Brickout Invaders Astroids Information
By Kion Nov. 14, 2017
View Source On Github

If you noticed any problems with black being drawn on top of sprites, that is because transparent fragments aren't being discarded. This step is just a quick change to the fragment shader to fix this problem.

#version 120

varying vec2 texcoord;
uniform sampler2D mytexture;

void main(void) {

    vec2 flipped_texcoord = vec2(texcoord.x, 1.0 - texcoord.y);
    vec4 frag = texture2D(mytexture, flipped_texcoord);
    if(frag.z == 0) {
    gl_FragColor = frag;


Since our shader code is compiled by our program, there's no need to recompile. But just to have as a reference, compile command is below.

$ gcc -c -o DashGL/dashgl.o DashGL/dashgl.c -lepoxy -lpng -lm
$ gcc `pkg-config --cflags gtk+-3.0` main.c DashGL/dashgl.o `pkg-config --libs gtk+-3.0` \
-lepoxy -lm -lpng

Run with:

$ ./a.out