gtk2/gsk/ngl/resources/preamble.glsl
Matthias Clasen 3252f1e301 gsk: Give ngl its own shader sources
We may want to change the interface between the
shaders and the renderer for ngl, and therefore,
sharing the shaders between gl and ngl will not
be practical, going forward.
2021-03-12 13:18:47 -05:00

58 lines
1.5 KiB
GLSL

#ifndef GSK_LEGACY
precision highp float;
#endif
#if defined(GSK_GLES) || defined(GSK_LEGACY)
#define _OUT_ varying
#define _IN_ varying
#define _NOPERSPECTIVE_
#define _GSK_ROUNDED_RECT_UNIFORM_ vec4[3]
#else
#define _OUT_ out
#define _IN_ in
#define _NOPERSPECTIVE_ noperspective
#define _GSK_ROUNDED_RECT_UNIFORM_ GskRoundedRect
#endif
struct GskRoundedRect
{
vec4 bounds; // Top left and bottom right
// Look, arrays can't be in structs if you want to return the struct
// from a function in gles or whatever. Just kill me.
vec4 corner_points1; // xy = top left, zw = top right
vec4 corner_points2; // xy = bottom right, zw = bottom left
};
// Transform from a C GskRoundedRect to what we need.
GskRoundedRect
gsk_create_rect(vec4[3] data)
{
vec4 bounds = vec4(data[0].xy, data[0].xy + data[0].zw);
vec4 corner_points1 = vec4(bounds.xy + data[1].xy,
bounds.zy + vec2(data[1].zw * vec2(-1, 1)));
vec4 corner_points2 = vec4(bounds.zw + (data[2].xy * vec2(-1, -1)),
bounds.xw + vec2(data[2].zw * vec2(1, -1)));
return GskRoundedRect(bounds, corner_points1, corner_points2);
}
vec4
gsk_get_bounds(vec4[3] data)
{
return vec4(data[0].xy, data[0].xy + data[0].zw);
}
vec4 gsk_premultiply(vec4 c) {
return vec4(c.rgb * c.a, c.a);
}
vec4 gsk_scaled_premultiply(vec4 c, float s) {
// Fast version of gsk_premultiply(c) * s
// 4 muls instead of 7
float a = s * c.a;
return vec4(c.rgb * a, a);
}