gtk/gsk/ngl/resources/repeat.glsl
Matthias Clasen 06d5c8e72d ngl: Set color as vertex attribute
Instead of using uniforms for color used in multiple
programs, pass it as vertex attributes. This will let
us batch more draw calls, since we don't have to change
uniforms so often. In particular, for syntax-highlighted
text.
2021-03-12 13:18:47 -05:00

42 lines
1.0 KiB
GLSL

// VERTEX_SHADER:
void main() {
gl_Position = u_projection * u_modelview * vec4(aPosition, 0.0, 1.0);
vUv = vec2(aUv.x, aUv.y);
}
// FRAGMENT_SHADER:
uniform vec4 u_child_bounds;
uniform vec4 u_texture_rect;
float wrap(float f, float wrap_for) {
return mod(f, wrap_for);
}
/* We get the texture coordinates via vUv,
* but that might be on a texture atlas, so we need to do the
* wrapping ourselves.
*/
void main() {
/* We map the texture coordinate to [1;0], then wrap it and scale the result again */
float tw = u_texture_rect.z - u_texture_rect.x;
float th = u_texture_rect.w - u_texture_rect.y;
float mapped_x = (vUv.x - u_texture_rect.x) / tw;
float mapped_y = (vUv.y - u_texture_rect.y) / th;
float wrapped_x = wrap(u_child_bounds.x + mapped_x * u_child_bounds.z, 1.0);
float wrapped_y = wrap(u_child_bounds.y + mapped_y * u_child_bounds.w, 1.0);
vec2 tp;
tp.x = u_texture_rect.x + (wrapped_x * tw);
tp.y = u_texture_rect.y + (wrapped_y * th);
vec4 diffuse = GskTexture(u_source, tp);
gskSetOutputColor(diffuse * u_alpha);
}