plgl_minimal_example.c

/*
 * This file is part of the "plgl" project
 * (c) 2014 Paul Asmuth <paul@paulasmuth.com>
 *
 * All rights reserved. Please contact me to obtain a license.
 */
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <plgl/engine.h>
#include <plgl/camera.h>
#include <plgl/mesh.h>
#include <plgl/shader.h>
#include <plgl/vmath.h>

/**
 * Minimal plgl engine example. Open a window and draw a rotating teapot with
 * the debug shader.
 */
int main(int argc, char** argv) {
  double    dt;
  engine_t  engine;
  entity_t* teapot;
  mesh_t    teapot_mesh;
  camera_t  camera;

  /* initialize the engine */
  engine_init(&engine);

  if (engine_start(&engine)) {
    goto exit;
  }

  /* initialize the teapot mesh (use DEBUG shader) */
  mesh_init(&teapot_mesh);
  mesh_mkteapot(&teapot_mesh);
  mesh_setshader(&teapot_mesh, engine.shaders[SHADER_DEFAULT_DEBUG]);

  /* intialize the teapot entity */
  entity_init(&teapot);
  entity_setmesh(teapot, &teapot_mesh);

  /* setup our camera */
  camera_init(&camera);
  camera.w_pos.d[0] = 0.0f;
  camera.w_pos.d[1] = -25.0f;
  camera.w_pos.d[2] = -27.0f;
  camera.rot.d[1]   = 0.7f;
  camera_mkview(&camera);

  /* fixpaul remove me */
  glUseProgram(engine.shaders[SHADER_DEFAULT_DEBUG]);
  glUniformMatrix4fv(glGetUniformLocation(engine.shaders[SHADER_DEFAULT_DEBUG], "proj"), 1, GL_FALSE, (const float *) &camera.m_proj);
  glUniformMatrix4fv(glGetUniformLocation(engine.shaders[SHADER_DEFAULT_DEBUG], "view"), 1, GL_FALSE, (const float *) &camera.m_view);

  /* game loop */
  for (;;) {
    /**
     * engine_tick must be called at the beginnning of the game
     * loop and returns the delta time since the last frame.
     */
    dt = engine_tick(&engine);

    /* rotate the teapot a bit */
    teapot->rot.d[0] += fmod(1.0f * dt, VMATH_TAU);

    /* clear the screen */
    engine_clearscr(&engine, NULL);

    /* draw the teapot */
    mesh_draw_entity(teapot);

    /* swap the buffers */
    engine_swapscr(&engine);
  }

exit:

  engine_stop(&engine);
  return 0;
}