AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

SkBitmapProcState rounding bias

Browse Source 
Epsilon bias to keep bitmap sample rounding consistent with geometry
rounding.

Also update the GM to draw an outer border + drop uninteresting
scales in favor of negative scale variants.

BUG=skia:4680,skia:4649
R=reed@google.com,caryclark@google.com,mtklein@google.com

Review URL: https://codereview.chromium.org/1527633002
This commit is contained in:
fmalita 2015-12-15 06:48:48 -08:00 committed by Commit bot
parent 11f457e162
commit aed4d32de9
4 changed files with 45 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
gm/imagescalealigned.cpp
View File

@ -34,39 +34,29 @@ protected:
}
SkISize onISize() override {
return SkISize::Make(550, 300);
return SkISize::Make(580, 780);
}
void onDraw(SkCanvas* canvas) override {
struct {
SkPoint offset;
SkScalar scale;
SkVector scale;
} cfgs[] = {
{ { 10, 10 }, 1 },
{ { 140.5f, 10 }, 1 },
{ { 10, 80.5f }, 1 },
{ { 140.5f, 80.5f }, 1 },
{{ 10, 10 }, { 1, 1 }},
{{ 300.5f, 10 }, { 1, 1 }},
{{ 10, 200.5f }, { 1, 1 }},
{{ 300.5f, 200.5f }, { 1, 1 }},
{ { 280.49f, 10.49f }, 1 },
{ { 410.51f, 10.49f }, 1 },
{ { 280.49f, 80.51f }, 1 },
{ { 410.51f, 80.51f }, 1 },
{ { 10, 170 }, 1.1f },
{ { 140.5f, 170 }, 1.1f },
{ { 10, 240.5f }, 1.1f },
{ { 140.5f, 240.5f }, 1.1f },
{ { 280.49f, 170.49f }, 1.1f },
{ { 410.51f, 170.49f }, 1.1f },
{ { 280.49f, 240.51f }, 1.1f },
{ { 410.51f, 240.51f }, 1.1f },
{{ 10.5f, 400.5f }, { 1, 1 }},
{{ 550.5f, 400.5f }, { -1, 1 }},
{{ 10.5f, 750.5f }, { 1, -1 }},
{{ 550.5f, 750.5f }, { -1, -1 }},
};
for (size_t i = 0; i < SK_ARRAY_COUNT(cfgs); ++i) {
SkAutoCanvasRestore acr(canvas, true);
canvas->translate(cfgs[i].offset.x(), cfgs[i].offset.y());
canvas->scale(cfgs[i].scale, cfgs[i].scale);
canvas->scale(cfgs[i].scale.x(), cfgs[i].scale.y());
drawSets(canvas);
}
}
@ -88,6 +78,11 @@ private:
SkPaint paint;
paint.setAntiAlias(true);
const SkRect border = SkRect::MakeIWH(kSegLen, kSegLen).makeInset(.5f, .5f);
paint.setColor(SK_ColorBLUE);
paint.setStyle(SkPaint::kStroke_Style);
surface->getCanvas()->drawRect(border, paint);
paint.setColor(SK_ColorBLACK);
surface->getCanvas()->drawLine(start.x(), start.y(), end.x(), end.y(), paint);
surface->getCanvas()->drawPoint(start.x(), start.y(), color);
@ -116,12 +111,12 @@ private:
for (size_t k = 0; k < SK_ARRAY_COUNT(filters); ++k) {
paint.setFilterQuality(filters[k]);
lastPt = drawSet(canvas, set, paint);
canvas->translate((kSegLen / 2) * set.fVector.y(),
(kSegLen / 2) * set.fVector.x());
canvas->translate((kSegLen + 4) * set.fVector.y(),
(kSegLen + 4) * set.fVector.x());
}
}
canvas->translate(lastPt.x() + kSegLen,
- SkIntToScalar(kSegLen) / 2 * SK_ARRAY_COUNT(filters) * SK_ARRAY_COUNT(AAs));
- SkIntToScalar(kSegLen + 4) * SK_ARRAY_COUNT(filters) * SK_ARRAY_COUNT(AAs));
}
}
@ -143,8 +138,8 @@ private:
return pt;
}
static const unsigned kSegLen = 9;
static const unsigned kStretchFactor = 2;
static const unsigned kSegLen = 15;
static const unsigned kStretchFactor = 4;
SkSTArray<2, ImageSet> fSets;
typedef GM INHERITED;

6
src/core/SkBitmapProcState.cpp
View File

@ -823,10 +823,12 @@ void Clamp_S32_opaque_D32_nofilter_DX_shaderproc(const SkBitmapProcState& s, in
SkPoint pt;
s.fInvProc(s.fInvMatrix, SkIntToScalar(x) + SK_ScalarHalf, SkIntToScalar(y) + SK_ScalarHalf,
&pt);
fx = SkScalarToFractionalInt(pt.fY);
fx = SkScalarToFractionalInt(pt.fY)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleY());
const unsigned maxY = s.fPixmap.height() - 1;
dstY = SkClampMax(SkFractionalIntToInt(fx), maxY);
fx = SkScalarToFractionalInt(pt.fX);
fx = SkScalarToFractionalInt(pt.fX)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleX());
}
const SkPMColor* SK_RESTRICT src = s.fPixmap.addr32(0, dstY);

12
src/core/SkBitmapProcState.h
View File

@ -12,6 +12,7 @@
#include "SkBitmapController.h"
#include "SkBitmapFilter.h"
#include "SkBitmapProvider.h"
#include "SkFloatBits.h"
#include "SkMatrix.h"
#include "SkMipMap.h"
#include "SkPaint.h"
@ -24,6 +25,17 @@ typedef SkFixed3232 SkFractionalInt;
#define SkFixedToFractionalInt(x) SkFixedToFixed3232(x)
#define SkFractionalIntToInt(x) SkFixed3232ToInt(x)
// Applying a fixed point (SkFixed, SkFractionalInt) epsilon bias ensures that the inverse-mapped
// bitmap coordinates are rounded consistently WRT geometry. Note that we only have to do this
// when the scale is positive - for negative scales we're already rounding in the right direction.
static inline int bitmap_sampler_inv_bias(SkScalar scale) {
#ifndef SK_SUPPORT_LEGACY_BITMAP_SAMPLER_BIAS
return -(scale > 0);
#else
return 0;
#endif
}
class SkPaint;
struct SkBitmapProcState {

12
src/core/SkBitmapProcState_matrix.h
View File

@ -64,12 +64,14 @@ void SCALE_FILTER_NAME(const SkBitmapProcState& s,
SkPoint pt;
s.fInvProc(s.fInvMatrix, SkIntToScalar(x) + SK_ScalarHalf,
SkIntToScalar(y) + SK_ScalarHalf, &pt);
const SkFixed fy = SkScalarToFixed(pt.fY) - (s.fFilterOneY >> 1);
const SkFixed fy = SkScalarToFixed(pt.fY) - (s.fFilterOneY >> 1)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleY());
const unsigned maxY = s.fPixmap.height() - 1;
// compute our two Y values up front
*xy++ = PACK_FILTER_Y_NAME(fy, maxY, s.fFilterOneY PREAMBLE_ARG_Y);
// now initialize fx
fx = SkScalarToFractionalInt(pt.fX) - (SkFixedToFractionalInt(one) >> 1);
fx = SkScalarToFractionalInt(pt.fX) - (SkFixedToFractionalInt(one) >> 1)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleX());
}
#ifdef CHECK_FOR_DECAL
@ -102,8 +104,10 @@ void AFFINE_FILTER_NAME(const SkBitmapProcState& s,
SkFixed oneX = s.fFilterOneX;
SkFixed oneY = s.fFilterOneY;
SkFixed fx = SkScalarToFixed(srcPt.fX) - (oneX >> 1);
SkFixed fy = SkScalarToFixed(srcPt.fY) - (oneY >> 1);
SkFixed fx = SkScalarToFixed(srcPt.fX) - (oneX >> 1)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleX());
SkFixed fy = SkScalarToFixed(srcPt.fY) - (oneY >> 1)
+ bitmap_sampler_inv_bias(s.fInvMatrix.getScaleY());
SkFixed dx = s.fInvSx;
SkFixed dy = s.fInvKy;
unsigned maxX = s.fPixmap.width() - 1;