#include <GL/glut.h>
#include <stdio.h>
#include <malloc.h>

GLuint texture;
int ancho = 128;   // imagen en disco
int alto = 128;    // imagen en disco
unsigned char * data;

int LeeImagen()
{
   FILE * file;
   
   file = fopen( "batlogo.raw", "rb" );
   if ( file == NULL ) return 0;
   data = (unsigned char *)malloc(ancho*alto*3);
   fread( data, ancho * alto * 3, 1, file );
   fclose( file );
}
void CargaTextura()				
{				
   glGenTextures(1, &texture);
   glBindTexture(GL_TEXTURE_2D,texture);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, ancho, alto, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR);
}
void dibuja(void) 
{
   glClear(GL_COLOR_BUFFER_BIT);
   glEnable(GL_TEXTURE_2D);
   LeeImagen();
   CargaTextura();
   glBindTexture(GL_TEXTURE_2D,texture);
   glBegin(GL_TRIANGLES);
      glTexCoord2f(0.0,1.0); glVertex2f(-2.0,-2.0); 
      glTexCoord2f(1.0,1.0); glVertex2f(2.0,-2.0);
      glTexCoord2f(0.5,0.0); glVertex2f(0.0,2.0);   
   glEnd();
   glFlush();
}
void reshape(int width,int height) 
{
   glClearColor(0.7,0.7,0.7,0.0);
   glViewport(0,0,width,height);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   gluOrtho2D(-2.5,2.5,-2.5,2.5);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}
void keyboard(unsigned char key,int x,int y)
{
   if (key==27){ 
      glDeleteTextures(1,&texture); 
      exit(0);
   }
}
int main(int argc,char **argv) {
   glutInit(&argc,argv);
   glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE);
   glutInitWindowSize(256,256);
   glutCreateWindow("textura sintética raw");
   glutDisplayFunc(dibuja);
   glutReshapeFunc(reshape);
   glutKeyboardFunc(keyboard); 
   glutMainLoop();
   return 0;
}