58 lines
2.1 KiB
HLSL
58 lines
2.1 KiB
HLSL
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// A minimal pixel shader that shows some raster bars
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// The terminal graphics as a texture
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Texture2D shaderTexture;
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SamplerState samplerState;
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// Terminal settings such as the resolution of the texture
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cbuffer PixelShaderSettings {
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// Time since pixel shader was enabled
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float Time;
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// UI Scale
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float Scale;
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// Resolution of the shaderTexture
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float2 Resolution;
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// Background color as rgba
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float4 Background;
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};
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// A pixel shader is a program that given a texture coordinate (tex) produces a color
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// Just ignore the pos parameter
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float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
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{
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// Read the color value at the current texture coordinate (tex)
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// float4 is tuple of 4 floats, rgba
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float4 color = shaderTexture.Sample(samplerState, tex);
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// Read the color value at some offset, will be used as shadow
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float4 ocolor = shaderTexture.Sample(samplerState, tex+2.0*Scale*float2(-1.0, -1.0)/Resolution.y);
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// Thickness of raster
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const float thickness = 0.1;
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float ny = floor(tex.y/thickness);
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float my = tex.y%thickness;
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const float pi = 3.141592654;
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// ny is used to compute the rasterbar base color
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float cola = ny*2.0*pi;
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float3 col = 0.75+0.25*float3(sin(cola*0.111), sin(cola*0.222), sin(cola*0.333));
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// my is used to compute the rasterbar brightness
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// smoothstep is a great little function: https://en.wikipedia.org/wiki/Smoothstep
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float brightness = 1.0-smoothstep(0.0, thickness*0.5, abs(my - 0.5*thickness));
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float3 rasterColor = col*brightness;
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// lerp(x, y, a) is another very useful function: https://en.wikipedia.org/wiki/Linear_interpolation
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float3 final = rasterColor;
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// Create the drop shadow of the terminal graphics
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// .w is the alpha channel, 0 is fully transparent and 1 is fully opaque
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final = lerp(final, float(0.0), ocolor.w);
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// Draw the terminal graphics
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final = lerp(final, color.xyz, color.w);
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// Return the final color, set alpha to 1 (ie opaque)
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return float4(final, 1.0);
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}
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