot, angle, axis_y);
+    glm_mat4_print(blk->model, stderr);
+    // View matrix (camera)
+    vec3 camera = { 0.0f, 0.0f, -2.0f };
+    vec3 camera_direction = { 0.0f, 0.0f, 1.0f };
+    glm_look(camera, camera_direction, axis_y, blk->view);
+
+    // Projection (perspective) matrix
+
+    glm_perspective(glm_rad(45.0f), 800.0f / 600.0f, 0.1f, -10.0f, blk->perspective);
+
+    blk->angle = fmodf(blk->angle + 0.01f, 360.0f);
+}
+
 // Register block vbos and ebos to context
-int block_draw(struct block* blk) {
+int block_draw(struct block* blk, struct shader* shader) {
     glBindVertexArray(blk->_vao);
-    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+    set_uniform_mat4("model", shader, blk->model);
+//    set_uniform_mat4("view", shader, blk->view);
+   set_uniform_mat4("perspective", shader, blk->perspective);
+    glDrawElements(GL_TRIANGLES, blk->_vertex_count, GL_UNSIGNED_INT, 0);
+    block_update(blk);
     return 0;
 }