#include "render.h"

render_t *RENDER_CURRENT = NULL;

render_t * renderInit(int32_t width, int32_t height, char *name) {
  // Can't contextualize twice
  if(RENDER_CURRENT != NULL) return NULL;

  // Attempt to init GLFW
  if(!glfwInit()) return NULL;
 
  // Initialize the renderer
  render_t *render = malloc(sizeof(render_t));
  if(!render) return NULL; 
  render->width = width;
  render->height = height;

  // Create the window.
  render->window = glfwCreateWindow(width, height, name, NULL, NULL);
  if(!render->window) {
    free(render);
    glfwTerminate();
    return NULL;
  }

  // Make the window the context current
  glfwMakeContextCurrent(render->window);
  RENDER_CURRENT = render;

  // Listeners
  glfwSetWindowSizeCallback(render->window, &renderOnResize);

  //GLEnable Things
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glEnable(GL_DEPTH_TEST);
  glDepthMask(GL_TRUE);
  glDepthFunc(GL_LEQUAL);

  return render;
}

void renderFrame(render_t *render) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glBegin(GL_TRIANGLES);
    glColor3f(1, 0, 0);
    glVertex3f(-1, -1, 0);

    glColor3f(0, 1, 0);
    glVertex3f(0, 1, 0);

    glColor3f(0, 0, 1);
    glVertex3f(1, -1, 0);
  glEnd();
}

bool renderDispose(render_t *render) {
  // Cleanup the callback
  glfwSetWindowSizeCallback(render->window, NULL);

  // Free up the renderer
  free(render);
  RENDER_CURRENT = NULL;

  // Terminate the GLFW context.
  glfwTerminate();
  return true;
}

void renderOnResize(GLFWwindow *window, int32_t width, int32_t height) {
  RENDER_CURRENT->width = width;
  RENDER_CURRENT->height = height;
  glViewport(0, 0, width, height);
}