Add test to exercise extreme blur sigmas
https://codereview.chromium.org/23530039/
git-svn-id: http://skia.googlecode.com/svn/trunk@11099 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/BlurTest.cpp b/tests/BlurTest.cpp
index 6fb36b6..5cd1cca 100644
--- a/tests/BlurTest.cpp
+++ b/tests/BlurTest.cpp
@@ -6,10 +6,17 @@
* found in the LICENSE file.
*/
#include "Test.h"
+#include "SkBlurMask.h"
#include "SkBlurMaskFilter.h"
#include "SkCanvas.h"
#include "SkMath.h"
#include "SkPaint.h"
+#if SK_SUPPORT_GPU
+#include "GrContextFactory.h"
+#include "SkGpuDevice.h"
+#endif
+
+#define WRITE_CSV 0
///////////////////////////////////////////////////////////////////////////////
@@ -88,7 +95,7 @@
return true;
}
-static void test_blur(skiatest::Reporter* reporter) {
+static void test_blur_drawing(skiatest::Reporter* reporter) {
SkPaint paint;
paint.setColor(SK_ColorGRAY);
@@ -145,5 +152,236 @@
}
}
+///////////////////////////////////////////////////////////////////////////////
+
+// Use SkBlurMask::BlurGroundTruth to blur a 'width' x 'height' solid
+// white rect. Return the right half of the middle row in 'result'.
+static void ground_truth_2d(int width, int height,
+ SkScalar sigma,
+ int* result, int resultCount) {
+ SkMask src, dst;
+
+ src.fBounds.set(0, 0, width, height);
+ src.fFormat = SkMask::kA8_Format;
+ src.fRowBytes = src.fBounds.width();
+ src.fImage = SkMask::AllocImage(src.computeTotalImageSize());
+
+ memset(src.fImage, 0xff, src.computeTotalImageSize());
+
+ dst.fImage = NULL;
+ SkBlurMask::BlurGroundTruth(sigma, &dst, src, SkBlurMask::kNormal_Style);
+
+ int midX = dst.fBounds.centerX();
+ int midY = dst.fBounds.centerY();
+ uint8_t* bytes = dst.getAddr8(midX, midY);
+ int i;
+ for (i = 0; i < dst.fBounds.width()-(midX-dst.fBounds.fLeft); ++i) {
+ if (i < resultCount) {
+ result[i] = bytes[i];
+ }
+ }
+ for ( ; i < resultCount; ++i) {
+ result[i] = 0;
+ }
+}
+
+// Implement a step function that is 255 between min and max; 0 elsewhere.
+static int step(int x, SkScalar min, SkScalar max) {
+ if (min < x && x < max) {
+ return 255;
+ }
+ return 0;
+}
+
+// Implement a Gaussian function with 0 mean and std.dev. of 'sigma'.
+static float gaussian(int x, SkScalar sigma) {
+ float k = SK_Scalar1/(sigma * sqrt(2.0f*SK_ScalarPI));
+ float exponent = -(x * x) / (2 * sigma * sigma);
+ return k * exp(exponent);
+}
+
+// Perform a brute force convolution of a step function with a Gaussian.
+// Return the right half in 'result'
+static void brute_force_1d(SkScalar stepMin, SkScalar stepMax,
+ SkScalar gaussianSigma,
+ int* result, int resultCount) {
+
+ int gaussianRange = SkScalarCeilToInt(10 * gaussianSigma);
+
+ for (int i = 0; i < resultCount; ++i) {
+ SkScalar sum = 0.0f;
+ for (int j = -gaussianRange; j < gaussianRange; ++j) {
+ sum += gaussian(j, gaussianSigma) * step(i-j, stepMin, stepMax);
+ }
+
+ result[i] = SkClampMax(SkClampPos(int(sum + 0.5f)), 255);
+ }
+}
+
+static void blur_path(SkCanvas* canvas, const SkPath& path,
+ SkScalar gaussianSigma) {
+
+ SkScalar midX = path.getBounds().centerX();
+ SkScalar midY = path.getBounds().centerY();
+
+ canvas->translate(-midX, -midY);
+
+ SkPaint blurPaint;
+ blurPaint.setColor(SK_ColorWHITE);
+ SkMaskFilter* filter = SkBlurMaskFilter::Create(SkBlurMaskFilter::kNormal_BlurStyle,
+ gaussianSigma,
+ SkBlurMaskFilter::kHighQuality_BlurFlag);
+ blurPaint.setMaskFilter(filter)->unref();
+
+ canvas->drawColor(SK_ColorBLACK);
+ canvas->drawPath(path, blurPaint);
+}
+
+// Readback the blurred draw results from the canvas
+static void readback(SkCanvas* canvas, int* result, int resultCount) {
+ SkBitmap readback;
+ readback.setConfig(SkBitmap::kARGB_8888_Config, resultCount, 30);
+ readback.allocPixels();
+
+ SkIRect readBackRect = { 0, 0, resultCount, 30 };
+
+ canvas->readPixels(readBackRect, &readback);
+
+ readback.lockPixels();
+ SkPMColor* pixels = (SkPMColor*) readback.getAddr32(0, 15);
+
+ for (int i = 0; i < resultCount; ++i) {
+ result[i] = SkColorGetR(pixels[i]);
+ }
+}
+
+// Draw a blurred version of the provided path.
+// Return the right half of the middle row in 'result'.
+static void cpu_blur_path(const SkPath& path, SkScalar gaussianSigma,
+ int* result, int resultCount) {
+
+ SkBitmap bitmap;
+ bitmap.setConfig(SkBitmap::kARGB_8888_Config, resultCount, 30);
+ bitmap.allocPixels();
+ SkCanvas canvas(bitmap);
+
+ blur_path(&canvas, path, gaussianSigma);
+ readback(&canvas, result, resultCount);
+}
+
+#if SK_SUPPORT_GPU
+static void gpu_blur_path(GrContextFactory* factory, const SkPath& path,
+ SkScalar gaussianSigma,
+ int* result, int resultCount) {
+
+ GrContext* grContext = factory->get(GrContextFactory::kNative_GLContextType);
+ if (NULL == grContext) {
+ return;
+ }
+
+ GrTextureDesc desc;
+ desc.fConfig = kSkia8888_GrPixelConfig;
+ desc.fFlags = kRenderTarget_GrTextureFlagBit;
+ desc.fWidth = resultCount;
+ desc.fHeight = 30;
+ desc.fSampleCnt = 0;
+
+ SkAutoTUnref<GrTexture> texture(grContext->createUncachedTexture(desc, NULL, 0));
+ SkAutoTUnref<SkGpuDevice> device(SkNEW_ARGS(SkGpuDevice, (grContext, texture.get())));
+ SkCanvas canvas(device.get());
+
+ blur_path(&canvas, path, gaussianSigma);
+ readback(&canvas, result, resultCount);
+}
+#endif
+
+#if WRITE_CSV
+static void write_as_csv(const char* label, SkScalar scale, int* data, int count) {
+ SkDebugf("%s_%.2f,", label, scale);
+ for (int i = 0; i < count-1; ++i) {
+ SkDebugf("%d,", data[i]);
+ }
+ SkDebugf("%d\n", data[count-1]);
+}
+#endif
+
+static bool match(int* first, int* second, int count, int tol) {
+ int delta;
+ for (int i = 0; i < count; ++i) {
+ delta = first[i] - second[i];
+ if (delta > tol || delta < -tol) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+// Test out the normal blur style with a wide range of sigmas
+static void test_sigma_range(skiatest::Reporter* reporter, GrContextFactory* factory) {
+
+ static const int kSize = 100;
+
+ // The geometry is offset a smidge to trigger:
+ // https://code.google.com/p/chromium/issues/detail?id=282418
+ SkPath rectPath;
+ rectPath.addRect(0.3f, 0.3f, 100.3f, 100.3f);
+
+ SkPoint polyPts[] = {
+ { 0.3f, 0.3f },
+ { 100.3f, 0.3f },
+ { 100.3f, 100.3f },
+ { 0.3f, 100.3f },
+ { 2.3f, 50.3f } // a little divet to throw off the rect special case
+ };
+ SkPath polyPath;
+ polyPath.addPoly(polyPts, SK_ARRAY_COUNT(polyPts), true);
+
+ int rectSpecialCaseResult[kSize];
+ int generalCaseResult[kSize];
+#if SK_SUPPORT_GPU
+ int gpuResult[kSize];
+#endif
+ int groundTruthResult[kSize];
+ int bruteForce1DResult[kSize];
+
+ SkScalar sigma = SkFloatToScalar(10.0f);
+
+ for (int i = 0; i < 4; ++i, sigma /= 10) {
+
+ cpu_blur_path(rectPath, sigma, rectSpecialCaseResult, kSize);
+ cpu_blur_path(polyPath, sigma, generalCaseResult, kSize);
+#if SK_SUPPORT_GPU
+ gpu_blur_path(factory, rectPath, sigma, gpuResult, kSize);
+#endif
+ ground_truth_2d(100, 100, sigma, groundTruthResult, kSize);
+ brute_force_1d(-50.0f, 50.0f, sigma, bruteForce1DResult, kSize);
+
+ REPORTER_ASSERT(reporter, match(rectSpecialCaseResult, bruteForce1DResult, kSize, 5));
+ REPORTER_ASSERT(reporter, match(generalCaseResult, bruteForce1DResult, kSize, 15));
+#if SK_SUPPORT_GPU
+ REPORTER_ASSERT(reporter, match(gpuResult, bruteForce1DResult, kSize, 1));
+#endif
+ REPORTER_ASSERT(reporter, match(groundTruthResult, bruteForce1DResult, kSize, 1));
+
+#if WRITE_CSV
+ write_as_csv("RectSpecialCase", sigma, rectSpecialCaseResult, kSize);
+ write_as_csv("GeneralCase", sigma, generalCaseResult, kSize);
+#if SK_SUPPORT_GPU
+ write_as_csv("GPU", sigma, gpuResult, kSize);
+#endif
+ write_as_csv("GroundTruth2D", sigma, groundTruthResult, kSize);
+ write_as_csv("BruteForce1D", sigma, bruteForce1DResult, kSize);
+#endif
+ }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+static void test_blur(skiatest::Reporter* reporter, GrContextFactory* factory) {
+ test_blur_drawing(reporter);
+ test_sigma_range(reporter, factory);
+}
+
#include "TestClassDef.h"
-DEFINE_TESTCLASS("BlurMaskFilter", BlurTestClass, test_blur)
+DEFINE_GPUTESTCLASS("BlurMaskFilter", BlurTestClass, test_blur)