gl_context::gl_context(std::string const& name, int width, int height) {
init_glfw();
create_glfw_window(name, width, height);
glfwMakeContextCurrent(_main_window);
TwInit(TW_OPENGL_CORE, nullptr);
TwWindowSize(width, height);
_tweak_bar = TwNewBar("MainBar");
init_glew();
glGenVertexArrays(1, &_vertex_array_id);
glBindVertexArray(_vertex_array_id);
}
int main(int argc, char const *argv[]) {
struct window w;
if(create_glfw_window(&w)) {
return -1;
}
struct file vertex_file;
vertex_file.filename = "shaders/shader.vert";
if(read_file(&vertex_file)) {
return -1;
}
struct file fragment_file;
fragment_file.filename = "shaders/shader.frag";
if(read_file(&fragment_file)) {
return -1;
}
GLuint program = create_gl_program(vertex_file.content, fragment_file.content);
glCallWrapper(glUseProgram(program));
free(vertex_file.content);
free(fragment_file.content);
GLuint vao;
glCallWrapper(glGenVertexArrays(1, &vao));
glCallWrapper(glBindVertexArray(vao));
// Position
glEnableVertexAttribArray(0);
// UV
glEnableVertexAttribArray(3);
GLuint vbo_1;
glCallWrapper(glGenBuffers(1, &vbo_1));
glCallWrapper(glBindBuffer(GL_ARRAY_BUFFER, vbo_1));
GLfloat position[] = {
-0.50, 0.50, 0.00,
0.50, -0.50, 0.00,
-0.50, -0.50, 0.00,
-0.50, 0.50, 0.00,
0.50, 0.50, 0.00,
0.50, -0.50, 0.00,
};
glCallWrapper(glBufferData(GL_ARRAY_BUFFER, sizeof(position), position, GL_DYNAMIC_DRAW));
glCallWrapper(glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL));
mat4 mvp;
cglm_mvp(mvp);
GLuint mvp_id = glGetUniformLocation(program, "mvp");
glCallWrapper(glUniformMatrix4fv(mvp_id, 1, GL_FALSE, &mvp[0][0]));
GLuint vbo_3;
glCallWrapper(glGenBuffers(1, &vbo_3));
glCallWrapper(glBindBuffer(GL_ARRAY_BUFFER, vbo_3));
const GLfloat uvs[] = {
0.00, 0.40,
0.40, 0.00,
0.00, 0.00,
0.00, 0.40,
0.40, 0.40,
0.40, 0.00,
};
glCallWrapper(glBufferData(GL_ARRAY_BUFFER, sizeof(uvs), uvs, GL_DYNAMIC_DRAW));
glCallWrapper(glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, 0, NULL));
struct image img;
img.imagename = "textures/uvtemplate.bmp";
if(read_bmp(&img)) {
return -1;
}
GLuint img_tex;
glCallWrapper(glGenTextures(1, &img_tex));
glCallWrapper(glBindTexture(GL_TEXTURE_2D, img_tex));
glCallWrapper(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, img.width, img.height, 0, GL_RGB, GL_UNSIGNED_BYTE, img.content));
glCallWrapper(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST));
glCallWrapper(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST));
free(img.content);
GLuint img_tex_id = glGetUniformLocation(program, "img_sampler");
glCallWrapper(glUniform1i(img_tex_id, 0 /* Default active texture */));
while(1) {
glCallWrapper(glDrawArrays(GL_TRIANGLES, 0, 6));
glfwSwapBuffers(w.window);
glfwPollEvents();
}
return 0;
}