More math adjustments to shaders + new shader

dist/post_shaders/Bloom.fx

@@ -24,15 +24,7 @@ uniform float Amount <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Blur.fx

@@ -33,37 +33,10 @@ uniform float FocusSoftness <
 > = 0.4;
 
 static const int TAPS = 17;
-static const float3 KERNEL[17] = {
-    float3( 0.171499,  0.000000, 0.942873),
-    float3(-0.219031,  0.200651, 0.838223),
-    float3( 0.033526, -0.382014, 0.745189),
-    float3( 0.276075,  0.360090, 0.662480),
-    float3(-0.506631, -0.089616, 0.588951),
-    float3( 0.479925, -0.305289, 0.523583),
-    float3(-0.160526,  0.597147, 0.465471),
-    float3(-0.306140, -0.589453, 0.413808),
-    float3( 0.664200,  0.242565, 0.367879),
-    float3(-0.690990,  0.285231, 0.327048),
-    float3( 0.333103, -0.711821, 0.290749),
-    float3( 0.246154,  0.784779, 0.258479),
-    float3(-0.741912, -0.429953, 0.229790),
-    float3( 0.870348, -0.191344, 0.204286),
-    float3(-0.531160,  0.755520, 0.181612),
-    float3(-0.122710, -0.946946, 0.161455),
-    float3( 0.753320,  0.634899, 0.143535)
-};
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 
@@ -79,17 +52,22 @@ float4 PS_Blur(float4 pos : SV_Position, float2 uv : TEXCOORD) : SV_Target
     float amount = Strength * focus;
 
     float angle = frac(sin(dot(pos.xy, float2(12.9898, 78.233))) * 43758.5453) * 6.2831853;
-    float2 rotation = float2(cos(angle), sin(angle));
+    float2 spoke = float2(cos(angle), sin(angle));
+
+    const float2 turn = float2(cos(2.39996323), sin(2.39996323));
+    const float decay = exp(-2.0 / float(TAPS));
+    float weight = exp(-1.0 / float(TAPS));
 
     float3 sum = float3(0.0, 0.0, 0.0);
     float total = 0.0;
     for (int i = 0; i < TAPS; ++i)
     {
-        float3 tap = KERNEL[i];
-        float2 spun = float2(tap.x * rotation.x - tap.y * rotation.y,
-                             tap.x * rotation.y + tap.y * rotation.x);
-        sum += tex2D(BackBuffer, uv + spun * texel * Radius).rgb * tap.z;
-        total += tap.z;
+        float reach = sqrt((float(i) + 0.5) / float(TAPS));
+        sum += tex2D(BackBuffer, uv + spoke * reach * texel * Radius).rgb * weight;
+        total += weight;
+        weight *= decay;
+        spoke = float2(spoke.x * turn.x - spoke.y * turn.y,
+                       spoke.x * turn.y + spoke.y * turn.x);
     }
 
     float3 blurred = sum / total;

dist/post_shaders/CRT.fx

@@ -33,15 +33,7 @@ uniform float Bleed <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Cartoon.fx

@@ -25,15 +25,7 @@ uniform float Levels <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/CartoonSoft.fx

@@ -44,15 +44,7 @@ uniform float Saturation <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/CelShading.fx

@@ -55,15 +55,7 @@ uniform float Saturation <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/ChromaticAberration.fx

@@ -20,15 +20,7 @@ uniform float Falloff <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/ColorGrade.fx

@@ -34,15 +34,7 @@ uniform float Gamma <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Deband.fx

@@ -30,15 +30,7 @@ uniform float Grain <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Denoise.fx

@@ -27,15 +27,7 @@ uniform float Curve <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/FilmGrain.fx

@@ -26,15 +26,7 @@ uniform float Colored <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/FilmicCurve.fx

@@ -32,15 +32,7 @@ uniform float Amount <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/LensDistortion.fx

@@ -20,15 +20,7 @@ uniform float Zoom <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Levels.fx

@@ -38,15 +38,7 @@ uniform float OutputWhite <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/MotionBlur.fx

@@ -0,0 +1,88 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+texture BackBufferTex : COLOR;
+sampler BackBuffer { Texture = BackBufferTex; };
+
+uniform float Length <
+    ui_type = "slider";
+    ui_label = "Length";
+    ui_tooltip = "How far the streaks reach, as a percentage of screen height.";
+    ui_min = 0.0; ui_max = 20.0; ui_step = 0.5;
+> = 5.0;
+
+uniform float Zoom <
+    ui_type = "slider";
+    ui_label = "Zoom";
+    ui_tooltip = "Streaks running out from the centre of the screen, as if rushing forward. The centre stays sharp.";
+    ui_min = 0.0; ui_max = 1.0; ui_step = 0.05;
+> = 1.0;
+
+uniform float Pan <
+    ui_type = "slider";
+    ui_label = "Pan";
+    ui_tooltip = "Streaks running in one fixed direction, as if the camera were sweeping across.";
+    ui_min = 0.0; ui_max = 1.0; ui_step = 0.05;
+> = 0.0;
+
+uniform float Angle <
+    ui_type = "slider";
+    ui_label = "Pan Angle";
+    ui_tooltip = "Direction of the sweep, in degrees.";
+    ui_min = 0.0; ui_max = 360.0; ui_step = 5.0;
+> = 0.0;
+
+uniform float Spin <
+    ui_type = "slider";
+    ui_label = "Spin";
+    ui_tooltip = "Streaks curling around the centre, as if the camera were rolling. Negative turns the other way.";
+    ui_min = -1.0; ui_max = 1.0; ui_step = 0.05;
+> = 0.0;
+
+static const int TAPS = 24;
+
+void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
+{
+    uv = float2(float(id & 2), float((id & 1) << 1));
+    pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
+}
+
+float4 PS_MotionBlur(float4 pos : SV_Position, float2 uv : TEXCOORD) : SV_Target
+{
+    float aspect = BUFFER_WIDTH * BUFFER_RCP_HEIGHT;
+    float2 to_screen = float2(aspect, 1.0);
+
+    float2 centred = (uv - 0.5) * to_screen * 2.0;
+    float2 outward = centred;
+    float2 around = float2(-centred.y, centred.x);
+
+    float radians_angle = Angle * 0.01745329;
+    float2 sweep = float2(cos(radians_angle), sin(radians_angle));
+
+    float2 velocity = sweep * Pan + outward * Zoom + around * Spin;
+    velocity *= Length * 0.01;
+    velocity /= to_screen;
+
+    float jitter = frac(sin(dot(pos.xy, float2(12.9898, 78.233))) * 43758.5453);
+
+    float3 sum = float3(0.0, 0.0, 0.0);
+    for (int i = 0; i < TAPS; ++i)
+    {
+        float t = (float(i) + jitter) / float(TAPS) - 0.5;
+        sum += tex2D(BackBuffer, uv + velocity * t).rgb;
+    }
+
+    return float4(sum / float(TAPS), 1.0);
+}
+
+technique MotionBlur <
+    ui_label = "Motion Blur";
+    ui_tooltip = "Camera style motion blur: streaks the picture outwards, sideways or around, without touching still detail at the centre.";
+>
+{
+    pass
+    {
+        VertexShader = VS_PostProcess;
+        PixelShader = PS_MotionBlur;
+    }
+}

dist/post_shaders/NaturalColors.fx

@@ -24,15 +24,7 @@ uniform float Chroma <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Reflections.fx

@@ -50,15 +50,7 @@ uniform float RippleSpeed <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Scanlines.fx

@@ -32,15 +32,7 @@ uniform float Tint <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Sharpen.fx

@@ -12,15 +12,7 @@ uniform float Amount <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/SplitToning.fx

@@ -37,15 +37,7 @@ uniform float Balance <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/Vignette.fx

@@ -23,15 +23,7 @@ uniform float Aspect <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }
 

dist/post_shaders/WhiteBalance.fx

@@ -20,15 +20,7 @@ uniform float Tint <
 
 void VS_PostProcess(in uint id : SV_VertexID, out float4 pos : SV_Position, out float2 uv : TEXCOORD)
 {
-    uv = float2(0.0, 0.0);
-    if (id == 2)
-    {
-        uv.x = 2.0;
-    }
-    if (id == 1)
-    {
-        uv.y = 2.0;
-    }
+    uv = float2(float(id & 2), float((id & 1) << 1));
     pos = float4(uv * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
 }