IceEffect.ux

<DockPanel ux:Class="IceEffect">
	<Button Dock="Bottom" Text="Reset">
		<Clicked>
			<ClearRetainBuffer Target="HeatBuffer" />
		</Clicked>
	</Button>

	<ShaderControl BoxSizing="FillAspect" Aspect="1" HitTestMode="LocalBoundsAndChildren">
		<RetainBuffer ux:Name="HeatBuffer" Width="64" Height="64" ClearColor="0, 0, 0, 0" />
		<TempBuffer ux:Name="WorkBuffer" Width="64" Height="64" />

		<Pass Target="WorkBuffer">
			<BufferUniform Buffer="HeatBuffer" UniformName="HeatTex" />

			<Code ux:Binding="VertexCode">
				attribute vec2 VertexPosition;

				varying vec2 TexCoords;

				void main()
				{
					TexCoords = VertexPosition;
					gl_Position = vec4(VertexPosition * 2.0 - 1.0, 0, 1);
				}
			</Code>
			<Code ux:Binding="FragmentCode">
				uniform sampler2D HeatTex;

				varying vec2 TexCoords;

				void main()
				{
					gl_FragColor = texture2D(HeatTex, TexCoords);
				}
			</Code>
		</Pass>

		<Pass Target="HeatBuffer">
			<BufferUniform Buffer="WorkBuffer" UniformName="HeatTex" />

			<PointerXUniform UniformName="PointerX" />
			<PointerYUniform UniformName="PointerY" />
			<PointerDownUniform UniformName="PointerDown" />

			<Code ux:Binding="VertexCode">
				attribute vec2 VertexPosition;

				varying vec2 TexCoords;

				void main()
				{
					TexCoords = VertexPosition;
					gl_Position = vec4(VertexPosition * 2.0 - 1.0, 0, 1);
				}
			</Code>
			<Code ux:Binding="FragmentCode">
				uniform sampler2D HeatTex;

				varying vec2 TexCoords;

				uniform float PointerX;
				uniform float PointerY;
				uniform float PointerDown;

				void main()
				{
					const float texelSize = 1.0 / 64.0;

					float heat = texture2D(HeatTex, TexCoords).x;

					// Affect heat with neighboring heats
					heat =
						(heat +
						texture2D(HeatTex, TexCoords - vec2(texelSize, 0.0)).x +
						texture2D(HeatTex, TexCoords + vec2(texelSize, 0.0)).x +
						texture2D(HeatTex, TexCoords + vec2(0.0, texelSize)).x +
						texture2D(HeatTex, TexCoords - vec2(0.0, texelSize)).x) / 5.0;

					// Affect heat with pointer
					heat += max((1.0 - distance(TexCoords, vec2(PointerX, PointerY)) * 10.0), 0.0) * 0.5 * PointerDown;

					// Dampen heat
					heat -= 0.002;

					gl_FragColor = vec4(heat, 0, 0, 0);
				}
			</Code>
		</Pass>

		<Pass>
			<LocalToClipMatrixUniform UniformName="LocalToClipMatrix" />
			<SizeUniform UniformName="Size" />

			<BufferUniform Buffer="HeatBuffer" UniformName="HeatTex" />
			<ImageUniform File="Assets/icecracks.png" UniformName="CracksTex" />
			<ImageUniform File="Assets/icecolor.png" UniformName="ColorTex" />
			<ImageUniform Url="http://www.babylonpuzzles.com/6866-thickbox_default/500-pcs---curious-kitten---square-by-ravensburger.jpg" UniformName="PictureTex" />

			<Code ux:Binding="VertexCode">
				uniform mat4 LocalToClipMatrix;
				uniform vec2 Size;

				attribute vec2 VertexPosition;

				varying vec2 TexCoords;

				void main()
				{
					TexCoords = VertexPosition;
					gl_Position = LocalToClipMatrix * vec4(VertexPosition * Size, 0, 1);
				}
			</Code>
			<Code ux:Binding="FragmentCode">
				uniform sampler2D HeatTex;
				uniform sampler2D CracksTex;
				uniform sampler2D ColorTex;
				uniform sampler2D PictureTex;

				varying vec2 TexCoords;

				void main()
				{
					float inputHeat = texture2D(HeatTex, TexCoords).x;
					float heat = mix(inputHeat, clamp(inputHeat * 5.0, 0.0, 1.0), texture2D(CracksTex, TexCoords).x);

					float white = pow(1.0 - clamp(abs(heat - 0.2) / 0.2, 0.0, 1.0), 1.6) * 0.8;

					vec3 pictureColor = texture2D(PictureTex, TexCoords).xyz;

					vec3 iceColor = mix(pictureColor, texture2D(ColorTex, TexCoords).xyz, 0.8);

					gl_FragColor = vec4(mix(iceColor, pictureColor, heat) + white, 1);
				}
			</Code>
		</Pass>
	</ShaderControl>
</DockPanel>