+#ifndef IS_REQUIRED_ROUNDED_CORNER
+#define IS_REQUIRED_ROUNDED_CORNER 0
+#endif
+#ifndef IS_REQUIRED_BORDERLINE
+#define IS_REQUIRED_BORDERLINE 0
+#endif
+#ifndef IS_REQUIRED_BLUR
+#define IS_REQUIRED_BLUR 0
+#endif
+
+#if IS_REQUIRED_ROUNDED_CORNER || IS_REQUIRED_BORDERLINE || IS_REQUIRED_BLUR
+INPUT mediump vec2 vPosition;
+INPUT mediump vec2 vRectSize;
+INPUT mediump vec2 vOptRectSize;
+#if IS_REQUIRED_ROUNDED_CORNER
+INPUT mediump vec4 vCornerRadius;
+#endif
+#endif
+
uniform lowp vec4 uColor;
uniform lowp vec3 mixColor;
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_BORDERLINE
+uniform mediump float borderlineWidth;
+uniform mediump float borderlineOffset;
+uniform lowp vec4 borderlineColor;
+#endif
+#if IS_REQUIRED_BLUR
+uniform mediump float blurRadius;
+#endif
+
+
+#if IS_REQUIRED_ROUNDED_CORNER || IS_REQUIRED_BORDERLINE || IS_REQUIRED_BLUR
+// Global values both rounded corner and borderline use
+
+// radius of rounded corner on this quadrant
+mediump float gRadius = 0.0;
+
+// fragment coordinate. NOTE : vec2(0.0, 0.0) is vRectSize, the corner of visual
+mediump vec2 gFragmentPosition = vec2(0.0, 0.0);
+// center coordinate of rounded corner circle. vec2(gCenterPosition, gCenterPosition).
+mediump float gCenterPosition = 0.0;
+// relative coordinate of gFragmentPosition from gCenterPosition.
+mediump vec2 gDiff = vec2(0.0, 0.0);
+// potential value what our algorithm use.
+mediump float gPotential = 0.0;
+
+// threshold of potential
+mediump float gPotentialRange = 0.0;
+mediump float gMaxOutlinePotential = 0.0;
+mediump float gMinOutlinePotential = 0.0;
+mediump float gMaxInlinePotential = 0.0;
+mediump float gMinInlinePotential = 0.0;
+
+void calculateCornerRadius()
+{
+#if IS_REQUIRED_ROUNDED_CORNER
+ gRadius =
+ mix(
+ mix(vCornerRadius.x, vCornerRadius.y, sign(vPosition.x) * 0.5 + 0.5),
+ mix(vCornerRadius.w, vCornerRadius.z, sign(vPosition.x) * 0.5 + 0.5),
+ sign(vPosition.y) * 0.5 + 0.5
+ );
+#endif
+}
+
+void calculatePosition()
+{
+ gFragmentPosition = abs(vPosition) - vRectSize;
+ gCenterPosition = -gRadius;
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_BORDERLINE
+ gCenterPosition += borderlineWidth * (clamp(borderlineOffset, -1.0, 1.0) + 1.0) * 0.5;
+#endif
+ gDiff = gFragmentPosition - gCenterPosition;
+}
+
+void calculatePotential()
+{
+ gPotential = length(max(gDiff, 0.0)) + min(0.0, max(gDiff.x, gDiff.y));
+}
+
+void setupMinMaxPotential()
+{
+ gPotentialRange = 1.0;
+
+ gMaxOutlinePotential = gRadius + gPotentialRange;
+ gMinOutlinePotential = gRadius - gPotentialRange;
+
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_BORDERLINE
+ gMaxInlinePotential = gMaxOutlinePotential - borderlineWidth;
+ gMinInlinePotential = gMinOutlinePotential - borderlineWidth;
+#else
+ gMaxInlinePotential = gMaxOutlinePotential;
+ gMinInlinePotential = gMinOutlinePotential;
+#endif
+
+ // reduce defect near edge of rounded corner.
+ gMaxOutlinePotential += clamp(-min(gDiff.x, gDiff.y)/ max(1.0, gRadius) , 0.0, 1.0);
+ gMinOutlinePotential += clamp(-min(gDiff.x, gDiff.y)/ max(1.0, gRadius) , 0.0, 1.0);
+}
+
+void PreprocessPotential()
+{
+ calculateCornerRadius();
+ calculatePosition();
+ calculatePotential();
+
+ setupMinMaxPotential();
+}
+#endif
+
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_BORDERLINE
+lowp vec4 convertBorderlineColor(lowp vec4 textureColor)
+{
+ mediump float potential = gPotential;
+
+ // default opacity of borderline is 0.0
+ mediump float borderlineOpacity = 0.0;
+
+ // calculate borderline opacity by potential
+ if(potential > gMinInlinePotential)
+ {
+ // potential is inside borderline range.
+ borderlineOpacity = smoothstep(gMinInlinePotential, gMaxInlinePotential, potential);
+ }
+
+ //calculate inside of borderline when outilneColor.a < 1.0
+ if(borderlineColor.a < 1.0)
+ {
+ mediump float tCornerRadius = -gCenterPosition;
+ mediump float MaxTexturelinePotential = tCornerRadius + gPotentialRange;
+ mediump float MinTexturelinePotential = tCornerRadius - gPotentialRange;
+ if(potential > MaxTexturelinePotential)
+ {
+ // potential is out of texture range. use borderline color instead of texture
+ textureColor = vec4(borderlineColor.xyz, 0.0);
+ }
+ else if(potential > MinTexturelinePotential)
+ {
+ // potential is in texture range
+ textureColor = mix(textureColor, vec4(borderlineColor.xyz, 0.0), smoothstep(MinTexturelinePotential, MaxTexturelinePotential, potential));
+ }
+ borderlineOpacity *= borderlineColor.a;
+ return mix(textureColor, vec4(borderlineColor.xyz, 1.0), borderlineOpacity);
+ }
+ return mix(textureColor, borderlineColor, borderlineOpacity);
+}
+#endif
+
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_ROUNDED_CORNER
+mediump float calculateCornerOpacity()
+{
+ mediump float potential = gPotential;
+
+ // default opacity is 1.0
+ mediump float opacity = 1.0;
+
+ // calculate borderline opacity by potential
+ if(potential > gMaxOutlinePotential)
+ {
+ // potential is out of borderline range. just discard here
+ discard;
+ }
+ else if(potential > gMinOutlinePotential)
+ {
+ opacity = 1.0 - smoothstep(gMinOutlinePotential, gMaxOutlinePotential, potential);
+ }
+ return opacity;
+}
+#endif
+
+#if IS_REQUIRED_BLUR
+mediump float calculateBlurOpacity()
+{
+// Don't use borderline!
+ mediump vec2 v = gDiff;
+ mediump float cy = gRadius + blurRadius;
+ mediump float cr = gRadius + blurRadius;
+
+#if IS_REQUIRED_ROUNDED_CORNER
+ // This routine make perfect circle. If corner radius is not exist, we don't consider prefect circle.
+ cy = min(cy, min(vRectSize.x, vRectSize.y) - gRadius);
+#endif
+ v = vec2(min(v.x, v.y), max(v.x, v.y));
+ v = v + cy;
+
+ mediump float potential = 0.0;
+ mediump float alias = min(gRadius, 1.0);
+ mediump float potentialMin = cy + gRadius - blurRadius - alias;
+ mediump float potentialMax = cy + gRadius + blurRadius + alias;
+
+ // move center of circles for reduce defact
+ mediump float cyDiff = min(cy, 0.2 * blurRadius);
+ cy -= cyDiff;
+ cr += cyDiff;
+
+ mediump float diffFromBaseline = cy * v.y - (cy + cr) * v.x;
+
+ if(diffFromBaseline > 0.0)
+ {
+ // out of calculation bound.
+ potential = v.y;
+
+ // for anti-alias when blurRaidus = 0.0
+ mediump float heuristicBaselineScale = max(1.0 , cr * (cr + cy));
+ mediump float potentialDiff = min(alias, diffFromBaseline / heuristicBaselineScale);
+ potentialMin += potentialDiff;
+ potentialMax -= potentialDiff;
+ }
+ else
+ {
+ // get some circle centered (x, x) and radius (r = cr / cy * x)
+ // s.t. point v is on that circle
+ // highest point of that circle is (x, x + r) and potential is x + r
+
+ // solve (v.x - x)^2 + (v.y - x)^2 = (cr / cy * x)^2
+#if IS_REQUIRED_ROUNDED_CORNER
+ // NOTE : lowspec HW cannot calculate here. need to reduce numeric error
+ mediump float A = (cr * cr - 2.0 * cy * cy);
+ mediump float B = cy * (v.x + v.y);
+ mediump float V = dot(v,v);
+ mediump float D = B * B + A * V;
+ potential = V * (cr + cy) / (sqrt(D) + B);
+#else
+ // We can simplify this value cause cy = 0.8 * blurRadius, cr = 1.2 * blurRadius
+ // potential = 5.0*(sqrt(4.0*(v.x+v.y)^2 + dot(v,v)) - 2.0*(v.x+v.y));
+ // = 10.0*(v.x+v.y) * (sqrt(1.0 + (length(v) / (2.0*(v.x+v.y)))^2) - 1.0);
+ // = 10.0*(v.x+v.y) * (sqrt(1.25 - x + x^2) - 1.0);
+ // ~= 10.0*(v.x+v.y) * (0.11803399 - 0.44721360x + 0.35777088x^2 - 0.14310x^3 + O(x^4)) (Taylor series)
+ // ~= -1.0557281 * (v.x + v.y) + 2.236068 * length(v) - ~~~ (here, x <= 0.5 * (1.0 - sqrt(0.5)) < 0.1464467)
+ // Note : This simplify need cause we should use it on lowspec HW.
+ mediump float x = 0.5 * (1.0 - length(v) / (v.x + v.y));
+ potential = -1.0557281 * (v.x + v.y) + 2.236068 * length(v) + 10.0 * (v.x + v.y) * (0.35777088 - 0.14310 * x) * x * x;
+#endif
+ }
+
+ return 1.0 - smoothstep(potentialMin, potentialMax, potential);
+}
+#endif
void main()
{
- OUT_COLOR = vec4(mixColor, 1.0) * uColor;
-}
\ No newline at end of file
+ lowp vec4 targetColor = vec4(mixColor, 1.0);
+
+#if IS_REQUIRED_BLUR || IS_REQUIRED_ROUNDED_CORNER || IS_REQUIRED_BORDERLINE
+ // skip most potential calculate for performance
+ if(abs(vPosition.x) < vOptRectSize.x && abs(vPosition.y) < vOptRectSize.y)
+ {
+ OUT_COLOR = targetColor * uColor;
+ return;
+ }
+ PreprocessPotential();
+#endif
+
+#if !IS_REQUIRED_BLUR && IS_REQUIRED_BORDERLINE
+ targetColor = convertBorderlineColor(targetColor);
+#endif
+ OUT_COLOR = targetColor * uColor;
+
+#if IS_REQUIRED_BLUR
+ mediump float opacity = calculateBlurOpacity();
+ OUT_COLOR.a *= opacity;
+#elif IS_REQUIRED_ROUNDED_CORNER
+ mediump float opacity = calculateCornerOpacity();
+ OUT_COLOR.a *= opacity;
+#endif
+}