blob: 2f78d285c96044a5afc75021a83228e14185787a [file] [log] [blame]
#version 100
precision mediump float;
uniform sampler2D uSampler0_Stage0;
uniform vec2 uscale_Stage1;
uniform vec4 uellipse_Stage1;
uniform float uRTHeight;
varying vec4 vColor;
varying vec2 vMatrixCoord_Stage0;
void main() {
vec4 fragCoordYDown =
vec4(gl_FragCoord.x, uRTHeight - gl_FragCoord.y, 1.0, 1.0);
vec4 output_Stage0;
{
// Stage 0: Texture
output_Stage0 = (vColor * texture2D(uSampler0_Stage0, vMatrixCoord_Stage0));
}
vec4 output_Stage1;
{
// Stage 1: Ellipse
vec2 d = fragCoordYDown.xy - uellipse_Stage1.xy;
d *= uscale_Stage1.y;
vec2 Z = d * uellipse_Stage1.zw;
float implicit = dot(Z, d) - 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_Stage1.x;
float alpha = clamp(0.5 - approx_dist, 0.0, 1.0);
output_Stage1 = (output_Stage0 * alpha);
}
gl_FragColor = output_Stage1;
}