1#version 450
2
3layout(push_constant) uniform Push
4{
5    float hardScan;
6    float hardPix;
7    float warpX;
8    float warpY;
9    float maskDark;
10    float maskLight;
11    float scaleInLinearGamma;
12    float shadowMask;
13    float brightBoost;
14    float hardBloomScan;
15    float hardBloomPix;
16    float bloomAmount;
17    float shape;
18} param;
19
20#pragma parameter hardScan "hardScan" -8.0 -20.0 0.0 1.0
21#pragma parameter hardPix "hardPix" -3.0 -20.0 0.0 1.0
22#pragma parameter warpX "warpX" 0.031 0.0 0.125 0.01
23#pragma parameter warpY "warpY" 0.041 0.0 0.125 0.01
24#pragma parameter maskDark "maskDark" 0.5 0.0 2.0 0.1
25#pragma parameter maskLight "maskLight" 1.5 0.0 2.0 0.1
26#pragma parameter scaleInLinearGamma "scaleInLinearGamma" 1.0 0.0 1.0 1.0
27#pragma parameter shadowMask "shadowMask" 3.0 0.0 4.0 1.0
28#pragma parameter brightBoost "brightness boost" 1.0 0.0 2.0 0.05
29#pragma parameter hardBloomPix "bloom-x soft" -1.5 -2.0 -0.5 0.1
30#pragma parameter hardBloomScan "bloom-y soft" -2.0 -4.0 -1.0 0.1
31#pragma parameter bloomAmount "bloom amount" 0.4 0.0 1.0 0.05
32#pragma parameter shape "filter kernel shape" 2.0 0.0 10.0 0.05
33
34layout(std140, set = 0, binding = 0) uniform UBO
35{
36   mat4 MVP;
37   vec4 OutputSize;
38   vec4 OriginalSize;
39   vec4 SourceSize;
40} global;
41
42#pragma stage vertex
43layout(location = 0) in vec4 Position;
44layout(location = 1) in vec2 TexCoord;
45layout(location = 0) out vec2 vTexCoord;
46
47void main()
48{
49    gl_Position = global.MVP * Position;
50    vTexCoord = TexCoord;
51}
52
53// PUBLIC DOMAIN CRT STYLED SCAN-LINE SHADER
54//
55//   by Timothy Lottes
56//
57// This is more along the style of a really good CGA arcade monitor.
58// With RGB inputs instead of NTSC.
59// The shadow mask example has the mask rotated 90 degrees for less chromatic aberration.
60//
61// Left it unoptimized to show the theory behind the algorithm.
62//
63// It is an example what I personally would want as a display option for pixel art games.
64// Please take and use, change, or whatever.
65
66#pragma stage fragment
67layout(location = 0) in vec2 vTexCoord;
68layout(location = 1) in vec2 FragCoord;
69layout(location = 0) out vec4 FragColor;
70layout(set = 0, binding = 2) uniform sampler2D Source;
71layout(set = 0, binding = 3) uniform sampler2D ORIG_LINEARIZED;
72
73//Uncomment to reduce instructions with simpler linearization
74//(fixes HD3000 Sandy Bridge IGP)
75#define SIMPLE_LINEAR_GAMMA
76#define DO_BLOOM 1
77
78// ------------- //
79
80// sRGB to Linear.
81// Assuming using sRGB typed textures this should not be needed.
82#ifdef SIMPLE_LINEAR_GAMMA
83float ToLinear1(float c)
84{
85    return c;
86}
87vec3 ToLinear(vec3 c)
88{
89    return c;
90}
91vec3 ToSrgb(vec3 c)
92{
93    return pow(c, vec3(1.0 / 2.2));
94}
95#else
96float ToLinear1(float c)
97{
98    if (param.scaleInLinearGamma == 0)
99        return c;
100
101    return(c<=0.04045) ? c/12.92 : pow((c + 0.055)/1.055, 2.4);
102}
103
104vec3 ToLinear(vec3 c)
105{
106    if (param.scaleInLinearGamma==0)
107        return c;
108
109    return vec3(ToLinear1(c.r), ToLinear1(c.g), ToLinear1(c.b));
110}
111
112// Linear to sRGB.
113// Assuming using sRGB typed textures this should not be needed.
114float ToSrgb1(float c)
115{
116    if (param.scaleInLinearGamma == 0)
117        return c;
118
119    return(c<0.0031308 ? c*12.92 : 1.055*pow(c, 0.41666) - 0.055);
120}
121
122vec3 ToSrgb(vec3 c)
123{
124    if (param.scaleInLinearGamma == 0)
125        return c;
126
127    return vec3(ToSrgb1(c.r), ToSrgb1(c.g), ToSrgb1(c.b));
128}
129#endif
130
131
132
133// Nearest emulated sample given floating point position and texel offset.
134// Also zero's off screen.
135vec3 Fetch(vec2 pos,vec2 off){
136  pos=(floor(pos*global.SourceSize.xy+off)+vec2(0.5,0.5))/global.SourceSize.xy;
137#ifdef SIMPLE_LINEAR_GAMMA
138  return ToLinear(param.brightBoost * (texture(ORIG_LINEARIZED,pos.xy).rgb));
139#else
140  return ToLinear(param.brightBoost * texture(ORIG_LINEARIZED,pos.xy).rgb);
141#endif
142}
143
144// Distance in emulated pixels to nearest texel.
145vec2 Dist(vec2 pos)
146{
147    pos = pos*global.SourceSize.xy;
148
149    return -((pos - floor(pos)) - vec2(0.5));
150}
151
152// 1D Gaussian.
153float Gaus(float pos, float scale)
154{
155    return exp2(scale*pow(abs(pos), param.shape));
156}
157
158// 3-tap Gaussian filter along horz line.
159vec3 Horz3(vec2 pos, float off)
160{
161    vec3 b    = Fetch(pos, vec2(-1.0, off));
162    vec3 c    = Fetch(pos, vec2( 0.0, off));
163    vec3 d    = Fetch(pos, vec2( 1.0, off));
164    float dst = Dist(pos).x;
165
166    // Convert distance to weight.
167    float scale = param.hardPix;
168    float wb = Gaus(dst-1.0,scale);
169    float wc = Gaus(dst+0.0,scale);
170    float wd = Gaus(dst+1.0,scale);
171
172    // Return filtered sample.
173    return (b*wb+c*wc+d*wd)/(wb+wc+wd);
174}
175
176// 5-tap Gaussian filter along horz line.
177vec3 Horz5(vec2 pos,float off){
178    vec3 a = Fetch(pos,vec2(-2.0, off));
179    vec3 b = Fetch(pos,vec2(-1.0, off));
180    vec3 c = Fetch(pos,vec2( 0.0, off));
181    vec3 d = Fetch(pos,vec2( 1.0, off));
182    vec3 e = Fetch(pos,vec2( 2.0, off));
183
184    float dst = Dist(pos).x;
185    // Convert distance to weight.
186    float scale = param.hardPix;
187    float wa = Gaus(dst - 2.0, scale);
188    float wb = Gaus(dst - 1.0, scale);
189    float wc = Gaus(dst + 0.0, scale);
190    float wd = Gaus(dst + 1.0, scale);
191    float we = Gaus(dst + 2.0, scale);
192
193    // Return filtered sample.
194    return (a*wa+b*wb+c*wc+d*wd+e*we)/(wa+wb+wc+wd+we);
195}
196
197// 7-tap Gaussian filter along horz line.
198vec3 Horz7(vec2 pos,float off)
199{
200    vec3 a = Fetch(pos, vec2(-3.0, off));
201    vec3 b = Fetch(pos, vec2(-2.0, off));
202    vec3 c = Fetch(pos, vec2(-1.0, off));
203    vec3 d = Fetch(pos, vec2( 0.0, off));
204    vec3 e = Fetch(pos, vec2( 1.0, off));
205    vec3 f = Fetch(pos, vec2( 2.0, off));
206    vec3 g = Fetch(pos, vec2( 3.0, off));
207
208    float dst = Dist(pos).x;
209    // Convert distance to weight.
210    float scale = param.hardBloomPix;
211    float wa = Gaus(dst - 3.0, scale);
212    float wb = Gaus(dst - 2.0, scale);
213    float wc = Gaus(dst - 1.0, scale);
214    float wd = Gaus(dst + 0.0, scale);
215    float we = Gaus(dst + 1.0, scale);
216    float wf = Gaus(dst + 2.0, scale);
217    float wg = Gaus(dst + 3.0, scale);
218
219    // Return filtered sample.
220    return (a*wa+b*wb+c*wc+d*wd+e*we+f*wf+g*wg)/(wa+wb+wc+wd+we+wf+wg);
221}
222
223// Return scanline weight.
224float Scan(vec2 pos, float off)
225{
226    float dst = Dist(pos).y;
227
228    return Gaus(dst + off, param.hardScan);
229}
230
231// Return scanline weight for bloom.
232float BloomScan(vec2 pos, float off)
233{
234    float dst = Dist(pos).y;
235
236    return Gaus(dst + off, param.hardBloomScan);
237}
238
239// Allow nearest three lines to effect pixel.
240vec3 Tri(vec2 pos)
241{
242    vec3 a = Horz3(pos,-1.0);
243    vec3 b = Horz5(pos, 0.0);
244    vec3 c = Horz3(pos, 1.0);
245
246    float wa = Scan(pos,-1.0);
247    float wb = Scan(pos, 0.0);
248    float wc = Scan(pos, 1.0);
249
250    return a*wa + b*wb + c*wc;
251}
252
253// Small bloom.
254vec3 Bloom(vec2 pos)
255{
256    vec3 a = Horz5(pos,-2.0);
257    vec3 b = Horz7(pos,-1.0);
258    vec3 c = Horz7(pos, 0.0);
259    vec3 d = Horz7(pos, 1.0);
260    vec3 e = Horz5(pos, 2.0);
261
262    float wa = BloomScan(pos,-2.0);
263    float wb = BloomScan(pos,-1.0);
264    float wc = BloomScan(pos, 0.0);
265    float wd = BloomScan(pos, 1.0);
266    float we = BloomScan(pos, 2.0);
267
268    return a*wa+b*wb+c*wc+d*wd+e*we;
269}
270
271// Distortion of scanlines, and end of screen alpha.
272vec2 Warp(vec2 pos)
273{
274    pos  = pos*2.0-1.0;
275    pos *= vec2(1.0 + (pos.y*pos.y)*param.warpX, 1.0 + (pos.x*pos.x)*param.warpY);
276
277    return pos*0.5 + 0.5;
278}
279
280// Shadow mask.
281vec3 Mask(vec2 pos)
282{
283    vec3 mask = vec3(param.maskDark, param.maskDark, param.maskDark);
284
285    // Very compressed TV style shadow mask.
286    if (param.shadowMask == 1.0)
287    {
288        float line = param.maskLight;
289        float odd = 0.0;
290
291        if (fract(pos.x*0.166666666) < 0.5) odd = 1.0;
292        if (fract((pos.y + odd) * 0.5) < 0.5) line = param.maskDark;
293
294        pos.x = fract(pos.x*0.333333333);
295
296        if      (pos.x < 0.333) mask.r = param.maskLight;
297        else if (pos.x < 0.666) mask.g = param.maskLight;
298        else                    mask.b = param.maskLight;
299        mask*=line;
300    }
301
302    // Aperture-grille.
303    else if (param.shadowMask == 2.0)
304    {
305        pos.x = fract(pos.x*0.333333333);
306
307        if      (pos.x < 0.333) mask.r = param.maskLight;
308        else if (pos.x < 0.666) mask.g = param.maskLight;
309        else                    mask.b = param.maskLight;
310    }
311
312    // Stretched VGA style shadow mask (same as prior shaders).
313    else if (param.shadowMask == 3.0)
314    {
315        pos.x += pos.y*3.0;
316        pos.x  = fract(pos.x*0.166666666);
317
318        if      (pos.x < 0.333) mask.r = param.maskLight;
319        else if (pos.x < 0.666) mask.g = param.maskLight;
320        else                    mask.b = param.maskLight;
321    }
322
323    // VGA style shadow mask.
324    else if (param.shadowMask == 4.0)
325    {
326        pos.xy  = floor(pos.xy*vec2(1.0, 0.5));
327        pos.x  += pos.y*3.0;
328        pos.x   = fract(pos.x*0.166666666);
329
330        if      (pos.x < 0.333) mask.r = param.maskLight;
331        else if (pos.x < 0.666) mask.g = param.maskLight;
332        else                    mask.b = param.maskLight;
333    }
334
335    return mask;
336}
337
338void main()
339{
340    vec2 pos = vTexCoord;
341
342    FragColor = vec4(Bloom(pos)*param.bloomAmount, 1.0);
343}
344