-inline ShaderEffect CreateDistanceFieldEffect()
-{
- std::string fragmentShaderPrefix(
- "#extension GL_OES_standard_derivatives : enable\n"
- "\n"
- );
-
- std::string fragmentShader(
- "uniform mediump float uSmoothing;\n"
- "uniform mediump float uGlowBoundary;\n"
- "uniform mediump vec2 uOutlineParams;\n"
- "uniform lowp vec4 uOutlineColor;\n"
- "uniform lowp vec4 uShadowColor;\n"
- "uniform mediump vec2 uShadowOffset;\n"
- "uniform lowp vec4 uGlowColor;\n"
- "uniform lowp float uDoOutline;\n"
- "uniform lowp float uDoShadow;\n"
- "uniform lowp float uDoGlow;\n"
- "\n"
- "void main()\n"
- "{\n"
- " // sample distance field\n"
- " mediump float distance = texture2D(sTexture, vTexCoord).a;\n"
- " mediump float smoothWidth = fwidth(distance);\n"
- " mediump float alphaFactor = smoothstep(uSmoothing - smoothWidth, uSmoothing + smoothWidth, distance);\n"
- " lowp vec4 color;\n"
- " if (uDoShadow == 0.0)\n"
- " {\n"
- " mediump float alpha = uColor.a * alphaFactor;\n"
- " lowp vec4 rgb = uColor;\n"
- "\n"
- " if (uDoOutline > 0.0)\n"
- " {\n"
- " mediump float outlineWidth = uOutlineParams[1] + smoothWidth;\n"
- " mediump float outlineBlend = smoothstep(uOutlineParams[0] - outlineWidth, uOutlineParams[0] + outlineWidth, distance);\n"
- " alpha = smoothstep(uSmoothing - smoothWidth, uSmoothing + smoothWidth, distance);\n"
- " rgb = mix(uOutlineColor, uColor, outlineBlend);\n"
- " }\n"
- "\n"
- " if (uDoGlow > 0.0)\n"
- " {\n"
- " rgb = mix(uGlowColor, rgb, alphaFactor);\n"
- " alpha = smoothstep(uGlowBoundary, uSmoothing, distance);\n"
- " }\n"
- "\n"
- " // set fragment color\n"
- " color = vec4(rgb.rgb, alpha);\n"
- " }\n"
- "\n"
- " else // (uDoShadow > 0.0)\n"
- " {\n"
- " mediump float shadowDistance = texture2D(sTexture, vTexCoord - uShadowOffset).a;\n"
- " mediump float inText = alphaFactor;\n"
- " mediump float inShadow = smoothstep(uSmoothing - smoothWidth, uSmoothing + smoothWidth, shadowDistance);\n"
- "\n"
- " // inside object, outside shadow\n"
- " if (inText == 1.0)\n"
- " {\n"
- " color = uColor;\n"
- " }\n"
- " // inside object, outside shadow\n"
- " else if ((inText != 0.0) && (inShadow == 0.0))\n"
- " {\n"
- " color = uColor;\n"
- " color.a *= inText;\n"
- " }\n"
- " // outside object, completely inside shadow\n"
- " else if ((inText == 0.0) && (inShadow == 1.0))\n"
- " {\n"
- " color = uShadowColor;\n"
- " }\n"
- " // inside object, completely inside shadow\n"
- " else if ((inText != 0.0) && (inShadow == 1.0))\n"
- " {\n"
- " color = mix(uShadowColor, uColor, inText);\n"
- " color.a = uShadowColor.a;\n"
- " }\n"
- " // inside object, inside shadow's border\n"
- " else if ((inText != 0.0) && (inShadow != 0.0))\n"
- " {\n"
- " color = mix(uShadowColor, uColor, inText);\n"
- " color.a *= max(inText, inShadow);\n"
- " }\n"
- " // inside shadow's border\n"
- " else if (inShadow != 0.0)\n"
- " {\n"
- " color = uShadowColor;\n"
- " color.a *= inShadow;\n"
- " }\n"
- " // outside shadow and object\n"
- " else \n"
- " {\n"
- " color.a = 0.0;\n"
- " }\n"
- "\n"
- " }\n"
- "\n"
- " gl_FragColor = color;\n"
- "\n"
- "}\n"
- );
-
- // Create the implementation, temporarily owned on stack
- Dali::ShaderEffect shaderEffect = Dali::ShaderEffect::NewWithPrefix(
- "", "",
- fragmentShaderPrefix, fragmentShader,
- ShaderEffect::GeometryHints( ShaderEffect::HINT_BLENDING));
-
- shaderEffect.SetUniform("uSmoothing",0.5f);
- shaderEffect.SetUniform("uOutlineColor",Color::BLACK);
- shaderEffect.SetUniform("uOutlineParams",Vector2(0.51f, 0.0f));
- shaderEffect.SetUniform("uGlowBoundary",0.4f);
- shaderEffect.SetUniform("uGlowColor",Color::GREEN);
- shaderEffect.SetUniform("uShadowColor",Vector4(0.0f, 0.0f, 0.0f, 0.4f));
-
- // TODO: find a way to set the shadow offset in texel coordinates instead of UVs.
- shaderEffect.SetUniform("uShadowOffset",Vector2(0.05f, 0.05f));
-
- // Default:
- shaderEffect.SetUniform("uDoOutline",false);
- shaderEffect.SetUniform("uDoGlow",false);
- shaderEffect.SetUniform("uDoShadow",false);
-
- return shaderEffect;
-}
-