#version 100 | |
precision mediump float; | |
uniform vec4 uinnerRect_Stage1; | |
uniform float uRTHeight; | |
uniform vec2 uinvRadiiXY_Stage1; | |
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: EllipticalRRect | |
vec2 dxy0 = uinnerRect_Stage1.xy - fragCoordYDown.xy; | |
vec2 dxy1 = fragCoordYDown.xy - uinnerRect_Stage1.zw; | |
vec2 dxy = max(max(dxy0, dxy1), 0.0); | |
vec2 Z = dxy * uinvRadiiXY_Stage1; | |
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); | |
float alpha = clamp(0.5 + approx_dist, 0.0, 1.0); | |
output_Stage1 = (output_Stage0 * alpha); | |
} | |
gl_FragColor = (vColor * output_Stage1); | |
} |