blob: 740a6ee039b898f260f6fe5cb2f79ef6ac1cb1f0 [file] [log] [blame]
#version 100
precision mediump float;
uniform vec2 uscale_Stage1;
uniform vec4 uellipse_Stage1;
uniform float uRTHeight;
uniform vec2 uscale_Stage2;
uniform vec4 uellipse_Stage2;
varying vec4 vColor;
varying vec2 vEllipseOffsets_Stage0;
varying vec4 vEllipseRadii_Stage0;
void main()
{
vec4 fragCoordYDown = vec4(gl_FragCoord.x, uRTHeight - gl_FragCoord.y, 1.0, 1.0);
vec4 output_Stage0;
{
// Stage 0: EllipseEdge
vec2 scaledOffset = vEllipseOffsets_Stage0*vEllipseRadii_Stage0.xy;
float test = dot(scaledOffset, scaledOffset) - 1.0;
vec2 grad = 2.0*scaledOffset*vEllipseRadii_Stage0.xy;
float grad_dot = dot(grad, grad);
grad_dot = max(grad_dot, 1.0e-4);
float invlen = inversesqrt(grad_dot);
float edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);
output_Stage0 = vec4(edgeAlpha);
}
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);
}
vec4 output_Stage2;
{
// Stage 2: Ellipse
vec2 d = fragCoordYDown.xy - uellipse_Stage2.xy;
d *= uscale_Stage2.y;
vec2 Z = d * uellipse_Stage2.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_Stage2.x;
float alpha = clamp(0.5 - approx_dist, 0.0, 1.0);
output_Stage2 = (output_Stage1 * alpha);
}
gl_FragColor = (vColor * output_Stage2);
}