From 69efa0f46fc2d1d7cbcec729f5143c2c1bbfd056 Mon Sep 17 00:00:00 2001 From: Connor McLaughlin Date: Thu, 13 Oct 2022 17:42:31 +1000 Subject: [PATCH] Shaders: Add crt-lottes.glsl --- data/resources/shaders/crt-lottes.glsl | 405 +++++++++++++++++++++++++ 1 file changed, 405 insertions(+) create mode 100644 data/resources/shaders/crt-lottes.glsl diff --git a/data/resources/shaders/crt-lottes.glsl b/data/resources/shaders/crt-lottes.glsl new file mode 100644 index 000000000..99ae05be2 --- /dev/null +++ b/data/resources/shaders/crt-lottes.glsl @@ -0,0 +1,405 @@ +// PUBLIC DOMAIN CRT STYLED SCAN-LINE SHADER +// +// by Timothy Lottes +// +// This is more along the style of a really good CGA arcade monitor. +// With RGB inputs instead of NTSC. +// The shadow mask example has the mask rotated 90 degrees for less chromatic aberration. +// +// Left it unoptimized to show the theory behind the algorithm. +// +// It is an example what I personally would want as a display option for pixel art games. +// Please take and use, change, or whatever. + +/* +[configuration] + +[OptionRangeFloat] +GUIName = Scanline Weight +OptionName = hardScan +MinValue = -20.0 +MaxValue = 0.0 +StepAmount = 1.0 +DefaultValue = -8.0 + +[OptionRangeFloat] +GUIName = Scanline Scale +OptionName = hardPix +MinValue = -20.0 +MaxValue = 0.0 +StepAmount = 1.0 +DefaultValue = -3.0 + +[OptionRangeFloat] +GUIName = Screen Warp X +OptionName = warpX +MinValue = 0.0 +MaxValue = 0.125 +StepAmount = 0.01 +DefaultValue = 0.031 + +[OptionRangeFloat] +GUIName = Screen Warp Y +OptionName = warpY +MinValue = 0.0 +MaxValue = 0.125 +StepAmount = 0.01 +DefaultValue = 0.041 + +[OptionRangeFloat] +GUIName = Mask Dark +OptionName = maskDark +MinValue = 0.0 +MaxValue = 2.0 +StepAmount = 0.1 +DefaultValue = 0.5 + +[OptionRangeFloat] +GUIName = Mask Light +OptionName = maskLight +MinValue = 0.0 +MaxValue = 2.0 +StepAmount = 0.1 +DefaultValue = 1.5 + +[OptionRangeInteger] +GUIName = Shadow Mask Type +OptionName = shadowMask +MinValue = 0 +MaxValue = 4 +StepAmount = 1 +DefaultValue = 3 + +[OptionRangeFloat] +GUIName = Brightess Boost +OptionName = brightBoost +MinValue = 0.0 +MaxValue = 2.0 +StepAmount = 0.05 +DefaultValue = 1.0 + +[OptionRangeFloat] +GUIName = Bloom Soft X +OptionName = hardBloomPix +MinValue = -2.0 +MaxValue = -0.5 +StepAmount = 0.1 +DefaultValue = -1.5 + +[OptionRangeFloat] +GUIName = Bloom Soft Y +OptionName = hardBloomScan +MinValue = -4.0 +MaxValue = -1.0 +StepAmount = 0.1 +DefaultValue = -2.0 + +[OptionRangeFloat] +GUIName = Bloom Amount +OptionName = bloomAmount +MinValue = 0.0 +MaxValue = 1.0 +StepAmount = 0.05 +DefaultValue = 0.15 + +[OptionRangeFloat] +GUIName = Filter Kernel Shape +OptionName = shape +MinValue = 0.0 +MaxValue = 10.0 +StepAmount = 0.05 +DefaultValue = 2.0 + +[OptionBool] +GUIName = Scale in Linear Gamma +OptionName = scaleInLinearGamma +DefaultValue = true + +[/configuration] +*/ + +//Uncomment to reduce instructions with simpler linearization +//(fixes HD3000 Sandy Bridge IGP) +//#define SIMPLE_LINEAR_GAMMA +#define DO_BLOOM + +// ------------- // + +// sRGB to Linear. +// Assuming using sRGB typed textures this should not be needed. +#ifdef SIMPLE_LINEAR_GAMMA +float ToLinear1(float c) +{ + return c; +} +float3 ToLinear(float3 c) +{ + return c; +} +float3 ToSrgb(float3 c) +{ + return pow(c, float3(1.0 / 2.2)); +} +#else +float ToLinear1(float c) +{ + if (!OptionEnabled(scaleInLinearGamma)) + return c; + + return(c<=0.04045) ? c/12.92 : pow((c + 0.055)/1.055, 2.4); +} + +float3 ToLinear(float3 c) +{ + if (!OptionEnabled(scaleInLinearGamma)) + return c; + + return float3(ToLinear1(c.r), ToLinear1(c.g), ToLinear1(c.b)); +} + +// Linear to sRGB. +// Assuming using sRGB typed textures this should not be needed. +float ToSrgb1(float c) +{ + if (!OptionEnabled(scaleInLinearGamma)) + return c; + + return(c<0.0031308 ? c*12.92 : 1.055*pow(c, 0.41666) - 0.055); +} + +float3 ToSrgb(float3 c) +{ + if (!OptionEnabled(scaleInLinearGamma)) + return c; + + return float3(ToSrgb1(c.r), ToSrgb1(c.g), ToSrgb1(c.b)); +} +#endif + +// Nearest emulated sample given floating point position and texel offset. +// Also zero's off screen. +float3 Fetch(float2 pos,float2 off){ + pos=(floor(pos*GetResolution()+off)+float2(0.5,0.5))*GetInvResolution(); +#ifdef SIMPLE_LINEAR_GAMMA + return ToLinear(GetOption(brightBoost) * pow(SampleLocation(pos.xy).rgb, float3(2.2))); +#else + return ToLinear(GetOption(brightBoost) * SampleLocation(pos.xy).rgb); +#endif +} + +// Distance in emulated pixels to nearest texel. +float2 Dist(float2 pos) +{ + pos = pos*GetOriginalSize().xy; + + return -((pos - floor(pos)) - float2(0.5, 0.5)); +} + +// 1D Gaussian. +float Gaus(float pos, float scale) +{ + return exp2(scale*pow(abs(pos), GetOption(shape))); +} + +// 3-tap Gaussian filter along horz line. +float3 Horz3(float2 pos, float off) +{ + float3 b = Fetch(pos, float2(-1.0, off)); + float3 c = Fetch(pos, float2( 0.0, off)); + float3 d = Fetch(pos, float2( 1.0, off)); + float dst = Dist(pos).x; + + // Convert distance to weight. + float scale = GetOption(hardPix); + float wb = Gaus(dst-1.0,scale); + float wc = Gaus(dst+0.0,scale); + float wd = Gaus(dst+1.0,scale); + + // Return filtered sample. + return (b*wb+c*wc+d*wd)/(wb+wc+wd); +} + +// 5-tap Gaussian filter along horz line. +float3 Horz5(float2 pos,float off){ + float3 a = Fetch(pos,float2(-2.0, off)); + float3 b = Fetch(pos,float2(-1.0, off)); + float3 c = Fetch(pos,float2( 0.0, off)); + float3 d = Fetch(pos,float2( 1.0, off)); + float3 e = Fetch(pos,float2( 2.0, off)); + + float dst = Dist(pos).x; + // Convert distance to weight. + float scale = GetOption(hardPix); + float wa = Gaus(dst - 2.0, scale); + float wb = Gaus(dst - 1.0, scale); + float wc = Gaus(dst + 0.0, scale); + float wd = Gaus(dst + 1.0, scale); + float we = Gaus(dst + 2.0, scale); + + // Return filtered sample. + return (a*wa+b*wb+c*wc+d*wd+e*we)/(wa+wb+wc+wd+we); +} + +// 7-tap Gaussian filter along horz line. +float3 Horz7(float2 pos,float off) +{ + float3 a = Fetch(pos, float2(-3.0, off)); + float3 b = Fetch(pos, float2(-2.0, off)); + float3 c = Fetch(pos, float2(-1.0, off)); + float3 d = Fetch(pos, float2( 0.0, off)); + float3 e = Fetch(pos, float2( 1.0, off)); + float3 f = Fetch(pos, float2( 2.0, off)); + float3 g = Fetch(pos, float2( 3.0, off)); + + float dst = Dist(pos).x; + // Convert distance to weight. + float scale = GetOption(hardBloomPix); + float wa = Gaus(dst - 3.0, scale); + float wb = Gaus(dst - 2.0, scale); + float wc = Gaus(dst - 1.0, scale); + float wd = Gaus(dst + 0.0, scale); + float we = Gaus(dst + 1.0, scale); + float wf = Gaus(dst + 2.0, scale); + float wg = Gaus(dst + 3.0, scale); + + // Return filtered sample. + return (a*wa+b*wb+c*wc+d*wd+e*we+f*wf+g*wg)/(wa+wb+wc+wd+we+wf+wg); +} + +// Return scanline weight. +float Scan(float2 pos, float off) +{ + float dst = Dist(pos).y; + + return Gaus(dst + off, GetOption(hardScan)); +} + +// Return scanline weight for bloom. +float BloomScan(float2 pos, float off) +{ + float dst = Dist(pos).y; + + return Gaus(dst + off, GetOption(hardBloomScan)); +} + +// Allow nearest three lines to effect pixel. +float3 Tri(float2 pos) +{ + float3 a = Horz3(pos,-1.0); + float3 b = Horz5(pos, 0.0); + float3 c = Horz3(pos, 1.0); + + float wa = Scan(pos,-1.0); + float wb = Scan(pos, 0.0); + float wc = Scan(pos, 1.0); + + return a*wa + b*wb + c*wc; +} + +// Small bloom. +float3 Bloom(float2 pos) +{ + float3 a = Horz5(pos,-2.0); + float3 b = Horz7(pos,-1.0); + float3 c = Horz7(pos, 0.0); + float3 d = Horz7(pos, 1.0); + float3 e = Horz5(pos, 2.0); + + float wa = BloomScan(pos,-2.0); + float wb = BloomScan(pos,-1.0); + float wc = BloomScan(pos, 0.0); + float wd = BloomScan(pos, 1.0); + float we = BloomScan(pos, 2.0); + + return a*wa+b*wb+c*wc+d*wd+e*we; +} + +// Distortion of scanlines, and end of screen alpha. +float2 Warp(float2 pos) +{ + pos = pos*2.0-1.0; + pos *= float2(1.0 + (pos.y*pos.y)*GetOption(warpX), 1.0 + (pos.x*pos.x)*GetOption(warpY)); + + return pos*0.5 + 0.5; +} + +// Shadow mask. +float3 Mask(float2 pos) +{ + float3 mask = float3(GetOption(maskDark), GetOption(maskDark), GetOption(maskDark)); + + // Very compressed TV style shadow mask. + if (GetOption(shadowMask) == 1) + { + float line_ = GetOption(maskLight); + float odd = 0.0; + + if (fract(pos.x*0.166666666) < 0.5) odd = 1.0; + if (fract((pos.y + odd) * 0.5) < 0.5) line_ = GetOption(maskDark); + + pos.x = fract(pos.x*0.333333333); + + if (pos.x < 0.333) mask.r = GetOption(maskLight); + else if (pos.x < 0.666) mask.g = GetOption(maskLight); + else mask.b = GetOption(maskLight); + mask*=line_; + } + + // Aperture-grille. + else if (GetOption(shadowMask) == 2) + { + pos.x = fract(pos.x*0.333333333); + + if (pos.x < 0.333) mask.r = GetOption(maskLight); + else if (pos.x < 0.666) mask.g = GetOption(maskLight); + else mask.b = GetOption(maskLight); + } + + // Stretched VGA style shadow mask (same as prior shaders). + else if (GetOption(shadowMask) == 3) + { + pos.x += pos.y*3.0; + pos.x = fract(pos.x*0.166666666); + + if (pos.x < 0.333) mask.r = GetOption(maskLight); + else if (pos.x < 0.666) mask.g = GetOption(maskLight); + else mask.b = GetOption(maskLight); + } + + // VGA style shadow mask. + else if (GetOption(shadowMask) == 4) + { + pos.xy = floor(pos.xy*float2(1.0, 0.5)); + pos.x += pos.y*3.0; + pos.x = fract(pos.x*0.166666666); + + if (pos.x < 0.333) mask.r = GetOption(maskLight); + else if (pos.x < 0.666) mask.g = GetOption(maskLight); + else mask.b = GetOption(maskLight); + } + + return mask; +} + +void main() +{ + float2 pos = Warp(GetCoordinates()); + float3 outColor = Tri(pos); + +#ifdef DO_BLOOM + //Add Bloom + outColor.rgb += Bloom(pos)*GetOption(bloomAmount); +#endif + + if (GetOption(shadowMask) > 0.0) + outColor.rgb *= Mask(gl_FragCoord.xy * 1.000001); + +#ifdef GL_ES /* TODO/FIXME - hacky clamp fix */ + float2 bordertest = (pos); + if ( bordertest.x > 0.0001 && bordertest.x < 0.9999 && bordertest.y > 0.0001 && bordertest.y < 0.9999) + outColor.rgb = outColor.rgb; + else + outColor.rgb = float3(0.0); +#endif + SetOutput(float4(ToSrgb(outColor.rgb), 1.0)); +}