Can't load .png image using opengl texture - opengl

Question

#include <stdio.h>
#include <GL/gl.h>
#include <GL/glut.h>
#define KEY_ESCAPE 27
void display();
void keyboard(unsigned char,int,int);
GLuint LoadTextureRAW( const char * filename, int wrap );
int main(int argc, char **argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH );
glutInitWindowSize(600,400);
glutCreateWindow("Opengl Test");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}
void display() {
GLuint texture=LoadTextureRAW("ball.png",1);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,texture);
glBegin( GL_QUADS );
glTexCoord2d(0.0,0.0); glVertex2d(0.0,0.0);
glTexCoord2d(1.0,0.0); glVertex2d(1.0,0.0);
glTexCoord2d(1.0,1.0); glVertex2d(1.0,1.0);
glTexCoord2d(0.0,1.0); glVertex2d(0.0,1.0);
glEnd();
glutSwapBuffers();
}
// load a 256x256 RGB .RAW file as a texture
GLuint LoadTextureRAW( const char * filename, int wrap )
{
GLuint texture;
int width, height;
// BYTE * data;
int *data;
FILE * file;
// open texture data
file = fopen( filename, "rb" );
if ( file == NULL ) return 0;
// allocate buffer
width = 256;
height = 256;
data = (int*)malloc( width * height * 3 );
// read texture data
fread( data, width * height * 3, 1, file );
fclose( file );
// allocate a texture name
glGenTextures( 1, &texture );
// select our current texture
glBindTexture( GL_TEXTURE_2D, texture );
// select modulate to mix texture with color for shading
glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
// when texture area is small, bilinear filter the closest mipmap
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR_MIPMAP_NEAREST );
// when texture area is large, bilinear filter the first mipmap
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
// if wrap is true, the texture wraps over at the edges (repeat)
// ... false, the texture ends at the edges (clamp)
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
wrap ? GL_REPEAT : GL_CLAMP );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
wrap ? GL_REPEAT : GL_CLAMP );
// build our texture mipmaps
gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,
GL_RGB, GL_UNSIGNED_BYTE, data );
// free buffer
free( data );
return texture;
}
void keyboard(unsigned char key, int mousePositionX, int mousePositionY) {
switch ( key ) {
case KEY_ESCAPE:
exit ( 0 );
break;
default:
break;
}
}
I followed this, http://www.nullterminator.net/gltexture.html
What should i do?

Answer 1

"LoadTextureRAW()" is not for PNG files. You will need a third party library like libpng to decode a png file, because they are compressed.
If you don't want to implement libpng yourself, which is kind of advanced, then you can probably find a wrapper library on google somewhere.
You can find a minimal implementation of libpng here:
http://zarb.org/~gc/html/libpng.html