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
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 @@
# 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 @@
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 @@
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 @@
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 @@
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 @@
if (noiseValue >= limitValue) {
noiseValue -= newValue;
}
- if (noiseValue >= limitValue - 1) {
- noiseValue -= newValue - 1;
- }
return noiseValue;
}
@@ -320,12 +317,14 @@
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 @@
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 @@
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 @@
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 @@
// 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 @@
#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 @@
// 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 @@
// 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 @@
// 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);
