Distance field fixes for Android

- Expand glyph size by 2 on each side to compensate for bilerp lookup
- Correct for Adreno tendency to drop entire tile if any pixel has divide-by-0
- Fix blurriness on Adreno by using uv coords to compute gradient instead
  of st coords
- Add faster version for uniform scale

BUG=skia:2173
R=bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/205343008

git-svn-id: http://skia.googlecode.com/svn/trunk@13955 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
commit-bot@chromium.org 2014-03-26 18:03:05 +00:00
parent 3fcab54c7f
commit 8fe2ee1cf3
11 changed files with 87 additions and 48 deletions

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@ -336,10 +336,10 @@ bool SkGenerateDistanceFieldFromImage(unsigned char* distanceField,
SkASSERT(NULL != image);
// the final distance field will have additional texels on each side to handle
// the maximum distance
// the maximum distance + 1 for bilerp
// we expand our temp data by one more on each side to simplify
// the scanning code -- will always be treated as infinitely far away
int pad = distanceMagnitude+1;
int pad = distanceMagnitude+2;
// set params for distance field data
int dataWidth = width + 2*pad;

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@ -209,7 +209,3 @@ GrPlot* GrAtlasMgr::getUnusedPlot() {
return NULL;
}
SkISize GrAtlas::getSize() const {
return SkISize::Make(GR_ATLAS_TEXTURE_WIDTH, GR_ATLAS_TEXTURE_HEIGHT);
}

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@ -103,8 +103,6 @@ public:
bool isEmpty() { return 0 == fPlots.count(); }
SkISize getSize() const;
private:
SkTDArray<GrPlot*> fPlots;

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@ -81,10 +81,10 @@ void GrDistanceFieldTextContext::flushGlyphs() {
GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kBilerp_FilterMode);
// This effect could be stored with one of the cache objects (atlas?)
SkISize size = fStrike->getAtlasSize();
drawState->addCoverageEffect(
GrDistanceFieldTextureEffect::Create(fCurrTexture, params, size),
kGlyphCoordsAttributeIndex)->unref();
GrDistanceFieldTextureEffect::Create(fCurrTexture, params,
fContext->getMatrix().isSimilarity()),
kGlyphCoordsAttributeIndex)->unref();
if (!GrPixelConfigIsAlphaOnly(fCurrTexture->config())) {
if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||

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@ -232,8 +232,9 @@ public:
builder->fsCodeAppend("\tfloat grad_dot = dot(grad, grad);\n");
// we need to clamp the length^2 of the gradiant vector to a non-zero value, because
// on the Nexus 4 the undefined result of inversesqrt(0) drops out an entire tile
// TODO: restrict this to Adreno-only
builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) {
builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
}
builder->fsCodeAppend("\tfloat invlen = inversesqrt(grad_dot);\n");
builder->fsCodeAppend("\tfloat edgeAlpha = clamp(0.5-test*invlen, 0.0, 1.0);\n");
@ -380,8 +381,9 @@ public:
builder->fsCodeAppend("\tfloat grad_dot = dot(grad, grad);\n");
// we need to clamp the length^2 of the gradiant vector to a non-zero value, because
// on the Nexus 4 the undefined result of inversesqrt(0) drops out an entire tile
// TODO: restrict this to Adreno-only
builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) {
builder->fsCodeAppend("\tgrad_dot = max(grad_dot, 1.0e-4);\n");
}
builder->fsCodeAppend("\tfloat invlen = inversesqrt(grad_dot);\n");
if (kHairline == ellipseEffect.getMode()) {
// can probably do this with one step

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@ -181,7 +181,11 @@ void GrFontCache::dump() const {
GrTexture* texture = fAtlasMgr[i]->getTexture();
if (NULL != texture) {
SkString filename;
#ifdef SK_BUILD_FOR_ANDROID
filename.printf("/sdcard/fontcache_%d%d.png", gDumpCount, i);
#else
filename.printf("fontcache_%d%d.png", gDumpCount, i);
#endif
texture->savePixels(filename.c_str());
}
}
@ -248,11 +252,13 @@ GrGlyph* GrTextStrike::generateGlyph(GrGlyph::PackedID packed,
GrGlyph* glyph = fPool.alloc();
// expand bounds to hold full distance field data
// + room for bilerp
int pad = DISTANCE_FIELD_RANGE+1;
if (fUseDistanceField) {
bounds.fLeft -= DISTANCE_FIELD_RANGE;
bounds.fRight += DISTANCE_FIELD_RANGE;
bounds.fTop -= DISTANCE_FIELD_RANGE;
bounds.fBottom += DISTANCE_FIELD_RANGE;
bounds.fLeft -= pad;
bounds.fRight += pad;
bounds.fTop -= pad;
bounds.fBottom += pad;
}
glyph->init(packed, bounds);
fCache.insert(packed, glyph);
@ -292,8 +298,9 @@ bool GrTextStrike::addGlyphToAtlas(GrGlyph* glyph, GrFontScaler* scaler) {
// but must shrink back down to get the packed glyph data
int dfWidth = glyph->width();
int dfHeight = glyph->height();
int width = dfWidth - 2*DISTANCE_FIELD_RANGE;
int height = dfHeight - 2*DISTANCE_FIELD_RANGE;
int pad = DISTANCE_FIELD_RANGE+1;
int width = dfWidth - 2*pad;
int height = dfHeight - 2*pad;
int stride = width*bytesPerPixel;
size_t size = width * height * bytesPerPixel;

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@ -39,8 +39,6 @@ public:
inline GrGlyph* getGlyph(GrGlyph::PackedID, GrFontScaler*);
bool addGlyphToAtlas(GrGlyph*, GrFontScaler*);
SkISize getAtlasSize() const { return fAtlas.getSize(); }
// testing
int countGlyphs() const { return fCache.getArray().count(); }
const GrGlyph* glyphAt(int index) const {

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@ -35,6 +35,8 @@ public:
SkASSERT(1 == drawEffect.castEffect<GrDistanceFieldTextureEffect>().numVertexAttribs());
SkAssertResult(builder->enableFeature(GrGLShaderBuilder::kStandardDerivatives_GLSLFeature));
const GrDistanceFieldTextureEffect& dfTexEffect =
drawEffect.castEffect<GrDistanceFieldTextureEffect>();
SkString fsCoordName;
const char* vsCoordName;
@ -61,16 +63,37 @@ public:
// we adjust for the effect of the transformation on the distance by using
// the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
builder->fsCodeAppendf("\tvec2 st = %s*%s;\n", fsCoordName.c_str(), textureSizeUniName);
builder->fsCodeAppend("\tvec2 Jdx = dFdx(st);\n");
builder->fsCodeAppend("\tvec2 Jdy = dFdy(st);\n");
builder->fsCodeAppend("\tvec2 st_grad = normalize(st);\n");
builder->fsCodeAppend("\tvec2 grad = vec2(st_grad.x*Jdx.x + st_grad.y*Jdy.x,\n");
builder->fsCodeAppend("\t st_grad.x*Jdx.y + st_grad.y*Jdy.y);\n");
builder->fsCodeAppendf("\tvec2 uv = %s;\n", fsCoordName.c_str());
builder->fsCodeAppendf("\tvec2 st = uv*%s;\n", textureSizeUniName);
builder->fsCodeAppend("\tfloat afwidth;\n");
if (dfTexEffect.isUniformScale()) {
// this gives us a smooth step across approximately one fragment
// (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2)
builder->fsCodeAppend("\tafwidth = 0.7071*dFdx(st.x);\n");
} else {
builder->fsCodeAppend("\tvec2 Jdx = dFdx(st);\n");
builder->fsCodeAppend("\tvec2 Jdy = dFdy(st);\n");
builder->fsCodeAppend("\tvec2 uv_grad;\n");
if (builder->ctxInfo().caps()->dropsTileOnZeroDivide()) {
// this is to compensate for the Adreno, which likes to drop tiles on division by 0
builder->fsCodeAppend("\tfloat uv_len2 = dot(uv, uv);\n");
builder->fsCodeAppend("\tif (uv_len2 < 0.0001) {\n");
builder->fsCodeAppend("\t\tuv_grad = vec2(0.7071, 0.7071);\n");
builder->fsCodeAppend("\t} else {\n");
builder->fsCodeAppend("\t\tuv_grad = uv*inversesqrt(uv_len2);\n");
builder->fsCodeAppend("\t}\n");
} else {
builder->fsCodeAppend("\tuv_grad = normalize(uv);\n");
}
builder->fsCodeAppend("\tvec2 grad = vec2(uv_grad.x*Jdx.x + uv_grad.y*Jdy.x,\n");
builder->fsCodeAppend("\t uv_grad.x*Jdx.y + uv_grad.y*Jdy.y);\n");
// this gives us a smooth step across approximately one fragment
// (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2)
builder->fsCodeAppend("\tafwidth = 0.7071*length(grad);\n");
}
// this gives us a smooth step across approximately one fragment
// (assuming a radius of the diagonal of the fragment, hence a factor of sqrt(2)/2)
builder->fsCodeAppend("\tfloat afwidth = 0.7071*length(grad);\n");
builder->fsCodeAppend("\tfloat val = smoothstep(-afwidth, afwidth, distance);\n");
builder->fsCodeAppendf("\t%s = %s;\n", outputColor,
@ -80,17 +103,24 @@ public:
virtual void setData(const GrGLUniformManager& uman,
const GrDrawEffect& drawEffect) SK_OVERRIDE {
SkASSERT(fTextureSizeUni.isValid());
const GrDistanceFieldTextureEffect& distanceFieldEffect =
drawEffect.castEffect<GrDistanceFieldTextureEffect>();
if (distanceFieldEffect.getSize().width() != fTextureSize.width() ||
distanceFieldEffect.getSize().height() != fTextureSize.height()) {
fTextureSize = distanceFieldEffect.getSize();
GrTexture* texture = drawEffect.effect()->get()->texture(0);
if (texture->width() != fTextureSize.width() ||
texture->height() != fTextureSize.height()) {
fTextureSize = SkSize::Make(texture->width(), texture->height());
uman.set2f(fTextureSizeUni,
distanceFieldEffect.getSize().width(),
distanceFieldEffect.getSize().height());
fTextureSize.width(),
fTextureSize.height());
}
}
static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
const GrDistanceFieldTextureEffect& dfTexEffect =
drawEffect.castEffect<GrDistanceFieldTextureEffect>();
return dfTexEffect.isUniformScale() ? 0x1 : 0x0;
}
private:
GrGLUniformManager::UniformHandle fTextureSizeUni;
SkSize fTextureSize;
@ -102,9 +132,9 @@ private:
GrDistanceFieldTextureEffect::GrDistanceFieldTextureEffect(GrTexture* texture,
const GrTextureParams& params,
const SkISize& size)
bool uniformScale)
: fTextureAccess(texture, params)
, fSize(SkSize::Make(SkIntToScalar(size.width()), SkIntToScalar(size.height()))) {
, fUniformScale(uniformScale) {
this->addTextureAccess(&fTextureAccess);
this->addVertexAttrib(kVec2f_GrSLType);
}
@ -149,7 +179,6 @@ GrEffectRef* GrDistanceFieldTextureEffect::TestCreate(SkRandom* random,
};
GrTextureParams params(tileModes, random->nextBool() ? GrTextureParams::kBilerp_FilterMode :
GrTextureParams::kNone_FilterMode);
SkISize size = SkISize::Make(1024, 2048);
return GrDistanceFieldTextureEffect::Create(textures[texIdx], params, size);
return GrDistanceFieldTextureEffect::Create(textures[texIdx], params, random->nextBool());
}

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@ -21,8 +21,8 @@ class GrGLDistanceFieldTextureEffect;
*/
class GrDistanceFieldTextureEffect : public GrVertexEffect {
public:
static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& p, const SkISize& s) {
AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, p, s)));
static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& para, bool uniformScale) {
AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, para, uniformScale)));
return CreateEffectRef(effect);
}
@ -31,7 +31,7 @@ public:
static const char* Name() { return "DistanceFieldTexture"; }
virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
const SkSize& getSize() const { return fSize; }
bool isUniformScale() const { return fUniformScale; }
typedef GrGLDistanceFieldTextureEffect GLEffect;
@ -39,12 +39,12 @@ public:
private:
GrDistanceFieldTextureEffect(GrTexture* texture, const GrTextureParams& params,
const SkISize& textureSize);
bool uniformScale);
virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
GrTextureAccess fTextureAccess;
SkSize fSize;
bool fUniformScale;
GR_DECLARE_EFFECT_TEST;

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@ -47,6 +47,7 @@ void GrGLCaps::reset() {
fFixedFunctionSupport = false;
fDiscardFBSupport = false;
fFullClearIsFree = false;
fDropsTileOnZeroDivide = false;
}
GrGLCaps::GrGLCaps(const GrGLCaps& caps) : GrDrawTargetCaps() {
@ -84,6 +85,7 @@ GrGLCaps& GrGLCaps::operator = (const GrGLCaps& caps) {
fFixedFunctionSupport = caps.fFixedFunctionSupport;
fDiscardFBSupport = caps.fDiscardFBSupport;
fFullClearIsFree = caps.fFullClearIsFree;
fDropsTileOnZeroDivide = caps.fDropsTileOnZeroDivide;
return *this;
}
@ -244,6 +246,9 @@ void GrGLCaps::init(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
}
}
// Adreno GPUs have a tendency to drop tiles when there is a divide-by-zero in a shader
fDropsTileOnZeroDivide = kQualcomm_GrGLVendor == ctxInfo.vendor();
this->initFSAASupport(ctxInfo, gli);
this->initStencilFormats(ctxInfo);
@ -661,5 +666,6 @@ SkString GrGLCaps::dump() const {
(fUseNonVBOVertexAndIndexDynamicData ? "YES" : "NO"));
r.appendf("Discard FrameBuffer support: %s\n", (fDiscardFBSupport ? "YES" : "NO"));
r.appendf("Full screen clear is free: %s\n", (fFullClearIsFree ? "YES" : "NO"));
r.appendf("Drops tile on zero divide: %s\n", (fDropsTileOnZeroDivide ? "YES" : "NO"));
return r;
}

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@ -250,6 +250,8 @@ public:
bool fullClearIsFree() const { return fFullClearIsFree; }
bool dropsTileOnZeroDivide() const { return fDropsTileOnZeroDivide; }
private:
/**
* Maintains a bit per GrPixelConfig. It is used to avoid redundantly
@ -332,6 +334,7 @@ private:
bool fFixedFunctionSupport : 1;
bool fDiscardFBSupport : 1;
bool fFullClearIsFree : 1;
bool fDropsTileOnZeroDivide : 1;
typedef GrDrawTargetCaps INHERITED;
};