(handheld) Update colour correction shaders (taken from Pokefan531's latest shader pack:

https://forums.libretro.com/t/real-gba-and-ds-phat-colors/1540/174)

handheld/shaders/color/gba-color.slang

@@ -21,7 +21,7 @@ layout(std140, set = 0, binding = 0) uniform UBO
 */
 // Shader that replicates the LCD dynamics from a GameBoy Advance
 
-#pragma parameter darken_screen "Darken Screen" 0.5 -0.25 2.0 0.05
+#pragma parameter darken_screen "Darken Screen" 0.5 -0.25 1.5 0.05
 
 #define target_gamma 2.2
 #define display_gamma 2.2
@@ -31,14 +31,14 @@ layout(std140, set = 0, binding = 0) uniform UBO
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.845
-#define g 0.68
-#define b 0.755
-#define rg 0.09
-#define rb 0.16
-#define gr 0.17
-#define gb 0.085
-#define br -0.015
+#define r 0.86
+#define g 0.66
+#define b 0.81
+#define rg 0.11
+#define rb 0.1325
+#define gr 0.19
+#define gb 0.0575
+#define br -0.05
 #define bg 0.23
 #define overscan_percent_x 0.0
 #define overscan_percent_y 0.0

handheld/shaders/color/gbc-color.slang

@@ -1,18 +1,8 @@
 #version 450
 
-/*
-   GBC Color Correction Shader
-   A shader that replicates the LCD dynamics from a Game Boy Color
-   Color values are derived from Gambatte's color correction implementation, with some tweaks.
-
-   Based on Color Mangler
-   Author: hunterk
-   License: Public domain
-*/
-
 layout(push_constant) uniform Push
 {
-   float darken_screen;
+   float brighten_screen;
 } params;
 
 layout(std140, set = 0, binding = 0) uniform UBO
@@ -23,22 +13,33 @@ layout(std140, set = 0, binding = 0) uniform UBO
    vec4 SourceSize;
 } global;
 
-#pragma parameter darken_screen "Darken Screen" 0.0 -0.25 2.0 0.05
+/*
+   Shader Modified: Pokefan531
+   Color Mangler
+   Author: hunterk
+   License: Public domain
+*/
+// Shader that replicates the LCD dynamics from a GameBoy Advance
+
+#pragma parameter brighten_screen "Brighten Screen" 0.5 -0.25 1.2 0.05
 
 #define target_gamma 2.2
 #define display_gamma 2.2
+#define sat 1.0
+#define lum 1.0
+#define contrast 1.0
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.78824
-#define g 0.72941
-#define b 0.82
-#define rg 0.025
-#define rb 0.12039
-#define gr 0.12157
-#define gb 0.12157
-#define br 0.0
-#define bg 0.275000
+#define r 0.87
+#define g 0.66
+#define b 0.79
+#define rg 0.115
+#define rb 0.14
+#define gr 0.18
+#define gb 0.07
+#define br -0.05
+#define bg 0.225
 
 #pragma stage vertex
 layout(location = 0) in vec4 Position;
@@ -58,14 +59,22 @@ layout(set = 0, binding = 2) uniform sampler2D Source;
 
 void main()
 {
-   vec4 screen = pow(texture(Source, vTexCoord), vec4(target_gamma + params.darken_screen)).rgba;
+   vec4 screen = pow(texture(Source, vTexCoord), vec4(target_gamma + (params.brighten_screen * -1.0))).rgba;
+   vec4 avglum = vec4(0.5);
+   screen = mix(screen, avglum, (1.0 - contrast));
    
-   //                red   green  blue  alpha ; alpha does nothing for our purposes
-   mat4 color = mat4(r,    rg,    rb,   0.0,    //red
-                     gr,   g,     gb,   0.0,    //green
-                     br,   bg,    b,    0.0,    //blue
-                     blr,  blg,   blb,  0.0);   //black
-                 
-   screen = color * screen;
-   FragColor = pow(screen, vec4(1.0 / display_gamma));
+ //				r   g    b   black
+mat4 color = mat4(r,  rg,  rb, 0.0,  //red channel
+			   gr,  g,   gb, 0.0,  //green channel
+			   br,  bg,  b,  0.0,  //blue channel
+			  blr, blg, blb,    0.0); //alpha channel; these numbers do nothing for our purposes.
+			  
+mat4 adjust = mat4((1.0 - sat) * 0.3086 + sat, (1.0 - sat) * 0.3086, (1.0 - sat) * 0.3086, 1.0,
+(1.0 - sat) * 0.6094, (1.0 - sat) * 0.6094 + sat, (1.0 - sat) * 0.6094, 1.0,
+(1.0 - sat) * 0.0820, (1.0 - sat) * 0.0820, (1.0 - sat) * 0.0820 + sat, 1.0,
+0.0, 0.0, 0.0, 1.0);
+	color *= adjust;
+	screen = clamp(screen * lum, 0.0, 1.0);
+	screen = color * screen;
+	FragColor = pow(screen, vec4(1.0 / (display_gamma)));
 }

handheld/shaders/color/nds-color.slang

@@ -24,15 +24,15 @@ layout(std140, set = 0, binding = 0) uniform UBO
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.83
-#define g 0.65
-#define b 0.765
-#define rg 0.105
-#define rb 0.105
+#define r 0.85
+#define g 0.655
+#define b 0.865
+#define rg 0.095
+#define rb 0.06
 #define gr 0.20
-#define gb 0.13
-#define br -0.03
-#define bg 0.245
+#define gb 0.075
+#define br -0.05
+#define bg 0.25
 #define overscan_percent_x 0.0
 #define overscan_percent_y 0.0
 

handheld/shaders/color/palm-color.slang

@@ -31,14 +31,14 @@ layout(std140, set = 0, binding = 0) uniform UBO
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.745
+#define r 0.88
 #define g 0.69
-#define b 0.775
+#define b 0.765
 #define rg 0.06
 #define rb 0.085
-#define gr 0.315
-#define gb 0.14
-#define br -0.06
+#define gr 0.24
+#define gb 0.15
+#define br -0.12
 #define bg 0.25
 #define overscan_percent_x 0.0
 #define overscan_percent_y 0.0

handheld/shaders/color/psp-color.slang

@@ -24,15 +24,15 @@ layout(std140, set = 0, binding = 0) uniform UBO
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.92
+#define r 0.98
 #define g 0.795
-#define b 0.975
-#define rg 0.035
+#define b 0.98
+#define rg 0.04
 #define rb 0.01
-#define gr 0.24
-#define gb 0.015
-#define br -0.16
-#define bg 0.17
+#define gr 0.20
+#define gb 0.01
+#define br -0.18
+#define bg 0.165
 #define overscan_percent_x 0.0
 #define overscan_percent_y 0.0
 

handheld/shaders/color/vba-color.slang

@@ -31,12 +31,12 @@ layout(std140, set = 0, binding = 0) uniform UBO
 #define blr 0.0
 #define blg 0.0
 #define blb 0.0
-#define r 0.74
-#define g 0.68
-#define b 0.68
-#define rg 0.08
-#define rb 0.08
-#define gr 0.26
+#define r 0.73
+#define g 0.675
+#define b 0.675
+#define rg 0.085
+#define rb 0.085
+#define gr 0.27
 #define gb 0.24
 #define br 0.0
 #define bg 0.24

presets/retro-v2+gbc-color.slangp

@@ -9,6 +9,6 @@ scale0 = "1.000000"
 
 filter_linear1 = "false"
 
-parameters = "darken_screen;RETRO_PIXEL_SIZE"
-darken_screen = "0.500000"
+parameters = "brighten_screen;RETRO_PIXEL_SIZE"
+brighten_screen = "0.500000"
 RETRO_PIXEL_SIZE = "0.840000"