1 #if defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE) || defined(IS_REQUIRED_BLUR)
2 INPUT mediump vec2 vPosition;
3 INPUT mediump vec2 vRectSize;
4 INPUT mediump vec2 vOptRectSize;
5 INPUT mediump float vAliasMargin;
6 #ifdef IS_REQUIRED_ROUNDED_CORNER
7 INPUT mediump vec4 vCornerRadius;
11 uniform lowp vec4 uColor;
12 uniform lowp vec3 mixColor;
13 #ifdef IS_REQUIRED_BLUR
14 uniform mediump float blurRadius;
15 #elif defined(IS_REQUIRED_BORDERLINE)
16 uniform mediump float borderlineWidth;
17 uniform mediump float borderlineOffset;
18 uniform lowp vec4 borderlineColor;
19 uniform lowp vec4 uActorColor;
22 #if defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE) || defined(IS_REQUIRED_BLUR)
23 // Global values both rounded corner and borderline use
25 // radius of rounded corner on this quadrant
26 mediump float gRadius = 0.0;
28 // fragment coordinate. NOTE : vec2(0.0, 0.0) is vRectSize, the corner of visual
29 mediump vec2 gFragmentPosition = vec2(0.0, 0.0);
30 // center coordinate of rounded corner circle. vec2(gCenterPosition, gCenterPosition).
31 mediump float gCenterPosition = 0.0;
32 // relative coordinate of gFragmentPosition from gCenterPosition.
33 mediump vec2 gDiff = vec2(0.0, 0.0);
34 // potential value what our algorithm use.
35 mediump float gPotential = 0.0;
37 // threshold of potential
38 mediump float gPotentialRange = 0.0;
39 mediump float gMaxOutlinePotential = 0.0;
40 mediump float gMinOutlinePotential = 0.0;
41 mediump float gMaxInlinePotential = 0.0;
42 mediump float gMinInlinePotential = 0.0;
44 void calculateCornerRadius()
46 #ifdef IS_REQUIRED_ROUNDED_CORNER
49 mix(vCornerRadius.x, vCornerRadius.y, sign(vPosition.x) * 0.5 + 0.5),
50 mix(vCornerRadius.w, vCornerRadius.z, sign(vPosition.x) * 0.5 + 0.5),
51 sign(vPosition.y) * 0.5 + 0.5
56 void calculatePosition()
58 gFragmentPosition = abs(vPosition) - vRectSize;
59 gCenterPosition = -gRadius;
60 #ifdef IS_REQUIRED_BLUR
61 #elif defined(IS_REQUIRED_BORDERLINE)
62 gCenterPosition += borderlineWidth * (clamp(borderlineOffset, -1.0, 1.0) + 1.0) * 0.5;
64 gDiff = gFragmentPosition - gCenterPosition;
67 void calculatePotential()
69 gPotential = length(max(gDiff, 0.0)) + min(0.0, max(gDiff.x, gDiff.y));
72 void setupMinMaxPotential()
74 gPotentialRange = vAliasMargin;
76 gMaxOutlinePotential = gRadius + gPotentialRange;
77 gMinOutlinePotential = gRadius - gPotentialRange;
79 #ifdef IS_REQUIRED_BLUR
80 gMaxInlinePotential = gMaxOutlinePotential;
81 gMinInlinePotential = gMinOutlinePotential;
82 #elif defined(IS_REQUIRED_BORDERLINE)
83 gMaxInlinePotential = gMaxOutlinePotential - borderlineWidth;
84 gMinInlinePotential = gMinOutlinePotential - borderlineWidth;
86 gMaxInlinePotential = gMaxOutlinePotential;
87 gMinInlinePotential = gMinOutlinePotential;
90 // reduce defect near edge of rounded corner.
91 gMaxOutlinePotential += clamp(-min(gDiff.x, gDiff.y) / max(1.0, gRadius), 0.0, 1.0);
92 gMinOutlinePotential += clamp(-min(gDiff.x, gDiff.y) / max(1.0, gRadius), 0.0, 1.0);
95 void PreprocessPotential()
97 calculateCornerRadius();
101 setupMinMaxPotential();
105 #ifdef IS_REQUIRED_BLUR
106 #elif defined(IS_REQUIRED_BORDERLINE)
107 lowp vec4 convertBorderlineColor(lowp vec4 textureColor)
109 mediump float potential = gPotential;
111 // default opacity of borderline is 0.0
112 mediump float borderlineOpacity = 0.0;
114 // calculate borderline opacity by potential
115 if(potential > gMinInlinePotential)
117 // potential is inside borderline range.
118 borderlineOpacity = smoothstep(gMinInlinePotential, gMaxInlinePotential, potential);
120 // Muliply borderlineWidth to resolve very thin borderline
121 borderlineOpacity *= min(1.0, borderlineWidth / gPotentialRange);
124 lowp vec3 borderlineColorRGB = borderlineColor.rgb * uActorColor.rgb;
125 lowp float borderlineColorAlpha = borderlineColor.a * uActorColor.a;
126 // NOTE : color-visual is always not preMultiplied.
128 // Calculate inside of borderline when alpha is between (0.0 1.0). So we need to apply texture color.
129 // If borderlineOpacity is exactly 0.0, we always use whole texture color. In this case, we don't need to run below code.
130 // But if borderlineOpacity > 0.0 and borderlineColor.a == 0.0, we need to apply tCornerRadius.
131 if(borderlineOpacity > 0.0 && borderlineColor.a * borderlineOpacity < 1.0)
133 mediump float tCornerRadius = -gCenterPosition + gPotentialRange;
134 mediump float MaxTexturelinePotential = tCornerRadius + gPotentialRange;
135 mediump float MinTexturelinePotential = tCornerRadius - gPotentialRange;
136 if(potential > MaxTexturelinePotential)
138 // potential is out of texture range.
139 textureColor = vec4(0.0);
143 // potential is in texture range.
144 lowp float textureAlphaScale = mix(1.0, 0.0, smoothstep(MinTexturelinePotential, MaxTexturelinePotential, potential));
145 textureColor.a *= textureAlphaScale;
146 textureColor.rgb *= textureColor.a;
149 // NOTE : color-visual is always not preMultiplied.
150 borderlineColorAlpha *= borderlineOpacity;
151 borderlineColorRGB *= borderlineColorAlpha;
152 // We use pre-multiplied color to reduce operations.
153 // In here, textureColor and borderlineColorRGB is pre-multiplied color now.
155 // Manual blend operation with premultiplied colors.
156 // Final alpha = borderlineColorAlpha + (1.0 - borderlineColorAlpha) * textureColor.a.
157 // (Final rgb * alpha) = borderlineColorRGB + (1.0 - borderlineColorAlpha) * textureColor.rgb
158 // If preMultipliedAlpha == 1.0, just return vec4(rgb*alpha, alpha)
159 // Else, return vec4((rgb*alpha) / alpha, alpha)
161 lowp float finalAlpha = mix(textureColor.a, 1.0, borderlineColorAlpha);
162 lowp vec3 finalMultipliedRGB = borderlineColorRGB + (1.0 - borderlineColorAlpha) * textureColor.rgb;
163 // TODO : Need to find some way without division
164 return vec4(finalMultipliedRGB / finalAlpha, finalAlpha);
166 return mix(textureColor, vec4(borderlineColorRGB, borderlineColorAlpha), borderlineOpacity);
170 #ifdef IS_REQUIRED_BLUR
171 #elif defined(IS_REQUIRED_ROUNDED_CORNER)
172 mediump float calculateCornerOpacity()
174 mediump float potential = gPotential;
176 // default opacity is 1.0
177 mediump float opacity = 1.0;
179 // calculate borderline opacity by potential
180 if(potential > gMaxOutlinePotential)
182 // potential is out of borderline range. just discard here
185 else if(potential > gMinOutlinePotential)
187 opacity = 1.0 - smoothstep(gMinOutlinePotential, gMaxOutlinePotential, potential);
193 #ifdef IS_REQUIRED_BLUR
194 mediump float calculateBlurOpacity()
196 // Don't use borderline!
197 mediump vec2 v = gDiff;
198 mediump float cy = gRadius + blurRadius;
199 mediump float cr = gRadius + blurRadius;
201 #ifdef IS_REQUIRED_ROUNDED_CORNER
202 // This routine make perfect circle. If corner radius is not exist, we don't consider prefect circle.
203 cy = min(cy, min(vRectSize.x, vRectSize.y) - gRadius);
205 v = vec2(min(v.x, v.y), max(v.x, v.y));
208 mediump float potential = 0.0;
209 mediump float alias = min(gRadius, 1.0);
210 mediump float potentialMin = cy + gRadius - blurRadius - alias;
211 mediump float potentialMax = cy + gRadius + blurRadius + alias;
213 // move center of circles for reduce defact
214 mediump float cyDiff = min(cy, 0.2 * blurRadius);
218 mediump float diffFromBaseline = cy * v.y - (cy + cr) * v.x;
220 if(diffFromBaseline > 0.0)
222 // out of calculation bound.
225 // for anti-alias when blurRaidus = 0.0
226 mediump float heuristicBaselineScale = max(1.0 , cr * (cr + cy));
227 mediump float potentialDiff = min(alias, diffFromBaseline / heuristicBaselineScale);
228 potentialMin += potentialDiff;
229 potentialMax -= potentialDiff;
233 // get some circle centered (x, x) and radius (r = cr / cy * x)
234 // s.t. point v is on that circle
235 // highest point of that circle is (x, x + r) and potential is x + r
237 // solve (v.x - x)^2 + (v.y - x)^2 = (cr / cy * x)^2
238 #ifdef IS_REQUIRED_ROUNDED_CORNER
239 // Note : lowspec HW cannot calculate here. need to reduce numeric error
240 highp float A = (cr * cr - 2.0 * cy * cy);
241 highp float B = cy * (v.x + v.y);
242 highp float V = dot(v,v);
243 highp float D = B * B + A * V;
244 potential = V * (cr + cy) / (sqrt(D) + B);
246 // We can simplify this value cause cy = 0.8 * blurRadius, cr = 1.2 * blurRadius
247 // potential = 5.0*(sqrt(4.0*(v.x+v.y)^2 + dot(v,v)) - 2.0*(v.x+v.y));
248 // = 10.0*(v.x+v.y) * (sqrt(1.0 + (length(v) / (2.0*(v.x+v.y)))^2) - 1.0);
249 // = 10.0*(v.x+v.y) * (sqrt(1.25 - x + x^2) - 1.0);
250 // ~= 10.0*(v.x+v.y) * (0.11803399 - 0.44721360x + 0.35777088x^2 - 0.14310x^3 + O(x^5)) (Taylor series)
251 // ~= -1.0557281 * (v.x + v.y) + 2.236068 * length(v) - ~~~ (here, x <= 0.5 * (1.0 - sqrt(0.5)) < 0.1464467)
252 // Note : This simplify need cause we should use it on lowspec HW.
253 mediump float x = 0.5 * (1.0 - length(v) / (v.x + v.y));
254 potential = -1.0557281 * (v.x + v.y) + 2.236068 * length(v) + 10.0 * (v.x + v.y) * (0.35777088 - 0.14310 * x) * x * x;
258 return 1.0 - smoothstep(potentialMin, potentialMax, potential);
264 lowp vec4 targetColor = vec4(mixColor, 1.0) * uColor;
266 #if defined(IS_REQUIRED_BLUR) || defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE)
267 // skip most potential calculate for performance
268 if(abs(vPosition.x) < vOptRectSize.x && abs(vPosition.y) < vOptRectSize.y)
270 OUT_COLOR = targetColor;
274 PreprocessPotential();
277 #ifdef IS_REQUIRED_BLUR
278 #elif defined(IS_REQUIRED_BORDERLINE)
279 targetColor = convertBorderlineColor(targetColor);
281 OUT_COLOR = targetColor;
283 #ifdef IS_REQUIRED_BLUR
284 mediump float opacity = calculateBlurOpacity();
285 OUT_COLOR.a *= opacity;
286 #elif defined(IS_REQUIRED_ROUNDED_CORNER)
287 mediump float opacity = calculateCornerOpacity();
288 OUT_COLOR.a *= opacity;
291 #if defined(IS_REQUIRED_BLUR) || defined(IS_REQUIRED_ROUNDED_CORNER) || defined(IS_REQUIRED_BORDERLINE)