Add basic transformation matrix

shaders/vert.glsl

@@ -4,11 +4,13 @@ layout(location=0) in vec3 position;
 layout(location=1) in vec3 color;
 layout(location=2) in vec2 uv;
 
+uniform mat4 matrix;
+
 out vec3 vert_color;
 out vec2 tex_coords;
 
 void main() {
   tex_coords  = uv;
   vert_color  = color;
-  gl_Position = vec4(position, 1.0);
+  gl_Position = matrix * vec4(position, 1.0);
 };

src/main.cc

@@ -175,6 +175,12 @@ int main() {
 
   float texture_mix_factor = 0.2f;
 
+  glm::mat4 mat = glm::mat4(1.0f);
+  mat = glm::rotate(mat, glm::radians(90.0f), glm::vec3(0.0f, 0.0f, 1.0f));
+  mat = glm::scale(mat, glm::vec3(0.5f, 0.5f, 0.5f));
+
+  glUniformMatrix4fv(glGetUniformLocation(main_shader.program, "matrix"), 1, GL_FALSE, glm::value_ptr(mat));
+
   bool running = true;
   SDL_Event event = {};
   while (running) {