move simple scanline shaders out of misc and fix hlsl function name collision

crt/shaders/crt-slangtest/scanline.slang

@@ -33,7 +33,7 @@ void main()
 {
    vec2 tex = vTexCoord * global.SourceSize.xy;
 
-   float frac = fract(tex.y) - 0.5;
+   float fraction = fract(tex.y) - 0.5;
    tex.y = floor(tex.y) + 0.5;
    tex = tex * global.SourceSize.zw;
 
@@ -42,7 +42,7 @@ void main()
    vec3 l1 = TEX(0,  0);
    vec3 l2 = TEX(0,  1);
 
-   vec3 dist = (3.5 - 1.0 * vec3(luma(l0), luma(l1), luma(l2))) * (frac + vec3(+1.0, 0.0, -1.0));
+   vec3 dist = (3.5 - 1.0 * vec3(luma(l0), luma(l1), luma(l2))) * (fraction + vec3(+1.0, 0.0, -1.0));
    dist = exp2(-dist * dist);
 
    vec3 color =

scanlines/shaders/res-independent-scanlines.slang

@@ -0,0 +1,55 @@
+#version 450
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+   vec4 FinalViewportSize;
+	float SCANLINE_SINE_COMP_B;
+   float scanline_size;
+} params;
+
+#pragma parameter SCANLINE_SINE_COMP_B "Scanline Sine Comp B" 0.25 0.0 1.0 0.05
+#pragma parameter scanline_size "Scanline Scale" 4.0 2.0 10.0 0.5
+
+#define SCANLINE_SINE_COMP_B params.SCANLINE_SINE_COMP_B
+#define scanline_size params.scanline_size
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} global;
+
+#define pi 3.141592654
+
+#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 omega;
+
+void main()
+{
+   gl_Position = global.MVP * Position;
+   vTexCoord = TexCoord;
+   
+   omega = vec2(pi * params.OutputSize.x, 2.0 * pi * params.SourceSize.y);
+}
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 1) in vec2 omega;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+void main()
+{
+   vec2 sine_comp = vec2(0.0, SCANLINE_SINE_COMP_B);
+   vec3 res = texture(Source, vTexCoord).xyz;
+   vec2 fragcoord = vTexCoord.xy * params.FinalViewportSize.xy;
+   // picked 224 here as a magic number because it's a common 240p res and therefore a good starting point
+   vec3 scanline = res * ((1. - 0.75 * SCANLINE_SINE_COMP_B) + dot(sine_comp * sin((fragcoord / (224. * scanline_size)) * omega), vec2(1.0, 1.0)));
+   FragColor = vec4(scanline.x, scanline.y, scanline.z, 1.0);
+}

scanlines/shaders/scanline.slang

@@ -53,3 +53,4 @@ void main()
    vec3 scanline = res * (SCANLINE_BASE_BRIGHTNESS + dot(sine_comp * sin(vTexCoord * omega), vec2(1.0, 1.0)));
    FragColor = vec4(scanline.x, scanline.y, scanline.z, 1.0);
 }
+