blob: 0b82ab9efac1e273c2638534d7001f44534e05fa [file] [log] [blame]
#version 100
precision mediump float;
uniform vec4 urect_Stage0;
uniform float uRTHeight;
uniform vec4 urect_Stage1;
uniform vec4 uinnerRect_Stage2;
uniform vec2 uscale_Stage2;
uniform vec2 uinvRadiiXY_Stage2;
varying vec4 vColor;
void main()
{
vec4 fragCoordYDown = vec4(gl_FragCoord.x, uRTHeight - gl_FragCoord.y, 1.0, 1.0);
vec4 output_Stage0;
{
// Stage 0: AARect
float xSub, ySub;
xSub = min(fragCoordYDown.x - urect_Stage0.x, 0.0);
xSub += min(urect_Stage0.z - fragCoordYDown.x, 0.0);
ySub = min(fragCoordYDown.y - urect_Stage0.y, 0.0);
ySub += min(urect_Stage0.w - fragCoordYDown.y, 0.0);
float alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));
alpha = 1.0 - alpha;
output_Stage0 = (vColor * alpha);
}
vec4 output_Stage1;
{
// Stage 1: AARect
float xSub, ySub;
xSub = min(fragCoordYDown.x - urect_Stage1.x, 0.0);
xSub += min(urect_Stage1.z - fragCoordYDown.x, 0.0);
ySub = min(fragCoordYDown.y - urect_Stage1.y, 0.0);
ySub += min(urect_Stage1.w - fragCoordYDown.y, 0.0);
float alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));
output_Stage1 = (output_Stage0 * alpha);
}
vec4 output_Stage2;
{
// Stage 2: EllipticalRRect
vec2 dxy0 = uinnerRect_Stage2.xy - fragCoordYDown.xy;
vec2 dxy1 = fragCoordYDown.xy - uinnerRect_Stage2.zw;
vec2 dxy = max(max(dxy0, dxy1), 0.0);
dxy *= uscale_Stage2.y;
vec2 Z = dxy * uinvRadiiXY_Stage2;
float implicit = dot(Z, dxy) - 1.0;
float grad_dot = 4.0 * dot(Z, Z);
grad_dot = max(grad_dot, 1.0e-4);
float approx_dist = implicit * inversesqrt(grad_dot);
approx_dist *= uscale_Stage2.x;
float alpha = clamp(0.5 - approx_dist, 0.0, 1.0);
output_Stage2 = (output_Stage1 * alpha);
}
gl_FragColor = output_Stage2;
}