#version 450 /* CRT-interlaced-halation shader - pass2 Like the CRT-interlaced shader, but adds a subtle glow around bright areas of the screen. Copyright (C) 2010-2012 cgwg, Themaister and DOLLS This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. (cgwg gave their consent to have the original version of this shader distributed under the GPL in this message: http://board.byuu.org/viewtopic.php?p=26075#p26075 "Feel free to distribute my shaders under the GPL. After all, the barrel distortion code was taken from the Curvature shader, which is under the GPL." ) */ layout(push_constant) uniform Push { vec4 SourceSize; vec4 crt_interlaced_halation_refpassSize; vec4 OutputSize; uint FrameCount; } params; layout(std140, set = 0, binding = 0) uniform UBO { mat4 MVP; } global; // Comment the next line to disable interpolation in linear gamma (and // gain speed). #define LINEAR_PROCESSING // Enable screen curvature. #define CURVATURE // Enable 3x oversampling of the beam profile //#define OVERSAMPLE // Use the older, purely gaussian beam profile #define USEGAUSSIAN // Use interlacing detection; may interfere with other shaders if combined #define INTERLACED // Enable Dot-mask emulation: // Output pixels are alternately tinted green and magenta. //#define DOTMASK //Enable if using several shaders. //Disabling it reduces moire for single pass. #define MULTIPASS // Macros. #define FIX(c) max(abs(c), 1e-5); #define PI 3.141592653589 #ifdef LINEAR_PROCESSING # define TEX2D(c) pow(texture(crt_interlaced_halation_refpass, (c)), vec4(CRTgamma)) #else # define TEX2D(c) texture(crt_interlaced_halation_refpass, (c)) #endif // START of parameters // gamma of simulated CRT float CRTgamma = 2.4; // gamma of display monitor (typically 2.2 is correct) float monitorgamma = 2.2; // overscan (e.g. 1.02 for 2% overscan) vec2 overscan = vec2(1.0,1.0); // aspect ratio vec2 aspect = vec2(1.0, 0.75); // lengths are measured in units of (approximately) the width // of the monitor simulated distance from viewer to monitor float d = 2.0; // radius of curvature float R = 2.0; // tilt angle in radians // (behavior might be a bit wrong if both components are // nonzero) const vec2 angle = vec2(0.0,0.0); // size of curved corners float cornersize = 0.01; // border smoothness parameter // decrease if borders are too aliased float cornersmooth = 800.0; // END of parameters float intersect(vec2 xy, vec2 sinangle, vec2 cosangle) { float A = dot(xy,xy)+d*d; float B = 2.0*(R*(dot(xy,sinangle)-d*cosangle.x*cosangle.y)-d*d); float C = d*d + 2.0*R*d*cosangle.x*cosangle.y; return (-B-sqrt(B*B-4.0*A*C))/(2.0*A); } vec2 bkwtrans(vec2 xy, vec2 sinangle, vec2 cosangle) { float c = intersect(xy, sinangle, cosangle); vec2 point = vec2(c)*xy; point -= vec2(-R)*sinangle; point /= vec2(R); vec2 tang = sinangle/cosangle; vec2 poc = point/cosangle; float A = dot(tang,tang)+1.0; float B = -2.0*dot(poc,tang); float C = dot(poc,poc)-1.0; float a = (-B+sqrt(B*B-4.0*A*C))/(2.0*A); vec2 uv = (point-a*sinangle)/cosangle; float r = FIX(R*acos(a)); return uv*r/sin(r/R); } vec2 fwtrans(vec2 uv, vec2 sinangle, vec2 cosangle) { float r = FIX(sqrt(dot(uv,uv))); uv *= sin(r/R)/r; float x = 1.0-cos(r/R); float D = d/R + x*cosangle.x*cosangle.y+dot(uv,sinangle); return d*(uv*cosangle-x*sinangle)/D; } vec3 maxscale(vec2 sinangle, vec2 cosangle) { vec2 c = bkwtrans(-R * sinangle / (1.0 + R/d*cosangle.x*cosangle.y), sinangle, cosangle); vec2 a = vec2(0.5,0.5)*aspect; vec2 lo = vec2(fwtrans(vec2(-a.x,c.y), sinangle, cosangle).x, fwtrans(vec2(c.x,-a.y), sinangle, cosangle).y)/aspect; vec2 hi = vec2(fwtrans(vec2(+a.x,c.y), sinangle, cosangle).x, fwtrans(vec2(c.x,+a.y), sinangle, cosangle).y)/aspect; return vec3((hi+lo)*aspect*0.5,max(hi.x-lo.x,hi.y-lo.y)); } // Calculate the influence of a scanline on the current pixel. // // 'distance' is the distance in texture coordinates from the current // pixel to the scanline in question. // 'color' is the colour of the scanline at the horizontal location of // the current pixel. vec4 scanlineWeights(float distance, vec4 color) { // "wid" controls the width of the scanline beam, for each RGB // channel The "weights" lines basically specify the formula // that gives you the profile of the beam, i.e. the intensity as // a function of distance from the vertical center of the // scanline. In this case, it is gaussian if width=2, and // becomes nongaussian for larger widths. Ideally this should // be normalized so that the integral across the beam is // independent of its width. That is, for a narrower beam // "weights" should have a higher peak at the center of the // scanline than for a wider beam. #ifdef USEGAUSSIAN vec4 wid = 0.3 + 0.1 * pow(color, vec4(3.0)); vec4 weights = vec4(distance / wid); return 0.4 * exp(-weights * weights) / wid; #else vec4 wid = 2.0 + 2.0 * pow(color, vec4(4.0)); vec4 weights = vec4(distance / 0.3); return 1.4 * exp(-pow(weights * rsqrt(0.5 * wid), wid)) / (0.6 + 0.2 * wid); #endif } #pragma stage vertex layout(location = 0) in vec4 Position; layout(location = 1) in vec2 TexCoord; layout(location = 0) out vec2 vTexCoord; layout(location = 1) out vec2 one; layout(location = 2) out float mod_factor; layout(location = 3) out vec2 ilfac; layout(location = 4) out vec3 stretch; layout(location = 5) out vec2 sinangle; layout(location = 6) out vec2 cosangle; void main() { gl_Position = global.MVP * Position; vTexCoord = TexCoord; // Precalculate a bunch of useful values we'll need in the fragment // shader. sinangle = sin(angle); cosangle = cos(angle); stretch = maxscale(sinangle, cosangle); #ifdef INTERLACED ilfac = vec2(1.0,clamp(floor(params.SourceSize.y/200.0),1.0,2.0)); #else ilfac = vec2(1.0,clamp(floor(params.SourceSize.y/1000.0),1.0,2.0)); #endif // The size of one texel, in texture-coordinates. one = ilfac / params.crt_interlaced_halation_refpassSize.xy; // Resulting X pixel-coordinate of the pixel we're drawing. mod_factor = vTexCoord.x * params.crt_interlaced_halation_refpassSize.x * params.OutputSize.x / params.crt_interlaced_halation_refpassSize.x; } #pragma stage fragment layout(location = 0) in vec2 vTexCoord; layout(location = 1) in vec2 one; layout(location = 2) in float mod_factor; layout(location = 3) in vec2 ilfac; layout(location = 4) in vec3 stretch; layout(location = 5) in vec2 sinangle; layout(location = 6) in vec2 cosangle; layout(location = 0) out vec4 FragColor; layout(set = 0, binding = 2) uniform sampler2D Source; layout(set = 0, binding = 3) uniform sampler2D crt_interlaced_halation_refpass; #define mul(a, b) (b * a) void main() { // Here's a helpful diagram to keep in mind while trying to // understand the code: // // | | | | | // ------------------------------- // | | | | | // | 01 | 11 | 21 | 31 | <-- current scanline // | | @ | | | // ------------------------------- // | | | | | // | 02 | 12 | 22 | 32 | <-- next scanline // | | | | | // ------------------------------- // | | | | | // // Each character-cell represents a pixel on the output // surface, "@" represents the current pixel (always somewhere // in the bottom half of the current scan-line, or the top-half // of the next scanline). The grid of lines represents the // edges of the texels of the underlying texture. // Texture coordinates of the texel containing the active pixel. #ifdef CURVATURE vec2 cd = vTexCoord; //cd *= ORIG.texture_size / ORIG.video_size; cd = (cd-vec2(0.5))*aspect*stretch.z+stretch.xy; vec2 xy = (bkwtrans(cd, sinangle, cosangle)/overscan/aspect+vec2(0.5));// * ORIG.video_size / ORIG.texture_size; #else vec2 xy = vTexCoord; #endif vec2 cd2 = xy; //cd2 *= ORIG.texture_size / ORIG.video_size; cd2 = (cd2 - vec2(0.5)) * overscan + vec2(0.5); cd2 = min(cd2, vec2(1.0)-cd2) * aspect; vec2 cdist = vec2(cornersize); cd2 = (cdist - min(cd2,cdist)); float dist = sqrt(dot(cd2,cd2)); float cval = clamp((cdist.x-dist)*cornersmooth,0.0, 1.0); vec2 xy2 = ((xy-vec2(0.5))*vec2(1.0,1.0)+vec2(0.5));//*IN.video_size/IN.texture_size; // Of all the pixels that are mapped onto the texel we are // currently rendering, which pixel are we currently rendering? vec2 ilfloat = vec2(0.0,ilfac.y > 1.5 ? mod(vec2(params.FrameCount,params.FrameCount).x,2.0) : 0.0); vec2 ratio_scale = (xy * params.SourceSize.xy - vec2(0.5) + ilfloat)/ilfac; #ifdef OVERSAMPLE //float filter = fwidth(ratio_scale.y); float os_filter = params.SourceSize.y / params.OutputSize.y; #endif vec2 uv_ratio = fract(ratio_scale); // Snap to the center of the underlying texel. xy = (floor(ratio_scale)*ilfac + vec2(0.5) - ilfloat) / params.SourceSize.xy; // Calculate Lanczos scaling coefficients describing the effect // of various neighbour texels in a scanline on the current // pixel. vec4 coeffs = PI * vec4(1.0 + uv_ratio.x, uv_ratio.x, 1.0 - uv_ratio.x, 2.0 - uv_ratio.x); // Prevent division by zero. coeffs = FIX(coeffs); // Lanczos2 kernel. coeffs = 2.0 * sin(coeffs) * sin(coeffs / 2.0) / (coeffs * coeffs); // Normalize. coeffs /= dot(coeffs, vec4(1.0)); // Calculate the effective colour of the current and next // scanlines at the horizontal location of the current pixel, // using the Lanczos coefficients above. vec4 col = clamp(mul(coeffs, mat4x4( TEX2D(xy + vec2(-one.x, 0.0)), TEX2D(xy), TEX2D(xy + vec2(one.x, 0.0)), TEX2D(xy + vec2(2.0 * one.x, 0.0)))), 0.0, 1.0); vec4 col2 = clamp(mul(coeffs, mat4x4( TEX2D(xy + vec2(-one.x, one.y)), TEX2D(xy + vec2(0.0, one.y)), TEX2D(xy + one), TEX2D(xy + vec2(2.0 * one.x, one.y)))), 0.0, 1.0); #ifndef LINEAR_PROCESSING col = pow(col , vec4(CRTgamma)); col2 = pow(col2, vec4(CRTgamma)); #endif // Calculate the influence of the current and next scanlines on // the current pixel. vec4 weights = scanlineWeights(uv_ratio.y, col); vec4 weights2 = scanlineWeights(1.0 - uv_ratio.y, col2); #ifdef OVERSAMPLE uv_ratio.y =uv_ratio.y+1.0/3.0*os_filter; weights = (weights+scanlineWeights(uv_ratio.y, col))/3.0; weights2=(weights2+scanlineWeights(abs(1.0-uv_ratio.y), col2))/3.0; uv_ratio.y =uv_ratio.y-2.0/3.0*os_filter; weights=weights+scanlineWeights(abs(uv_ratio.y), col)/3.0; weights2=weights2+scanlineWeights(abs(1.0-uv_ratio.y), col2)/3.0; #endif vec3 mul_res = (col * weights + col2 * weights2).rgb; #ifdef MULTIPASS mul_res += pow(texture(Source, xy2).rgb, vec3(monitorgamma))*0.1; #endif mul_res *= vec3(cval); // dot-mask emulation: // Output pixels are alternately tinted green and magenta. #ifdef DOTMASK vec3 dotMaskWeights = mix( vec3(1.0, 0.7, 1.0), vec3(0.7, 1.0, 0.7), floor(mod(mod_factor, 2.0)) ); #else vec3 dotMaskWeights = mix( vec3(1.0, 1.0, 1.0), vec3(1.0, 1.0, 1.0), floor(mod(mod_factor, 2.0))); #endif mul_res *= dotMaskWeights; // Convert the image gamma for display on our output device. mul_res = pow(mul_res, vec3(1.0 / monitorgamma)); // Color the texel. FragColor = vec4(mul_res, 1.0); }