+#if defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE) || defined(IS_REQUIRED_BLUR)
+INPUT mediump vec2 vPosition;
+INPUT mediump vec2 vRectSize;
+INPUT mediump vec2 vOptRectSize;
+#ifdef IS_REQUIRED_ROUNDED_CORNER
+INPUT mediump vec4 vCornerRadius;
+#endif
+#endif
+
uniform lowp vec4 uColor;
uniform lowp vec3 mixColor;
+#ifdef IS_REQUIRED_BLUR
+uniform mediump float blurRadius;
+#elif defined(IS_REQUIRED_BORDERLINE)
+uniform mediump float borderlineWidth;
+uniform mediump float borderlineOffset;
+uniform lowp vec4 borderlineColor;
+uniform lowp vec4 uActorColor;
+#endif
+
+
+#if defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE) || defined(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()
+{
+#ifdef 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;
+#ifdef IS_REQUIRED_BLUR
+#elif defined(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()
+{
+ // Set soft anti-alias range at most 2% of visual size
+ gPotentialRange = min(1.0, max(vRectSize.x, vRectSize.y) * 0.02);
+
+ gMaxOutlinePotential = gRadius + gPotentialRange;
+ gMinOutlinePotential = gRadius - gPotentialRange;
+
+#ifdef IS_REQUIRED_BLUR
+ gMaxInlinePotential = gMaxOutlinePotential;
+ gMinInlinePotential = gMinOutlinePotential;
+#elif defined(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
+
+#ifdef IS_REQUIRED_BLUR
+#elif defined(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);
+
+ // Muliply borderlineWidth to resolve very thin borderline
+ borderlineOpacity *= min(1.0, borderlineWidth / gPotentialRange);
+ }
+
+ lowp vec3 borderlineColorRGB = borderlineColor.rgb * uActorColor.rgb;
+ lowp float borderlineColorAlpha = borderlineColor.a * uActorColor.a;
+ // NOTE : color-visual is always not preMultiplied.
+
+ // Calculate inside of borderline when alpha is between (0.0 1.0). So we need to apply texture color.
+ // If borderlineOpacity is exactly 0.0, we always use whole texture color. In this case, we don't need to run below code.
+ // But if borderlineOpacity > 0.0 and borderlineColor.a == 0.0, we need to apply tCornerRadius.
+ if(borderlineOpacity > 0.0 && borderlineColor.a * borderlineOpacity < 1.0)
+ {
+ mediump float tCornerRadius = -gCenterPosition + gPotentialRange;
+ mediump float MaxTexturelinePotential = tCornerRadius + gPotentialRange;
+ mediump float MinTexturelinePotential = tCornerRadius - gPotentialRange;
+ if(potential > MaxTexturelinePotential)
+ {
+ // potential is out of texture range.
+ textureColor = vec4(0.0);
+ }
+ else
+ {
+ // potential is in texture range.
+ lowp float textureAlphaScale = mix(1.0, 0.0, smoothstep(MinTexturelinePotential, MaxTexturelinePotential, potential));
+ textureColor.a *= textureAlphaScale;
+ textureColor.rgb *= textureColor.a;
+ }
+
+ // NOTE : color-visual is always not preMultiplied.
+ borderlineColorAlpha *= borderlineOpacity;
+ borderlineColorRGB *= borderlineColorAlpha;
+ // We use pre-multiplied color to reduce operations.
+ // In here, textureColor and borderlineColorRGB is pre-multiplied color now.
+
+ // Manual blend operation with premultiplied colors.
+ // Final alpha = borderlineColorAlpha + (1.0 - borderlineColorAlpha) * textureColor.a.
+ // (Final rgb * alpha) = borderlineColorRGB + (1.0 - borderlineColorAlpha) * textureColor.rgb
+ // If preMultipliedAlpha == 1.0, just return vec4(rgb*alpha, alpha)
+ // Else, return vec4((rgb*alpha) / alpha, alpha)
+
+ lowp float finalAlpha = mix(textureColor.a, 1.0, borderlineColorAlpha);
+ lowp vec3 finalMultipliedRGB = borderlineColorRGB + (1.0 - borderlineColorAlpha) * textureColor.rgb;
+ // TODO : Need to find some way without division
+ return vec4(finalMultipliedRGB / finalAlpha, finalAlpha);
+ }
+ return mix(textureColor, vec4(borderlineColorRGB, borderlineColorAlpha), borderlineOpacity);
+}
+#endif
+
+#ifdef IS_REQUIRED_BLUR
+#elif defined(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
+
+#ifdef IS_REQUIRED_BLUR
+mediump float calculateBlurOpacity()
+{
+// Don't use borderline!
+ mediump vec2 v = gDiff;
+ mediump float cy = gRadius + blurRadius;
+ mediump float cr = gRadius + blurRadius;
+
+#ifdef 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
+#ifdef IS_REQUIRED_ROUNDED_CORNER
+ // Note : lowspec HW cannot calculate here. need to reduce numeric error
+ highp float A = (cr * cr - 2.0 * cy * cy);
+ highp float B = cy * (v.x + v.y);
+ highp float V = dot(v,v);
+ highp 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^5)) (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) * uColor;
+
+#if defined(IS_REQUIRED_BLUR) || defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE)
+ // skip most potential calculate for performance
+ if(abs(vPosition.x) < vOptRectSize.x && abs(vPosition.y) < vOptRectSize.y)
+ {
+ OUT_COLOR = targetColor;
+ }
+ else
+ {
+ PreprocessPotential();
+#endif
+
+#ifdef IS_REQUIRED_BLUR
+#elif defined(IS_REQUIRED_BORDERLINE)
+ targetColor = convertBorderlineColor(targetColor);
+#endif
+ OUT_COLOR = targetColor;
+
+#ifdef IS_REQUIRED_BLUR
+ mediump float opacity = calculateBlurOpacity();
+ OUT_COLOR.a *= opacity;
+#elif defined(IS_REQUIRED_ROUNDED_CORNER)
+ mediump float opacity = calculateCornerOpacity();
+ OUT_COLOR.a *= opacity;
+#endif
+
+#if defined(IS_REQUIRED_BLUR) || defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE)
+ }
+#endif
+}