Merge "Remove return; statement at fragment shader" into devel/master

[platform/core/uifw/dali-toolkit.git] / dali-toolkit / internal / graphics / shaders / image-visual-shader.frag

diff --git a/dali-toolkit/internal/graphics/shaders/image-visual-shader.frag b/dali-toolkit/internal/graphics/shaders/image-visual-shader.frag
index 676c02b..703c649 100644 (file)
--- a/dali-toolkit/internal/graphics/shaders/image-visual-shader.frag
+++ b/dali-toolkit/internal/graphics/shaders/image-visual-shader.frag
@@ -143,33 +143,53 @@ lowp vec4 convertBorderlineColor(lowp vec4 textureColor)
   {
     // potential is inside borderline range.
     borderlineOpacity = smoothstep(gMinInlinePotential, gMaxInlinePotential, potential);
+
+    // Muliply borderlineWidth to resolve very thin borderline
+    borderlineOpacity *= min(1.0, borderlineWidth);
   }
 
-  lowp vec3  BorderlineColorRGB   = borderlineColor.rgb * uActorColor.rgb;
-  lowp float BorderlineColorAlpha = borderlineColor.a * uActorColor.a;
-  BorderlineColorRGB *= mix(1.0, BorderlineColorAlpha, preMultipliedAlpha);
+  lowp vec3  borderlineColorRGB   = borderlineColor.rgb * uActorColor.rgb;
+  lowp float borderlineColorAlpha = borderlineColor.a * uActorColor.a;
+  borderlineColorRGB *= mix(1.0, borderlineColorAlpha, preMultipliedAlpha);
 
-  //calculate inside of borderline when outilneColor.a < 1.0
-  if(borderlineColor.a < 1.0)
+  // 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;
     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(BorderlineColorRGB, 0.0);
+      // potential is out of texture range.
+      textureColor = vec4(0.0);
     }
-    else if(potential > MinTexturelinePotential)
+    else
     {
-      // potential is in texture range
-      textureColor = mix(textureColor, vec4(BorderlineColorRGB, 0.0), smoothstep(MinTexturelinePotential, MaxTexturelinePotential, potential));
+      // potential is in texture range.
+      lowp float textureAlphaScale = mix(1.0, 0.0, smoothstep(MinTexturelinePotential, MaxTexturelinePotential, potential));
+      textureColor.a *= textureAlphaScale;
+      textureColor.rgb *= mix(textureColor.a, textureAlphaScale, preMultipliedAlpha);
     }
-    // TODO : need to fix here when uColor.a = 0.0 and uActorColor.a != 0
-    borderlineOpacity *= borderlineColor.a;
-    return mix(textureColor, vec4(BorderlineColorRGB, 1.0), borderlineOpacity);
+
+    borderlineColorAlpha *= borderlineOpacity;
+    borderlineColorRGB *= mix(borderlineColorAlpha, borderlineOpacity, preMultipliedAlpha);
+    // 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 * mix(1.0 / finalAlpha, 1.0, preMultipliedAlpha), finalAlpha);
   }
-  return mix(textureColor, vec4(BorderlineColorRGB, BorderlineColorAlpha), borderlineOpacity);
+  return mix(textureColor, vec4(borderlineColorRGB, borderlineColorAlpha), borderlineOpacity);
 }
 #endif
 
@@ -213,19 +233,24 @@ void main()
   if(abs(vPosition.x) < vOptRectSize.x && abs(vPosition.y) < vOptRectSize.y)
   {
     OUT_COLOR = textureColor;
-    return;
   }
-  PreprocessPotential();
+  else
+  {
+    PreprocessPotential();
 #endif
 
 #if IS_REQUIRED_BORDERLINE
-  textureColor = convertBorderlineColor(textureColor);
+    textureColor = convertBorderlineColor(textureColor);
 #endif
-  OUT_COLOR = textureColor;
+    OUT_COLOR = textureColor;
 
 #if IS_REQUIRED_ROUNDED_CORNER
-  mediump float opacity = calculateCornerOpacity();
-  OUT_COLOR.a *= opacity;
-  OUT_COLOR.rgb *= mix(1.0, opacity, preMultipliedAlpha);
+    mediump float opacity = calculateCornerOpacity();
+    OUT_COLOR.a *= opacity;
+    OUT_COLOR.rgb *= mix(1.0, opacity, preMultipliedAlpha);
+#endif
+
+#if IS_REQUIRED_ROUNDED_CORNER || IS_REQUIRED_BORDERLINE
+  }
 #endif
 }