intro.cpp

#define WIN32_LEAN_AND_MEAN
#define WIN32_EXTRA_LEAN

#include <windows.h>
#include <mmsystem.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glu.h>
#include <math.h>
#include <stdio.h>
#include "shader.h"
#include "glext.h"

#define DEBUG 1
#define XRES 1024
#define YRES 720
#define FULLSCREEN 0
#define X 0
#define Y 1

PFNGLCREATEPROGRAMPROC glCreateProgram = NULL;
PFNGLCREATESHADERPROC glCreateShader = NULL;
PFNGLSHADERSOURCEPROC glShaderSource = NULL;
PFNGLCOMPILESHADERPROC glCompileShader = NULL;
PFNGLATTACHSHADERPROC glAttachShader = NULL;
PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog = NULL;
PFNGLLINKPROGRAMPROC glLinkProgram = NULL;
PFNGLUSEPROGRAMPROC glUseProgram = NULL;
PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation = NULL;
PFNGLUNIFORM1FPROC glUniform1f = NULL;
PFNGLUNIFORM2FPROC glUniform2f = NULL;
PFNGLUNIFORM3FPROC glUniform3f = NULL;
PFNGLUNIFORM1DPROC glUniform1d = NULL;
PFNGLUNIFORM2DPROC glUniform2d = NULL;
PFNGLUNIFORM1IPROC glUniform1i = NULL;
PFNGLUNIFORM3FVPROC glUniform3fv = NULL;
PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog = NULL;
PFNGLGENFRAMEBUFFERSPROC glGenFramebuffers = NULL;
PFNGLDELETEFRAMEBUFFERSPROC glDeleteFramebuffers = NULL;
PFNGLBINDFRAMEBUFFERPROC glBindFramebuffer = NULL;
PFNGLGENRENDERBUFFERSPROC glGenRenderbuffers = NULL;
PFNGLDELETERENDERBUFFERSPROC glDeleteRenderbuffers = NULL;
PFNGLBINDRENDERBUFFERPROC glBindRenderbuffer = NULL;
PFNGLBLITFRAMEBUFFERPROC glBlitFramebuffer = NULL;
PFNGLRENDERBUFFERSTORAGEPROC glRenderbufferStorage = NULL;
PFNGLFRAMEBUFFERRENDERBUFFERPROC glFramebufferRenderbuffer = NULL;
PFNGLFRAMEBUFFERTEXTURE2DPROC glFramebufferTexture2D = NULL;

static const PIXELFORMATDESCRIPTOR pfd = {
  sizeof(PIXELFORMATDESCRIPTOR),1,PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|PFD_DOUBLEBUFFER,PFD_TYPE_RGBA,
  32,0,0,0,0,0,0,8,0,0,0,0,0,0,32,0,0,PFD_MAIN_PLANE,0,0,0,0
};

static DEVMODE screenSettings = {
  {0},
  0,0,156,0,0x001c0000,{0},0,0,0,0,0,{0},0,32,XRES,YRES,{0},0,
  0,0,0,0,0,0,
  0,0
};

static int glsl_program;
static int frag_shader;
static int last_frame = 0;
static int frame_count = 0;
static long t_last = 0;
static long frame_ticker = 0;
static float R = (float)XRES/YRES;
static GLuint fbo;
static GLuint rb;
static GLuint tex;

void bind_gl_extensions()
{
  glCreateProgram = (PFNGLCREATEPROGRAMPROC)wglGetProcAddress("glCreateProgram");
  glCreateShader = (PFNGLCREATESHADERPROC)wglGetProcAddress("glCreateShader");
  glShaderSource = (PFNGLSHADERSOURCEPROC)wglGetProcAddress("glShaderSource");
  glCompileShader = (PFNGLCOMPILESHADERPROC)wglGetProcAddress("glCompileShader");
  glAttachShader = (PFNGLATTACHSHADERPROC)wglGetProcAddress("glAttachShader");
  glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)wglGetProcAddress("glGetShaderInfoLog");
  glLinkProgram = (PFNGLLINKPROGRAMPROC)wglGetProcAddress("glLinkProgram");
  glUseProgram = (PFNGLUSEPROGRAMPROC)wglGetProcAddress("glUseProgram");
  glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)wglGetProcAddress("glGetUniformLocation");
  glUniform1f = (PFNGLUNIFORM1FPROC)wglGetProcAddress("glUniform1f");
  glUniform2f = (PFNGLUNIFORM2FPROC)wglGetProcAddress("glUniform2f");
  glUniform3f = (PFNGLUNIFORM3FPROC)wglGetProcAddress("glUniform3f");
  glUniform1d = (PFNGLUNIFORM1DPROC)wglGetProcAddress("glUniform1d");
  glUniform2d = (PFNGLUNIFORM2DPROC)wglGetProcAddress("glUniform2d");
  glUniform1i = (PFNGLUNIFORM1IPROC)wglGetProcAddress("glUniform1i");
  glUniform3fv = (PFNGLUNIFORM3FVPROC)wglGetProcAddress("glUniform3fv");
  glGetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC)wglGetProcAddress("glGetProgramInfoLog");
  glGenFramebuffers = (PFNGLGENFRAMEBUFFERSPROC)wglGetProcAddress("glGenFramebuffers");
  glDeleteFramebuffers = (PFNGLDELETEFRAMEBUFFERSPROC)wglGetProcAddress("glDeleteFramebuffers");
  glBindFramebuffer = (PFNGLBINDFRAMEBUFFERPROC)wglGetProcAddress("glBindFramebuffer");
  glGenRenderbuffers = (PFNGLGENRENDERBUFFERSPROC)wglGetProcAddress("glGenRenderbuffers");
  glDeleteRenderbuffers = (PFNGLDELETERENDERBUFFERSPROC)wglGetProcAddress("glDeleteRenderbuffers");
  glBindRenderbuffer = (PFNGLBINDRENDERBUFFERPROC)wglGetProcAddress("glBindRenderbuffer");
  glBlitFramebuffer = (PFNGLBLITFRAMEBUFFERPROC)wglGetProcAddress("glBlitFramebuffer");
  glRenderbufferStorage = (PFNGLRENDERBUFFERSTORAGEPROC)wglGetProcAddress("glRenderbufferStorage");
  glFramebufferRenderbuffer = (PFNGLFRAMEBUFFERRENDERBUFFERPROC)wglGetProcAddress("glFramebufferRenderbuffer");
  glFramebufferTexture2D = (PFNGLFRAMEBUFFERTEXTURE2DPROC)wglGetProcAddress("glFramebufferTexture2D");
}

void draw_scene(float tf, float dtf)
{
  glBindFramebuffer(GL_FRAMEBUFFER,fbo);
  glDrawBuffer(GL_COLOR_ATTACHMENT0);
  glViewport(0,0,XRES/2,YRES/2);
  glClearColor(0.0f,0.0f,0.0f,1.0f);

  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glUniform1f(glGetUniformLocation(glsl_program,"t"),tf);
  glBegin(GL_QUADS);
  glTexCoord2f(-R,-1.0f);
  glVertex2f(-1.0f,-1.0f);
  glTexCoord2f(R,-1.0f);
  glVertex2f(1.0f,-1.0f);
  glTexCoord2f(R,1.0f);
  glVertex2f(1.0f,1.0f);
  glTexCoord2f(-R,1.0f);
  glVertex2f(-1.0f,1.0f);
  glEnd();


}

void setup_gl(void)
{
  glViewport(0,0,XRES,YRES);
  glLoadIdentity();
  glsl_program = glCreateProgram();
  frag_shader = glCreateShader(GL_FRAGMENT_SHADER);
  glShaderSource(frag_shader,1,&fs,0);
  glCompileShader(frag_shader);
  glAttachShader(glsl_program,frag_shader);
  glLinkProgram(glsl_program);
  glUseProgram(glsl_program);
  char log[2048] = {0};
  glGetShaderInfoLog(frag_shader,sizeof(log),0,log);
#if DEBUG
  printf("glsl program log:\n%s\n",log);
#endif
  glGenRenderbuffers(1,&rb);
  glBindRenderbuffer(GL_RENDERBUFFER,rb);
  glGenFramebuffers(1,&fbo);
  glBindFramebuffer(GL_FRAMEBUFFER,fbo);
  glRenderbufferStorage(GL_RENDERBUFFER,GL_DEPTH_COMPONENT,XRES/2,YRES/2);
  glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_DEPTH_ATTACHMENT,GL_RENDERBUFFER,rb);
  glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void main ()
{
  long t_init = timeGetTime();
  long t, dt;
  float tf, dtf;
  t_last = t_init;
#if FULLSCREEN
  if(ChangeDisplaySettings(&screenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL) return;
  HWND hWnd = CreateWindow("static",0,WS_VISIBLE|WS_POPUPWINDOW|WS_MAXIMIZE,0,0,XRES,YRES,0,0,0,0);
#else
  int x = GetSystemMetrics(SM_CXSCREEN);
  int y = GetSystemMetrics(SM_CYSCREEN);
  ShowCursor(0);
  HWND hWnd = CreateWindow("static",0,WS_VISIBLE|WS_POPUPWINDOW|WS_BORDER,(x-XRES)/2,(y-YRES)/2,XRES,YRES,0,0,0,0);
#endif
  if(!hWnd)return;
  HDC hDC = GetDC(hWnd);
  if(!SetPixelFormat(hDC,ChoosePixelFormat(hDC,&pfd),&pfd))return;
  wglMakeCurrent(hDC,wglCreateContext(hDC));
  bind_gl_extensions();
  setup_gl();
  do
  {
    t = timeGetTime();
    dt = t-t_last;
    t_last = t;
    tf = (float)(t-t_init)/1000.0f;
    dtf = (float)dt/1000.0f;
    draw_scene(tf, dtf);
    wglSwapLayerBuffers(hDC,WGL_SWAP_MAIN_PLANE);
    frame_count++;
    if(t>frame_ticker+1000)
    {
#if DEBUG
      printf("fps=%d\n",frame_count);
#endif
      frame_ticker = t;
      frame_count = 0;
    }
  }while(!GetAsyncKeyState(VK_ESCAPE));
  glDeleteFramebuffers(1,&fbo);
  glDeleteRenderbuffers(1,&rb);
  ExitProcess(0);
}