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/*
THIS WORK, INCLUDING THE SOURCE CODE, DOCUMENTATION
AND RELATED MEDIA AND DATA, IS PLACED INTO THE PUBLIC DOMAIN.
THE ORIGINAL AUTHOR IS KYLE FOLEY.
THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY
OF ANY KIND, NOT EVEN THE IMPLIED WARRANTY OF
MERCHANTABILITY. THE AUTHOR OF THIS SOFTWARE,
ASSUMES _NO_ RESPONSIBILITY FOR ANY CONSEQUENCE
RESULTING FROM THE USE, MODIFICATION, OR
REDISTRIBUTION OF THIS SOFTWARE.
*/
#ifndef __EMSCRIPTEN__
#define USE_GLEW 1
#endif
#if USE_GLEW
#include "GL/glew.h"
#endif
#include "SDL/SDL.h"
#if !USE_GLEW
#include "SDL/SDL_opengl.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
void verify() {
int width = 640, height = 480;
unsigned char *data = (unsigned char*)malloc(width*height*4);
glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
int sum = 0;
for (int x = 0; x < width*height*4; x++) {
if (x % 4 != 3) sum += x * data[x];
}
#ifdef __EMSCRIPTEN__
int result = sum;
REPORT_RESULT();
#endif
}
int main(int argc, char *argv[])
{
SDL_Surface *screen;
if ( SDL_Init(SDL_INIT_VIDEO) != 0 ) {
printf("Unable to initialize SDL: %s\n", SDL_GetError());
return 1;
}
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
screen = SDL_SetVideoMode( 640, 480, 24, SDL_OPENGL );
if ( !screen ) {
printf("Unable to set video mode: %s\n", SDL_GetError());
return 1;
}
// Create a texture
GLuint texture;
glGenTextures( 1, &texture );
glBindTexture( GL_TEXTURE_2D, texture );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
GLubyte textureData[] = { 0x7f, 0, 0,
0, 0xff, 0,
0x7f, 0, 0,
0, 0xff, 0};
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, 2, 2, 0,
GL_RGB, GL_UNSIGNED_BYTE, textureData );
// BEGIN
#if USE_GLEW
glewInit();
#endif
glClearColor( 0, 0, 0.5, 1.0 );
glClear( GL_COLOR_BUFFER_BIT );
glColor4f(0.8, 0.8, 0.8, 1);
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glEnable(GL_TEXTURE_2D);
glDisable(GL_BLEND);
const int kRowSize = 20;
GLuint buffer;
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
float fbuf[] = {0, 1, 0, 0, 1,
1, 1, 0, 1, 1,
1, 0, 0, 1, 0,
0, 1, 0, 0, 1,
1, 0, 0, 1, 0,
0, 0, 0, 0, 0};
glBufferData(GL_ARRAY_BUFFER, sizeof(fbuf) * sizeof(float), fbuf, GL_STATIC_DRAW);
glTexCoordPointer(2, GL_FLOAT, kRowSize, (GLvoid*)(3*4));
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, kRowSize, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glDrawArrays(GL_TRIANGLES, 0, 6);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
// END
SDL_GL_SwapBuffers();
verify();
#ifndef __EMSCRIPTEN__
SDL_Delay(1500);
#endif
SDL_Quit();
return 0;
}
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