diff --git a/data/shaders/crt-lottes.frag b/data/shaders/crt-lottes.frag new file mode 100644 index 0000000..79e0a71 --- /dev/null +++ b/data/shaders/crt-lottes.frag @@ -0,0 +1,127 @@ +//uniform sampler2D source[]; +//uniform vec4 sourceSize[]; +//uniform vec4 targetSize; + +in vec2 texCoord; +out vec4 fragColor; + +uniform sampler2D tex; + +// Emulated input resolution. + vec2 res=vec2(256.0,144.0);//sourceSize[0].xy; + +// Hardness of scanline. +// -8.0 = soft +// -16.0 = medium +float hardScan=-8.0; + +// Hardness of pixels in scanline. +// -2.0 = soft +// -4.0 = hard +float hardPix=-3.0; + +// Display warp. +// 0.0 = none +// 1.0/8.0 = extreme +vec2 warp=vec2(1.0/32.0,1.0/24.0); + +// Amount of shadow mask. +float maskDark=0.5; +float maskLight=1.5; + +//------------------------------------------------------------------------ + +// sRGB to Linear. +// Assuing using sRGB typed textures this should not be needed. +float ToLinear1(float c){return(c<=0.04045)?c/12.92:pow((c+0.055)/1.055,2.4);} +vec3 ToLinear(vec3 c){return vec3(ToLinear1(c.r),ToLinear1(c.g),ToLinear1(c.b));} + +// Linear to sRGB. +// Assuing using sRGB typed textures this should not be needed. +float ToSrgb1(float c){return(c<0.0031308?c*12.92:1.055*pow(c,0.41666)-0.055);} +vec3 ToSrgb(vec3 c){return vec3(ToSrgb1(c.r),ToSrgb1(c.g),ToSrgb1(c.b));} + +// Nearest emulated sample given floating point position and texel offset. +// Also zero's off screen. +vec3 Fetch(vec2 pos,vec2 off){ + pos=(floor(pos*res+off)+vec2(0.5,0.5))/res; + return ToLinear(1.2 * texture2D(tex,pos.xy,-16.0).rgb);} //vec2??? + +// Distance in emulated pixels to nearest texel. +vec2 Dist(vec2 pos){pos=pos*res;return -((pos-floor(pos))-vec2(0.5));} + +// 1D Gaussian. +float Gaus(float pos,float scale){return exp2(scale*pos*pos);} + +// 3-tap Gaussian filter along horz line. +vec3 Horz3(vec2 pos,float off){ + vec3 b=Fetch(pos,vec2(-1.0,off)); + vec3 c=Fetch(pos,vec2( 0.0,off)); + vec3 d=Fetch(pos,vec2( 1.0,off)); + float dst=Dist(pos).x; + // Convert distance to weight. + float scale=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. +vec3 Horz5(vec2 pos,float off){ + vec3 a=Fetch(pos,vec2(-2.0,off)); + vec3 b=Fetch(pos,vec2(-1.0,off)); + vec3 c=Fetch(pos,vec2( 0.0,off)); + vec3 d=Fetch(pos,vec2( 1.0,off)); + vec3 e=Fetch(pos,vec2( 2.0,off)); + float dst=Dist(pos).x; + // Convert distance to weight. + float scale=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);} + +// Return scanline weight. +float Scan(vec2 pos,float off){ + float dst=Dist(pos).y; + return Gaus(dst+off,hardScan);} + +// Allow nearest three lines to effect pixel. +vec3 Tri(vec2 pos){ + vec3 a=Horz3(pos,-1.0); + vec3 b=Horz5(pos, 0.0); + vec3 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;} + +// Distortion of scanlines, and end of screen alpha. +vec2 Warp(vec2 pos){ + pos=pos*2.0-1.0; + pos*=vec2(1.0+(pos.y*pos.y)*warp.x,1.0+(pos.x*pos.x)*warp.y); + return pos*0.5+0.5;} + +// Shadow mask. +vec3 Mask(vec2 pos){ + pos.x+=pos.y*3.0; + vec3 mask=vec3(maskDark,maskDark,maskDark); + pos.x=fract(pos.x/6.0); + if(pos.x<0.333)mask.r=maskLight; + else if(pos.x<0.666)mask.g=maskLight; + else mask.b=maskLight; + return mask;} + +void main() { + vec2 pos = gl_FragCoord.xy/vec2(256.0*4.0,144.0*4.0);//targetSize.xy; + hardScan=-12.0; +// maskDark=maskLight; + pos=Warp(gl_FragCoord.xy/vec2(256.0*4.0,144.0*4.0)); + fragColor.rgb=Tri(pos)*Mask(gl_FragCoord.xy); + fragColor.a=1.0; + fragColor = vec4(ToSrgb(fragColor.rgb), fragColor.a); +} diff --git a/src/system.c b/src/system.c index a6a67b9..42cac15 100644 --- a/src/system.c +++ b/src/system.c @@ -1129,10 +1129,10 @@ static s32 start(s32 argc, char **argv, const char* folder) GPU_Target* screen = GPU_Init(Width, Height, GPU_INIT_DISABLE_VSYNC); GPU_Image* texture = GPU_CreateImage(TIC80_FULLWIDTH, TIC80_FULLHEIGHT, GPU_FORMAT_BGRA); - // GPU_SetImageFilter(texture, GPU_FILTER_NEAREST); + GPU_SetImageFilter(texture, GPU_FILTER_NEAREST); u32 crt_shader = 0; - load_shader_program(&crt_shader, "data/shaders/common.vert", "data/shaders/crt-geom.frag"); + load_shader_program(&crt_shader, "data/shaders/common.vert", "data/shaders/crt-lottes.frag"); { u64 nextTick = SDL_GetPerformanceCounter(); const u64 Delta = SDL_GetPerformanceFrequency() / TIC_FRAMERATE;