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