add crt-potato-BVM (#400)

* add crt-potato-BVM

crt/crt-potato-BVM.slangp

@@ -0,0 +1,19 @@
+shaders = "1"
+
+shader0 = shaders/crt-potato/shader-files/ultra_potato.slang
+filter_linear0 = "false"
+wrap_mode0 = "clamp_to_border"
+mipmap_input0 = "false"
+alias0 = "PASS0"
+float_framebuffer0 = "false"
+srgb_framebuffer0 = "false"
+scale_type_x0 = "viewport"
+scale_x0 = "1.000000"
+scale_type_y0 = "viewport"
+scale_y0 = "1.000000"
+
+textures = "MASK"
+MASK = shaders/crt-potato/resources/mask1.png
+MASK_wrap_mode = "clamp_to_border"
+MASK_linear = "true"
+MASK_mipmap = "false"

crt/shaders/crt-potato/shader-files/ultra_potato.slang

@@ -0,0 +1,57 @@
+#version 450
+
+// crt-potato mod by DariusG
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+} params;
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} global;
+
+// Largest integer scale of input video that will fit in the current output (y axis would typically be limiting on widescreens)
+#define video_scale         floor(params.OutputSize.y * params.SourceSize.w)
+
+#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 dot_size;
+layout(location = 2) out vec2 one_texel;
+
+void main()
+{
+	gl_Position = global.MVP * Position;
+	vTexCoord = TexCoord;
+	dot_size = params.SourceSize.zw;
+	one_texel = 1.0 / (params.SourceSize.xy * video_scale);
+}
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 1) in vec2 dot_size;
+layout(location = 2) in vec2 one_texel;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+layout(set = 0, binding = 3) uniform sampler2D MASK;
+
+
+#define maskSize vec2(2., floor(params.OutputSize.y / params.SourceSize.y + 0.000001))
+
+void main()
+{
+   vec4 res =texture(Source, vTexCoord);
+   float lum = max((res.r,res.g),res.b); 
+   lum = mix(1.0,0.3,lum);
+   vec4 mask = texture(MASK, fract((vTexCoord.xy * params.OutputSize.xy) / maskSize));
+   mask = pow(mask,vec4(lum));
+   res *= mix(1.0,1.2,lum);
+   vec4 color = mask * res; 
+   FragColor = color;
+}