Updated shader and fixed PNG output

shaders/fisheye-equirectangular-mirror/shader.slang

@@ -49,7 +49,7 @@ float normalizedFisheyeRadius(float theta, float halfFov)
 
 float3 equirectangularRay(float2 uv)
 {
-	float longitude = (uv.x - 0.5) * TWO_PI + radiansFromDegrees(seamAngleDegrees);
+	float longitude = (uv.x - 0.5) * TWO_PI;
 	float latitude = (0.5 - uv.y) * PI;
 	float latitudeCos = cos(latitude);
 
@@ -60,6 +60,39 @@ float3 equirectangularRay(float2 uv)
 	));
 }
 
+float sourceUvOutsideDistance(float2 uv)
+{
+	float2 lower = max(-uv, float2(0.0, 0.0));
+	float2 upper = max(uv - 1.0, float2(0.0, 0.0));
+	return max(max(lower.x, lower.y), max(upper.x, upper.y));
+}
+
+float4 sampleEdgeFilledVideo(float2 sourceUv, ShaderContext context)
+{
+	float outsideDistance = sourceUvOutsideDistance(sourceUv);
+	if (outsideDistance <= 0.0)
+		return sampleVideo(sourceUv);
+
+	float fillDistance = max(edgeFill, 0.0);
+	if (outsideDistance > fillDistance)
+		return outsideColor;
+
+	float2 clampedUv = saturate(sourceUv);
+	float2 inward = clampedUv - sourceUv;
+	float inwardLength = max(length(inward), 0.000001);
+	inward /= inwardLength;
+
+	float blurDistance = max(edgeBlur, 0.0);
+	float4 color = sampleVideo(clampedUv) * 0.32;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 0.35)) * 0.26;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 0.75)) * 0.20;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 1.20)) * 0.14;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 1.75)) * 0.08;
+
+	float edgeFade = smoothstep(fillDistance * 0.78, fillDistance, outsideDistance);
+	return lerp(color, outsideColor, edgeFade);
+}
+
 float4 shadeVideo(ShaderContext context)
 {
 	float3 ray = equirectangularRay(context.uv);
@@ -86,8 +119,9 @@ float4 shadeVideo(ShaderContext context)
 		center.y - sin(phi) * fisheyeRadius * radius.y
 	);
 
-	if (sourceUv.x < 0.0 || sourceUv.x > 1.0 || sourceUv.y < 0.0 || sourceUv.y > 1.0)
+	float2 guard = 0.5 / max(context.inputResolution, float2(1.0, 1.0));
+	if (edgeFill <= 0.0 && (sourceUv.x < -guard.x || sourceUv.x > 1.0 + guard.x || sourceUv.y < -guard.y || sourceUv.y > 1.0 + guard.y))
 		return outsideColor;
 
-	return sampleVideo(sourceUv);
+	return sampleEdgeFilledVideo(sourceUv, context);
 }