gtk2/gsk/gl/resources/radial_gradient.glsl
Benjamin Otte ade7509b97 GL renderer: Remove noperspective usage
It causes issues with compilation of GLES shaders and isn't in any
way correct.
2021-11-30 14:12:10 +01:00

88 lines
2.0 KiB
GLSL

// VERTEX_SHADER
// radial_gradient.glsl
uniform vec4 u_geometry;
_OUT_ vec2 coord;
void main() {
gl_Position = u_projection * (u_modelview * vec4(aPosition, 0.0, 1.0));
vec2 mv0 = u_modelview[0].xy;
vec2 mv1 = u_modelview[1].xy;
vec2 offset = aPosition - u_geometry.xy;
vec2 dir = vec2(dot(mv0, offset),
dot(mv1, offset));
coord = dir * u_geometry.zw;
}
// FRAGMENT_SHADER:
// radial_gradient.glsl
#define MAX_COLOR_STOPS 6
#ifdef GSK_LEGACY
uniform int u_num_color_stops;
#else
uniform highp int u_num_color_stops;
#endif
uniform bool u_repeat;
uniform vec2 u_range;
uniform float u_color_stops[MAX_COLOR_STOPS * 5];
_IN_ vec2 coord;
float get_offset(int index) {
// u_color_stops[5 * index] makes Intel Windows driver crash.
// See https://gitlab.gnome.org/GNOME/gtk/-/issues/3783
int base = 5 * index;
return u_color_stops[base];
}
vec4 get_color(int index) {
int base = 5 * index + 1;
return vec4(u_color_stops[base],
u_color_stops[base + 1],
u_color_stops[base + 2],
u_color_stops[base + 3]);
}
void main() {
// Reverse scale
float offset = length(coord) * u_range.x + u_range.y;
float curr_offset;
float next_offset;
if (u_repeat) {
offset = fract(offset);
}
next_offset = get_offset(0);
if (offset < next_offset) {
gskSetOutputColor(gsk_scaled_premultiply(get_color(0), u_alpha));
return;
}
if (offset >= get_offset(u_num_color_stops - 1)) {
gskSetOutputColor(gsk_scaled_premultiply(get_color(u_num_color_stops - 1), u_alpha));
return;
}
for (int i = 0; i < MAX_COLOR_STOPS; i++) {
curr_offset = next_offset;
next_offset = get_offset(i + 1);
if (offset < next_offset) {
float f = (offset - curr_offset) / (next_offset - curr_offset);
vec4 curr_color = gsk_premultiply(get_color(i));
vec4 next_color = gsk_premultiply(get_color(i + 1));
vec4 color = mix(curr_color, next_color, f);
gskSetScaledOutputColor(color, u_alpha);
return;
}
}
}