fix fiddle with blur
Docs-Preview: https://skia.org/?cl=114018
NOTRY=true
R=caryclark@google.com
Bug: skia:6898
Change-Id: Ied96a0b8479a9b359299ba24ecfa55022046beb0
Reviewed-on: https://skia-review.googlesource.com/114018
Commit-Queue: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
diff --git a/docs/SkBitmap_Reference.bmh b/docs/SkBitmap_Reference.bmh
index 353d244..78b527a 100644
--- a/docs/SkBitmap_Reference.bmh
+++ b/docs/SkBitmap_Reference.bmh
@@ -640,16 +640,16 @@
bitmap.bytesPerPixel());
}
#StdOut
-color: kUnknown_SkColorType bytesPerPixel: 0
-color: kAlpha_8_SkColorType bytesPerPixel: 1
-color: kRGB_565_SkColorType bytesPerPixel: 2
-color: kARGB_4444_SkColorType bytesPerPixel: 2
-color: kRGBA_8888_SkColorType bytesPerPixel: 4
-color: kRGB_888x_SkColorType bytesPerPixel: 4
-color: kBGRA_8888_SkColorType bytesPerPixel: 4
-color: kRGBA_1010102_SkColorType bytesPerPixel: 4
-color: kRGB_101010x_SkColorType bytesPerPixel: 4
-color: kGray_8_SkColorType bytesPerPixel: 1
+color: kUnknown_SkColorType bytesPerPixel: 0
+color: kAlpha_8_SkColorType bytesPerPixel: 1
+color: kRGB_565_SkColorType bytesPerPixel: 2
+color: kARGB_4444_SkColorType bytesPerPixel: 2
+color: kRGBA_8888_SkColorType bytesPerPixel: 4
+color: kRGB_888x_SkColorType bytesPerPixel: 4
+color: kBGRA_8888_SkColorType bytesPerPixel: 4
+color: kRGBA_1010102_SkColorType bytesPerPixel: 4
+color: kRGB_101010x_SkColorType bytesPerPixel: 4
+color: kGray_8_SkColorType bytesPerPixel: 1
color: kRGBA_F16_SkColorType bytesPerPixel: 8
##
##
@@ -710,16 +710,16 @@
bitmap.shiftPerPixel());
}
#StdOut
-color: kUnknown_SkColorType shiftPerPixel: 0
-color: kAlpha_8_SkColorType shiftPerPixel: 0
-color: kRGB_565_SkColorType shiftPerPixel: 1
-color: kARGB_4444_SkColorType shiftPerPixel: 1
-color: kRGBA_8888_SkColorType shiftPerPixel: 2
-color: kRGB_888x_SkColorType shiftPerPixel: 2
-color: kBGRA_8888_SkColorType shiftPerPixel: 2
-color: kRGBA_1010102_SkColorType shiftPerPixel: 2
-color: kRGB_101010x_SkColorType shiftPerPixel: 2
-color: kGray_8_SkColorType shiftPerPixel: 0
+color: kUnknown_SkColorType shiftPerPixel: 0
+color: kAlpha_8_SkColorType shiftPerPixel: 0
+color: kRGB_565_SkColorType shiftPerPixel: 1
+color: kARGB_4444_SkColorType shiftPerPixel: 1
+color: kRGBA_8888_SkColorType shiftPerPixel: 2
+color: kRGB_888x_SkColorType shiftPerPixel: 2
+color: kBGRA_8888_SkColorType shiftPerPixel: 2
+color: kRGBA_1010102_SkColorType shiftPerPixel: 2
+color: kRGB_101010x_SkColorType shiftPerPixel: 2
+color: kGray_8_SkColorType shiftPerPixel: 0
color: kRGBA_F16_SkColorType shiftPerPixel: 3
##
##
@@ -3287,25 +3287,28 @@
#Bug 7103
#Example
#Height 160
- SkBitmap alpha, bitmap;
- bitmap.allocN32Pixels(100, 100);
- SkCanvas offscreen(bitmap);
- offscreen.clear(0);
- SkPaint paint;
- paint.setAntiAlias(true);
- paint.setColor(SK_ColorBLUE);
- paint.setStyle(SkPaint::kStroke_Style);
- paint.setStrokeWidth(20);
- offscreen.drawCircle(50, 50, 39, paint);
- offscreen.flush();
- const SkScalar kBlurSigma = SkBlurMaskFilter::ConvertRadiusToSigma(SkIntToScalar(25));
- paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, kBlurSigma,
- SkBlurMaskFilter::kHighQuality_BlurFlag));
- SkIPoint offset;
- bitmap.extractAlpha(&alpha, &paint, &offset);
- paint.setColor(SK_ColorRED);
- canvas->drawBitmap(bitmap, 0, -offset.fY, &paint);
- canvas->drawBitmap(alpha, 100 + offset.fX, 0, &paint);
+ auto radiusToSigma = [](SkScalar radius) -> SkScalar {
+ static const SkScalar kBLUR_SIGMA_SCALE = 0.57735f;
+ return radius > 0 ? kBLUR_SIGMA_SCALE * radius + 0.5f : 0.0f;
+ };
+ SkBitmap alpha, bitmap;
+ bitmap.allocN32Pixels(100, 100);
+ SkCanvas offscreen(bitmap);
+ offscreen.clear(0);
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setColor(SK_ColorBLUE);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(20);
+ offscreen.drawCircle(50, 50, 39, paint);
+ offscreen.flush();
+ paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, radiusToSigma(25),
+ SkBlurMaskFilter::kHighQuality_BlurFlag));
+ SkIPoint offset;
+ bitmap.extractAlpha(&alpha, &paint, &offset);
+ paint.setColor(SK_ColorRED);
+ canvas->drawBitmap(bitmap, 0, -offset.fY, &paint);
+ canvas->drawBitmap(alpha, 100 + offset.fX, 0, &paint);
##
#SeeAlso extractSubset
diff --git a/site/user/api/SkBitmap_Reference.md b/site/user/api/SkBitmap_Reference.md
index 437b4cc..999460c 100644
--- a/site/user/api/SkBitmap_Reference.md
+++ b/site/user/api/SkBitmap_Reference.md
@@ -3518,7 +3518,7 @@
### Example
-<div><fiddle-embed name="e122936b119f20098aace454c2105a12"></fiddle-embed></div>
+<div><fiddle-embed name="c102065eea5c3f109fdcad3f0e269ce5"></fiddle-embed></div>
### See Also
diff --git a/site/user/api/catalog.htm b/site/user/api/catalog.htm
index 868f0fa..261f7d8 100644
--- a/site/user/api/catalog.htm
+++ b/site/user/api/catalog.htm
@@ -3766,10 +3766,10 @@
"name": "SkBitmap::extractAlpha"
},
"SkBitmap_extractAlpha_2": {
- "code": "void draw(SkCanvas* canvas) {\n SkBitmap alpha, bitmap;\n bitmap.allocN32Pixels(100, 100);\n SkCanvas offscreen(bitmap);\n offscreen.clear(0);\n SkPaint paint;\n paint.setAntiAlias(true);\n paint.setColor(SK_ColorBLUE);\n paint.setStyle(SkPaint::kStroke_Style);\n paint.setStrokeWidth(20);\n offscreen.drawCircle(50, 50, 39, paint);\n offscreen.flush();\n const SkScalar kBlurSigma = SkBlurMaskFilter::ConvertRadiusToSigma(SkIntToScalar(25));\n paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, kBlurSigma,\n SkBlurMaskFilter::kHighQuality_BlurFlag));\n SkIPoint offset;\n bitmap.extractAlpha(&alpha, &paint, &offset);\n paint.setColor(SK_ColorRED);\n canvas->drawBitmap(bitmap, 0, -offset.fY, &paint);\n canvas->drawBitmap(alpha, 100 + offset.fX, 0, &paint);\n}",
+ "code": "void draw(SkCanvas* canvas) {\n auto radiusToSigma = [](SkScalar radius) -> SkScalar {\n static const SkScalar kBLUR_SIGMA_SCALE = 0.57735f;\n return radius > 0 ? kBLUR_SIGMA_SCALE * radius + 0.5f : 0.0f;\n };\n SkBitmap alpha, bitmap;\n bitmap.allocN32Pixels(100, 100);\n SkCanvas offscreen(bitmap);\n offscreen.clear(0);\n SkPaint paint;\n paint.setAntiAlias(true);\n paint.setColor(SK_ColorBLUE);\n paint.setStyle(SkPaint::kStroke_Style);\n paint.setStrokeWidth(20);\n offscreen.drawCircle(50, 50, 39, paint);\n offscreen.flush();\n paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, radiusToSigma(25),\n SkBlurMaskFilter::kHighQuality_BlurFlag));\n SkIPoint offset;\n bitmap.extractAlpha(&alpha, &paint, &offset);\n paint.setColor(SK_ColorRED);\n canvas->drawBitmap(bitmap, 0, -offset.fY, &paint);\n canvas->drawBitmap(alpha, 100 + offset.fX, 0, &paint);\n}",
"width": 256,
"height": 160,
- "hash": "e122936b119f20098aace454c2105a12",
+ "hash": "c102065eea5c3f109fdcad3f0e269ce5",
"file": "SkBitmap_Reference",
"name": "SkBitmap::extractAlpha_2"
},