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#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 "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,
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, // 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
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
// set vao_buffer to pos buffer obj
glBindBuffer(GL_ARRAY_BUFFER, blk->_vbo1);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
// set vao_buffer to color buffer obj
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, struct shader* shader) {
glBindVertexArray(blk->_vao);
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;
}
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