gtk/gsk/gl/resources/preamble.glsl
Matthias Clasen 9fd4feef0c gsk: Use some GLES extensions
Allow our shaders to use samplerExternalOES, by declaring
that we use the relevant extension. Unfortunately, this
only works for gles, and requires different extensions for
gles2 and gles3. Yay
2023-10-22 16:42:17 -04:00

119 lines
2.7 KiB
GLSL

#if defined(GSK_GLES3)
#extension GL_OES_EGL_image_external_essl3 : require
#elif defined (GSK_GLES)
#extension GL_OES_EGL_image_external : require
#endif
#ifndef GSK_LEGACY
precision highp float;
#endif
#if defined(GSK_GLES) || defined(GSK_LEGACY)
#define _OUT_ varying
#define _IN_ varying
#define _GSK_ROUNDED_RECT_UNIFORM_ vec4[3]
#else
#define _OUT_ out
#define _IN_ in
#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
};
void gsk_rounded_rect_normalize(inout GskRoundedRect r)
{
if (r.bounds.x > r.bounds.z)
{
float t = r.bounds.x;
r.bounds.x = r.bounds.z;
r.bounds.z = t;
vec2 c = r.corner_points1.xy;
r.corner_points1.xy = r.corner_points1.zw;
r.corner_points1.zw = c;
c = r.corner_points2.xy;
r.corner_points2.xy = r.corner_points2.zw;
r.corner_points2.zw = c;
}
if (r.bounds.y > r.bounds.w)
{
float t = r.bounds.y;
r.bounds.y = r.bounds.w;
r.bounds.w = t;
vec2 c = r.corner_points1.xy;
r.corner_points1.xy = r.corner_points2.xy;
r.corner_points2.xy = c;
c = r.corner_points1.zw;
r.corner_points1.zw = r.corner_points2.zw;
r.corner_points2.zw = c;
}
}
void gsk_bounds_normalize (inout vec4 bounds)
{
if (bounds.x > bounds.z)
{
float t = bounds.x;
bounds.x = bounds.z;
bounds.z = t;
}
if (bounds.y > bounds.w)
{
float t = bounds.y;
bounds.y = bounds.w;
bounds.w = t;
}
}
// 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)));
GskRoundedRect rect = GskRoundedRect(bounds, corner_points1, corner_points2);
gsk_rounded_rect_normalize (rect);
return rect;
}
vec4
gsk_get_bounds(vec4[3] data)
{
vec4 bounds = vec4(data[0].xy, data[0].xy + data[0].zw);
gsk_bounds_normalize (bounds);
return bounds;
}
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);
}