From ce6a354e121915c2925e545e7df2929492d69d50 Mon Sep 17 00:00:00 2001 From: senorblanco Date: Thu, 12 Jun 2014 11:24:19 -0700 Subject: [PATCH] Fix tiled perlin noise. It turns out that the perlin implementation we inherited from WebKit does not actually generate tileable noise (see Chromium bug http://crbug.com/383495). The main problem is that when generating coordinates for gradient interpolation, it was attempting to wrap both x and (x + 1) simultaneously at the tile boundary (that is, either both or neither are wrapped). This obviously won't work, since along the tile seams, (x + 1) should be wrapped, but x should not. The same is true in y. This patch fixes both the CPU and GPU paths, renames some variables to more closely match the spec, and modifies the perlin noise GM to actually test tiling. (Note that the clipping the GM was doing was removed, since it's superfluous: it used to be necessary for image filters, but isn't anymore, and this isn't an image filter GM anyway.) R=sugoi@google.com, sugoi TBR=senorblanco Author: senorblanco@chromium.org Review URL: https://codereview.chromium.org/332523006 --- expectations/gm/ignored-tests.txt | 4 ++ gm/perlinnoise.cpp | 33 ++++++++++------ src/effects/SkPerlinNoiseShader.cpp | 77 +++++++++++++++++++++---------------- 3 files changed, 68 insertions(+), 46 deletions(-) diff --git a/expectations/gm/ignored-tests.txt b/expectations/gm/ignored-tests.txt index 573593b..9d6ce3e 100644 --- a/expectations/gm/ignored-tests.txt +++ b/expectations/gm/ignored-tests.txt @@ -78,3 +78,7 @@ dashcubics # dandov: Fix for bitmap shader by taking into account if the bitmap is alpha only # https://codereview.chromium.org/318923005/ bitmapshaders + +# Added by senorblanco for https://codereview.chromium.org/332523006/ +# Needs rebaseline for modified test cases +perlinnoise diff --git a/gm/perlinnoise.cpp b/gm/perlinnoise.cpp index ee58f6f..b69b7d0 100644 --- a/gm/perlinnoise.cpp +++ b/gm/perlinnoise.cpp @@ -24,13 +24,11 @@ protected: return SkISize::Make(200, 500); } - void drawClippedRect(SkCanvas* canvas, int x, int y, const SkPaint& paint) { + void drawRect(SkCanvas* canvas, int x, int y, const SkPaint& paint, const SkISize& size) { canvas->save(); - canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y), - SkIntToScalar(fSize.width()), SkIntToScalar(fSize.height()))); - SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y), - SkIntToScalar(fSize.width()), - SkIntToScalar(fSize.height())); + canvas->translate(SkIntToScalar(x), SkIntToScalar(y)); + SkRect r = SkRect::MakeWH(SkIntToScalar(size.width()), + SkIntToScalar(size.height())); canvas->drawRect(r, paint); canvas->restore(); } @@ -38,14 +36,25 @@ protected: void test(SkCanvas* canvas, int x, int y, SkPerlinNoiseShader::Type type, float baseFrequencyX, float baseFrequencyY, int numOctaves, float seed, bool stitchTiles) { + SkISize tileSize = SkISize::Make(fSize.width() / 2, fSize.height() / 2); SkShader* shader = (type == SkPerlinNoiseShader::kFractalNoise_Type) ? SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves, - seed, stitchTiles ? &fSize : NULL) : + seed, stitchTiles ? &tileSize : NULL) : SkPerlinNoiseShader::CreateTurbulence(baseFrequencyX, baseFrequencyY, numOctaves, - seed, stitchTiles ? &fSize : NULL); + seed, stitchTiles ? &tileSize : NULL); SkPaint paint; paint.setShader(shader)->unref(); - drawClippedRect(canvas, x, y, paint); + if (stitchTiles) { + drawRect(canvas, x, y, paint, tileSize); + x += tileSize.width(); + drawRect(canvas, x, y, paint, tileSize); + y += tileSize.width(); + drawRect(canvas, x, y, paint, tileSize); + x -= tileSize.width(); + drawRect(canvas, x, y, paint, tileSize); + } else { + drawRect(canvas, x, y, paint, fSize); + } } virtual void onDraw(SkCanvas* canvas) { @@ -58,10 +67,10 @@ protected: test(canvas, 0, 100, SkPerlinNoiseShader::kFractalNoise_Type, 0.1f, 0.1f, 2, 0, false); test(canvas, 100, 100, SkPerlinNoiseShader::kFractalNoise_Type, - 0.2f, 0.4f, 5, 0, true); + 0.05f, 0.1f, 1, 0, true); test(canvas, 0, 200, SkPerlinNoiseShader::kTurbulence_Type, - 0.1f, 0.1f, 2, 0, true); + 0.1f, 0.1f, 1, 0, true); test(canvas, 100, 200, SkPerlinNoiseShader::kTurbulence_Type, 0.2f, 0.4f, 5, 0, false); @@ -75,7 +84,7 @@ protected: test(canvas, 0, 400, SkPerlinNoiseShader::kFractalNoise_Type, 0.1f, 0.1f, 2, 0, false); test(canvas, 100, 400, SkPerlinNoiseShader::kFractalNoise_Type, - 0.2f, 0.4f, 5, 0, true); + 0.1f, 0.05f, 1, 0, true); } private: diff --git a/src/effects/SkPerlinNoiseShader.cpp b/src/effects/SkPerlinNoiseShader.cpp index bc24061..c230c2d 100644 --- a/src/effects/SkPerlinNoiseShader.cpp +++ b/src/effects/SkPerlinNoiseShader.cpp @@ -39,9 +39,6 @@ inline int checkNoise(int noiseValue, int limitValue, int newValue) { if (noiseValue >= limitValue) { noiseValue -= newValue; } - if (noiseValue >= limitValue - 1) { - noiseValue -= newValue - 1; - } return noiseValue; } @@ -320,12 +317,14 @@ SkScalar SkPerlinNoiseShader::PerlinNoiseShaderContext::noise2D( const StitchData& stitchData, const SkPoint& noiseVector) const { struct Noise { int noisePositionIntegerValue; + int nextNoisePositionIntegerValue; SkScalar noisePositionFractionValue; Noise(SkScalar component) { SkScalar position = component + kPerlinNoise; noisePositionIntegerValue = SkScalarFloorToInt(position); noisePositionFractionValue = position - SkIntToScalar(noisePositionIntegerValue); + nextNoisePositionIntegerValue = noisePositionIntegerValue + 1; } }; Noise noiseX(noiseVector.x()); @@ -338,28 +337,36 @@ SkScalar SkPerlinNoiseShader::PerlinNoiseShaderContext::noise2D( checkNoise(noiseX.noisePositionIntegerValue, stitchData.fWrapX, stitchData.fWidth); noiseY.noisePositionIntegerValue = checkNoise(noiseY.noisePositionIntegerValue, stitchData.fWrapY, stitchData.fHeight); + noiseX.nextNoisePositionIntegerValue = + checkNoise(noiseX.nextNoisePositionIntegerValue, stitchData.fWrapX, stitchData.fWidth); + noiseY.nextNoisePositionIntegerValue = + checkNoise(noiseY.nextNoisePositionIntegerValue, stitchData.fWrapY, stitchData.fHeight); } noiseX.noisePositionIntegerValue &= kBlockMask; noiseY.noisePositionIntegerValue &= kBlockMask; - int latticeIndex = - paintingData.fLatticeSelector[noiseX.noisePositionIntegerValue] + - noiseY.noisePositionIntegerValue; - int nextLatticeIndex = - paintingData.fLatticeSelector[(noiseX.noisePositionIntegerValue + 1) & kBlockMask] + - noiseY.noisePositionIntegerValue; + noiseX.nextNoisePositionIntegerValue &= kBlockMask; + noiseY.nextNoisePositionIntegerValue &= kBlockMask; + int i = + paintingData.fLatticeSelector[noiseX.noisePositionIntegerValue]; + int j = + paintingData.fLatticeSelector[noiseX.nextNoisePositionIntegerValue]; + int b00 = (i + noiseY.noisePositionIntegerValue) & kBlockMask; + int b10 = (j + noiseY.noisePositionIntegerValue) & kBlockMask; + int b01 = (i + noiseY.nextNoisePositionIntegerValue) & kBlockMask; + int b11 = (j + noiseY.nextNoisePositionIntegerValue) & kBlockMask; SkScalar sx = smoothCurve(noiseX.noisePositionFractionValue); SkScalar sy = smoothCurve(noiseY.noisePositionFractionValue); // This is taken 1:1 from SVG spec: http://www.w3.org/TR/SVG11/filters.html#feTurbulenceElement SkPoint fractionValue = SkPoint::Make(noiseX.noisePositionFractionValue, noiseY.noisePositionFractionValue); // Offset (0,0) - u = paintingData.fGradient[channel][latticeIndex & kBlockMask].dot(fractionValue); + u = paintingData.fGradient[channel][b00].dot(fractionValue); fractionValue.fX -= SK_Scalar1; // Offset (-1,0) - v = paintingData.fGradient[channel][nextLatticeIndex & kBlockMask].dot(fractionValue); + v = paintingData.fGradient[channel][b10].dot(fractionValue); SkScalar a = SkScalarInterp(u, v, sx); fractionValue.fY -= SK_Scalar1; // Offset (-1,-1) - v = paintingData.fGradient[channel][(nextLatticeIndex + 1) & kBlockMask].dot(fractionValue); + v = paintingData.fGradient[channel][b11].dot(fractionValue); fractionValue.fX = noiseX.noisePositionFractionValue; // Offset (0,-1) - u = paintingData.fGradient[channel][(latticeIndex + 1) & kBlockMask].dot(fractionValue); + u = paintingData.fGradient[channel][b01].dot(fractionValue); SkScalar b = SkScalarInterp(u, v, sx); return SkScalarInterp(a, b, sy); } @@ -989,13 +996,14 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, const char* chanCoord = "chanCoord"; const char* stitchData = "stitchData"; const char* ratio = "ratio"; - const char* noiseXY = "noiseXY"; const char* noiseVec = "noiseVec"; const char* noiseSmooth = "noiseSmooth"; + const char* floorVal = "floorVal"; const char* fractVal = "fractVal"; const char* uv = "uv"; const char* ab = "ab"; const char* latticeIdx = "latticeIdx"; + const char* bcoords = "bcoords"; const char* lattice = "lattice"; const char* inc8bit = "0.00390625"; // 1.0 / 256.0 // This is the math to convert the two 16bit integer packed into rgba 8 bit input into a @@ -1016,32 +1024,35 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, SkString noiseCode; - noiseCode.appendf("\tvec4 %s = vec4(floor(%s), fract(%s));", noiseXY, noiseVec, noiseVec); + noiseCode.appendf("\tvec4 %s;\n", floorVal); + noiseCode.appendf("\t%s.xy = floor(%s);\n", floorVal, noiseVec); + noiseCode.appendf("\t%s.zw = %s.xy + vec2(1.0);\n", floorVal, floorVal); + noiseCode.appendf("\tvec2 %s = fract(%s);\n", fractVal, noiseVec); // smooth curve : t * t * (3 - 2 * t) - noiseCode.appendf("\n\tvec2 %s = %s.zw * %s.zw * (vec2(3.0) - vec2(2.0) * %s.zw);", - noiseSmooth, noiseXY, noiseXY, noiseXY); + noiseCode.appendf("\n\tvec2 %s = %s * %s * (vec2(3.0) - vec2(2.0) * %s);", + noiseSmooth, fractVal, fractVal, fractVal); // Adjust frequencies if we're stitching tiles if (fStitchTiles) { noiseCode.appendf("\n\tif(%s.x >= %s.x) { %s.x -= %s.x; }", - noiseXY, stitchData, noiseXY, stitchData); - noiseCode.appendf("\n\tif(%s.x >= (%s.x - 1.0)) { %s.x -= (%s.x - 1.0); }", - noiseXY, stitchData, noiseXY, stitchData); + floorVal, stitchData, floorVal, stitchData); noiseCode.appendf("\n\tif(%s.y >= %s.y) { %s.y -= %s.y; }", - noiseXY, stitchData, noiseXY, stitchData); - noiseCode.appendf("\n\tif(%s.y >= (%s.y - 1.0)) { %s.y -= (%s.y - 1.0); }", - noiseXY, stitchData, noiseXY, stitchData); + floorVal, stitchData, floorVal, stitchData); + noiseCode.appendf("\n\tif(%s.z >= %s.x) { %s.z -= %s.x; }", + floorVal, stitchData, floorVal, stitchData); + noiseCode.appendf("\n\tif(%s.w >= %s.y) { %s.w -= %s.y; }", + floorVal, stitchData, floorVal, stitchData); } // Get texture coordinates and normalize - noiseCode.appendf("\n\t%s.xy = fract(floor(mod(%s.xy, 256.0)) / vec2(256.0));\n", - noiseXY, noiseXY); + noiseCode.appendf("\n\t%s = fract(floor(mod(%s, 256.0)) / vec4(256.0));\n", + floorVal, floorVal); // Get permutation for x { SkString xCoords(""); - xCoords.appendf("vec2(%s.x, 0.5)", noiseXY); + xCoords.appendf("vec2(%s.x, 0.5)", floorVal); noiseCode.appendf("\n\tvec2 %s;\n\t%s.x = ", latticeIdx, latticeIdx); builder->appendTextureLookup(&noiseCode, samplers[0], xCoords.c_str(), kVec2f_GrSLType); @@ -1051,7 +1062,7 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, // Get permutation for x + 1 { SkString xCoords(""); - xCoords.appendf("vec2(fract(%s.x + %s), 0.5)", noiseXY, inc8bit); + xCoords.appendf("vec2(%s.z, 0.5)", floorVal); noiseCode.appendf("\n\t%s.y = ", latticeIdx); builder->appendTextureLookup(&noiseCode, samplers[0], xCoords.c_str(), kVec2f_GrSLType); @@ -1070,15 +1081,13 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, #endif // Get (x,y) coordinates with the permutated x - noiseCode.appendf("\n\t%s = fract(%s + %s.yy);", latticeIdx, latticeIdx, noiseXY); - - noiseCode.appendf("\n\tvec2 %s = %s.zw;", fractVal, noiseXY); + noiseCode.appendf("\n\tvec4 %s = fract(%s.xyxy + %s.yyww);", bcoords, latticeIdx, floorVal); noiseCode.appendf("\n\n\tvec2 %s;", uv); // Compute u, at offset (0,0) { SkString latticeCoords(""); - latticeCoords.appendf("vec2(%s.x, %s)", latticeIdx, chanCoord); + latticeCoords.appendf("vec2(%s.x, %s)", bcoords, chanCoord); noiseCode.appendf("\n\tvec4 %s = ", lattice); builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(), kVec2f_GrSLType); @@ -1090,7 +1099,7 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, // Compute v, at offset (-1,0) { SkString latticeCoords(""); - latticeCoords.appendf("vec2(%s.y, %s)", latticeIdx, chanCoord); + latticeCoords.appendf("vec2(%s.y, %s)", bcoords, chanCoord); noiseCode.append("\n\tlattice = "); builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(), kVec2f_GrSLType); @@ -1106,7 +1115,7 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, // Compute v, at offset (-1,-1) { SkString latticeCoords(""); - latticeCoords.appendf("vec2(fract(%s.y + %s), %s)", latticeIdx, inc8bit, chanCoord); + latticeCoords.appendf("vec2(%s.w, %s)", bcoords, chanCoord); noiseCode.append("\n\tlattice = "); builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(), kVec2f_GrSLType); @@ -1118,7 +1127,7 @@ void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder, // Compute u, at offset (0,-1) { SkString latticeCoords(""); - latticeCoords.appendf("vec2(fract(%s.x + %s), %s)", latticeIdx, inc8bit, chanCoord); + latticeCoords.appendf("vec2(%s.z, %s)", bcoords, chanCoord); noiseCode.append("\n\tlattice = "); builder->appendTextureLookup(&noiseCode, samplers[1], latticeCoords.c_str(), kVec2f_GrSLType); -- 2.7.4