// license:BSD-3-Clause // copyright-holders:ImJezze //----------------------------------------------------------------------------- // Distortion Effect //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- // Sampler Definitions //----------------------------------------------------------------------------- texture DiffuseTexture; sampler DiffuseSampler = sampler_state { Texture = ; MipFilter = LINEAR; MinFilter = LINEAR; MagFilter = LINEAR; AddressU = CLAMP; AddressV = CLAMP; AddressW = CLAMP; }; //----------------------------------------------------------------------------- // Vertex Definitions //----------------------------------------------------------------------------- struct VS_INPUT { float4 Position : POSITION; float4 Color : COLOR0; float2 TexCoord : TEXCOORD0; }; struct VS_OUTPUT { float4 Position : POSITION; float4 Color : COLOR0; float2 TexCoord : TEXCOORD0; }; struct PS_INPUT { float4 Color : COLOR0; float2 TexCoord : TEXCOORD0; }; //----------------------------------------------------------------------------- // Constants //----------------------------------------------------------------------------- static const float Epsilon = 1.0e-7f; static const float PI = 3.1415927f; static const float E = 2.7182817f; static const float Gelfond = 23.140692f; // e^pi (Gelfond constant) static const float GelfondSchneider = 2.6651442f; // 2^sqrt(2) (Gelfond-Schneider constant) //----------------------------------------------------------------------------- // Functions //----------------------------------------------------------------------------- // www.stackoverflow.com/questions/5149544/can-i-generate-a-random-number-inside-a-pixel-shader/ float random(float2 seed) { // irrationals for pseudo randomness float2 i = float2(Gelfond, GelfondSchneider); return frac(cos(dot(seed, i)) * 123456.0f); } // www.dinodini.wordpress.com/2010/04/05/normalized-tunable-sigmoid-functions/ float normalizedSigmoid(float n, float k) { // valid for n and k in range of -1.0 and 1.0 return (n - n * k) / (k - abs(n) * 2.0f * k + 1); } // www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float roundBox(float2 p, float2 b, float r) { return length(max(abs(p) - b + r, 0.0f)) - r; } //----------------------------------------------------------------------------- // Distortion Vertex Shader //----------------------------------------------------------------------------- uniform float2 ScreenDims; // size of the window or fullscreen uniform float2 TargetDims; // size of the target surface uniform float2 QuadDims; // size of the screen quad VS_OUTPUT vs_main(VS_INPUT Input) { VS_OUTPUT Output = (VS_OUTPUT)0; Output.Position = float4(Input.Position.xyz, 1.0f); Output.Position.xy /= ScreenDims; Output.Position.y = 1.0f - Output.Position.y; // flip y Output.Position.xy -= 0.5f; // center Output.Position.xy *= 2.0f; // zoom Output.Color = Input.Color; Output.TexCoord = Input.Position.xy / ScreenDims; Output.TexCoord += 0.5f / TargetDims; // half texel offset correction (DX9) return Output; } //----------------------------------------------------------------------------- // Distortion Pixel Shader //----------------------------------------------------------------------------- uniform float CurvatureAmount = 0.0f; uniform float RoundCornerAmount = 0.0f; uniform float SmoothBorderAmount = 0.0f; uniform float VignettingAmount = 0.0f; uniform float ReflectionAmount = 0.0f; uniform int RotationType = 0; // 0 = 0°, 1 = 90°, 2 = 180°, 3 = 270° float2 GetScreenQuadRatio() { float ScreenRatio = ScreenDims.x / ScreenDims.y; float QuadRatio = QuadDims.x / QuadDims.y; float ScreenQuadRatio = QuadRatio / ScreenRatio; return ScreenQuadRatio > 1.0f ? float2(1.0, 1.0f / ScreenQuadRatio) : float2(ScreenQuadRatio, 1.0); } float2 GetQuadRatio() { float QuadRatio = QuadDims.x / QuadDims.y; return QuadRatio > 1.0f ? float2 (1.0f, 1.0f / QuadRatio) : float2 (QuadRatio, 1.0f); } float GetNoiseFactor(float3 n, float random) { // smaller n become more noisy return 1.0f + random * max(0.0f, 0.25f * pow(E, -8 * n)); } float GetVignetteFactor(float2 coord, float amount) { float2 VignetteCoord = coord / (QuadDims / ScreenDims); float VignetteLength = length(VignetteCoord); float VignetteBlur = (amount * 0.75f) + 0.25; // 0.5 full screen fitting circle float VignetteRadius = 1.0f - (amount * 0.25f); float Vignette = smoothstep(VignetteRadius, VignetteRadius - VignetteBlur, VignetteLength); return saturate(Vignette); } float GetSpotAddend(float2 coord, float amount) { float2 QuadRatio = GetQuadRatio(); // upper right quadrant float2 spotOffset = RotationType == 1 // 90° ? float2(-0.25f, -0.25f) : RotationType == 2 // 180° ? float2(0.25f, -0.25f) : RotationType == 3 // 270° ? float2(0.25f, 0.25f) : float2(-0.25f, 0.25f); float2 SpotCoord = coord / (QuadDims / ScreenDims); SpotCoord += spotOffset * QuadRatio; SpotCoord *= QuadRatio; float SpotBlur = amount; // 0.5 full screen fitting circle float SpotRadius = amount * 0.75f; float Spot = smoothstep(SpotRadius, SpotRadius - SpotBlur, length(SpotCoord)); float SigmoidSpot = amount * normalizedSigmoid(Spot, 0.75); // increase strength by 100% SigmoidSpot = SigmoidSpot * 2.0f; return saturate(SigmoidSpot); } float GetRoundCornerFactor(float2 coord, float radiusAmount, float smoothAmount) { float2 ScreenQuadRatio = GetScreenQuadRatio(); // reduce smooth amount down to radius amount smoothAmount = min(smoothAmount, radiusAmount); float range = min(QuadDims.x, QuadDims.y) * 0.5; float radius = range * max(radiusAmount, 0.0025f); float smooth = 1.0 / (range * max(smoothAmount, 0.0025f)); // compute box float box = roundBox(ScreenDims * (coord * 2.0f), ScreenDims * ScreenQuadRatio, radius); // apply smooth box *= smooth; box += 1.0f - pow(smooth * 0.5f, 0.5f); float border = smoothstep(1.0f, 0.0f, box); return saturate(border); } // www.francois-tarlier.com/blog/cubic-lens-distortion-shader/ float2 GetDistortedCoords(float2 centerCoord, float amount) { // lens distortion coefficient float k = amount; // cubic distortion value float kcube = amount * 2.0f; // compute cubic distortion factor float r2 = centerCoord.x * centerCoord.x + centerCoord.y * centerCoord.y; float f = kcube == 0.0f ? 1.0f + r2 * k : 1.0f + r2 * (k + kcube * sqrt(r2)); // fit screen bounds f /= 1.0f + amount * 0.5f; // apply cubic distortion factor centerCoord *= f; return centerCoord; } float2 GetCoords(float2 coord, float distortionAmount) { float2 ScreenQuadRatio = GetScreenQuadRatio(); // center coordinates coord -= 0.5f; // apply ratio difference between screen and quad coord /= ScreenQuadRatio; // distort coordinates coord = GetDistortedCoords(coord, distortionAmount); // revert ratio difference between screen and quad coord *= ScreenQuadRatio; // un-center coordinates coord += 0.5f; return coord; } float4 ps_main(PS_INPUT Input) : COLOR { // Screen Curvature float2 TexCoord = GetCoords(Input.TexCoord, CurvatureAmount * 0.25f); // reduced amount float2 TexCoordCentered = TexCoord; TexCoordCentered -= 0.5f; // Color float4 BaseColor = tex2D(DiffuseSampler, TexCoord); BaseColor.a = 1.0f; // Vignetting Simulation float2 VignetteCoord = TexCoordCentered; float VignetteFactor = GetVignetteFactor(VignetteCoord, VignettingAmount); BaseColor.rgb *= VignetteFactor; // Light Reflection Simulation float3 LightColor = float3(1.0f, 0.90f, 0.80f); // color temperature 5.000 Kelvin float2 SpotCoord = TexCoordCentered; float2 NoiseCoord = TexCoordCentered; float SpotAddend = GetSpotAddend(SpotCoord, ReflectionAmount); float NoiseFactor = GetNoiseFactor(SpotAddend, random(NoiseCoord)); BaseColor.rgb += SpotAddend * NoiseFactor * LightColor; // Round Corners Simulation float2 RoundCornerCoord = TexCoordCentered; float roundCornerFactor = GetRoundCornerFactor(RoundCornerCoord, RoundCornerAmount, SmoothBorderAmount); BaseColor.rgb *= roundCornerFactor; return BaseColor; } //----------------------------------------------------------------------------- // Distortion Technique //----------------------------------------------------------------------------- technique DefaultTechnique { pass Pass0 { Lighting = FALSE; VertexShader = compile vs_3_0 vs_main(); PixelShader = compile ps_3_0 ps_main(); } }