diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/GrDistanceFieldTextContext.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/GrDistanceFieldTextContext.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,458 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrDistanceFieldTextContext.h"
+#include "GrAtlas.h"
+#include "GrDrawTarget.h"
+#include "GrDrawTargetCaps.h"
+#include "GrFontScaler.h"
+#include "SkGlyphCache.h"
+#include "GrIndexBuffer.h"
+#include "GrTextStrike.h"
+#include "GrTextStrike_impl.h"
+#include "SkDraw.h"
+#include "SkGpuDevice.h"
+#include "SkPath.h"
+#include "SkRTConf.h"
+#include "SkStrokeRec.h"
+#include "effects/GrDistanceFieldTextureEffect.h"
+
+static const int kGlyphCoordsAttributeIndex = 1;
+
+static const int kBaseDFFontSize = 32;
+
+SK_CONF_DECLARE(bool, c_DumpFontCache, "gpu.dumpFontCache", false,
+                "Dump the contents of the font cache before every purge.");
+
+#if SK_FORCE_DISTANCEFIELD_FONTS
+static const bool kForceDistanceFieldFonts = true;
+#else
+static const bool kForceDistanceFieldFonts = false;
+#endif
+
+GrDistanceFieldTextContext::GrDistanceFieldTextContext(GrContext* context,
+                                                       const SkDeviceProperties& properties)
+                                                    : GrTextContext(context, properties) {
+    fStrike = NULL;
+
+    fCurrTexture = NULL;
+    fCurrVertex = 0;
+
+    fVertices = NULL;
+    fMaxVertices = 0;
+}
+
+GrDistanceFieldTextContext::~GrDistanceFieldTextContext() {
+    this->flushGlyphs();
+}
+
+bool GrDistanceFieldTextContext::canDraw(const SkPaint& paint) {
+    return (kForceDistanceFieldFonts || paint.isDistanceFieldTextTEMP()) &&
+           !paint.getRasterizer() && !paint.getMaskFilter() &&
+           paint.getStyle() == SkPaint::kFill_Style &&
+           fContext->getTextTarget()->caps()->shaderDerivativeSupport() &&
+           !SkDraw::ShouldDrawTextAsPaths(paint, fContext->getMatrix());
+}
+
+static inline GrColor skcolor_to_grcolor_nopremultiply(SkColor c) {
+    unsigned r = SkColorGetR(c);
+    unsigned g = SkColorGetG(c);
+    unsigned b = SkColorGetB(c);
+    return GrColorPackRGBA(r, g, b, 0xff);
+}
+
+void GrDistanceFieldTextContext::flushGlyphs() {
+    if (NULL == fDrawTarget) {
+        return;
+    }
+
+    GrDrawState* drawState = fDrawTarget->drawState();
+    GrDrawState::AutoRestoreEffects are(drawState);
+    drawState->setFromPaint(fPaint, fContext->getMatrix(), fContext->getRenderTarget());
+
+    if (fCurrVertex > 0) {
+        // setup our sampler state for our text texture/atlas
+        SkASSERT(GrIsALIGN4(fCurrVertex));
+        SkASSERT(fCurrTexture);
+        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();
+
+        if (!GrPixelConfigIsAlphaOnly(fCurrTexture->config())) {
+            if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||
+                kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() ||
+                fPaint.numColorStages()) {
+                GrPrintf("LCD Text will not draw correctly.\n");
+            }
+            // We don't use the GrPaint's color in this case because it's been premultiplied by
+            // alpha. Instead we feed in a non-premultiplied color, and multiply its alpha by
+            // the mask texture color. The end result is that we get
+            //            mask*paintAlpha*paintColor + (1-mask*paintAlpha)*dstColor
+            int a = SkColorGetA(fSkPaint.getColor());
+            // paintAlpha
+            drawState->setColor(SkColorSetARGB(a, a, a, a));
+            // paintColor
+            drawState->setBlendConstant(skcolor_to_grcolor_nopremultiply(fSkPaint.getColor()));
+            drawState->setBlendFunc(kConstC_GrBlendCoeff, kISC_GrBlendCoeff);
+        } else {
+            // set back to normal in case we took LCD path previously.
+            drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
+            drawState->setColor(fPaint.getColor());
+        }
+
+        int nGlyphs = fCurrVertex / 4;
+        fDrawTarget->setIndexSourceToBuffer(fContext->getQuadIndexBuffer());
+        fDrawTarget->drawIndexedInstances(kTriangles_GrPrimitiveType,
+                                          nGlyphs,
+                                          4, 6);
+        fDrawTarget->resetVertexSource();
+        fVertices = NULL;
+        fMaxVertices = 0;
+        fCurrVertex = 0;
+        SkSafeSetNull(fCurrTexture);
+    }
+}
+
+namespace {
+
+// position + texture coord
+extern const GrVertexAttrib gTextVertexAttribs[] = {
+    {kVec2f_GrVertexAttribType, 0,               kPosition_GrVertexAttribBinding},
+    {kVec2f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding}
+};
+
+};
+
+void GrDistanceFieldTextContext::drawPackedGlyph(GrGlyph::PackedID packed,
+                                                 GrFixed vx, GrFixed vy,
+                                                 GrFontScaler* scaler) {
+    if (NULL == fDrawTarget) {
+        return;
+    }
+    if (NULL == fStrike) {
+        fStrike = fContext->getFontCache()->getStrike(scaler, true);
+    }
+
+    GrGlyph* glyph = fStrike->getGlyph(packed, scaler);
+    if (NULL == glyph || glyph->fBounds.isEmpty()) {
+        return;
+    }
+
+    SkScalar sx = SkFixedToScalar(vx);
+    SkScalar sy = SkFixedToScalar(vy);
+/*
+    // not valid, need to find a different solution for this
+    vx += SkIntToFixed(glyph->fBounds.fLeft);
+    vy += SkIntToFixed(glyph->fBounds.fTop);
+
+    // keep them as ints until we've done the clip-test
+    GrFixed width = glyph->fBounds.width();
+    GrFixed height = glyph->fBounds.height();
+
+    // check if we clipped out
+    if (true || NULL == glyph->fPlot) {
+        int x = vx >> 16;
+        int y = vy >> 16;
+        if (fClipRect.quickReject(x, y, x + width, y + height)) {
+//            SkCLZ(3);    // so we can set a break-point in the debugger
+            return;
+        }
+    }
+*/
+    if (NULL == glyph->fPlot) {
+        if (fStrike->addGlyphToAtlas(glyph, scaler)) {
+            goto HAS_ATLAS;
+        }
+
+        // try to clear out an unused plot before we flush
+        if (fContext->getFontCache()->freeUnusedPlot(fStrike) &&
+            fStrike->addGlyphToAtlas(glyph, scaler)) {
+            goto HAS_ATLAS;
+        }
+
+        if (c_DumpFontCache) {
+#ifdef SK_DEVELOPER
+            fContext->getFontCache()->dump();
+#endif
+        }
+
+        // before we purge the cache, we must flush any accumulated draws
+        this->flushGlyphs();
+        fContext->flush();
+
+        // we should have an unused plot now
+        if (fContext->getFontCache()->freeUnusedPlot(fStrike) &&
+            fStrike->addGlyphToAtlas(glyph, scaler)) {
+            goto HAS_ATLAS;
+        }
+
+        if (NULL == glyph->fPath) {
+            SkPath* path = SkNEW(SkPath);
+            if (!scaler->getGlyphPath(glyph->glyphID(), path)) {
+                // flag the glyph as being dead?
+                delete path;
+                return;
+            }
+            glyph->fPath = path;
+        }
+
+        GrContext::AutoMatrix am;
+        SkMatrix translate;
+        translate.setTranslate(sx, sy);
+        GrPaint tmpPaint(fPaint);
+        am.setPreConcat(fContext, translate, &tmpPaint);
+        SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
+        fContext->drawPath(tmpPaint, *glyph->fPath, stroke);
+        return;
+    }
+
+HAS_ATLAS:
+    SkASSERT(glyph->fPlot);
+    GrDrawTarget::DrawToken drawToken = fDrawTarget->getCurrentDrawToken();
+    glyph->fPlot->setDrawToken(drawToken);
+
+    GrTexture* texture = glyph->fPlot->texture();
+    SkASSERT(texture);
+
+    if (fCurrTexture != texture || fCurrVertex + 4 > fMaxVertices) {
+        this->flushGlyphs();
+        fCurrTexture = texture;
+        fCurrTexture->ref();
+    }
+
+    if (NULL == fVertices) {
+       // If we need to reserve vertices allow the draw target to suggest
+        // a number of verts to reserve and whether to perform a flush.
+        fMaxVertices = kMinRequestedVerts;
+        fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
+            SK_ARRAY_COUNT(gTextVertexAttribs));
+        bool flush = fDrawTarget->geometryHints(&fMaxVertices, NULL);
+        if (flush) {
+            this->flushGlyphs();
+            fContext->flush();
+            fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
+                SK_ARRAY_COUNT(gTextVertexAttribs));
+        }
+        fMaxVertices = kDefaultRequestedVerts;
+        // ignore return, no point in flushing again.
+        fDrawTarget->geometryHints(&fMaxVertices, NULL);
+
+        int maxQuadVertices = 4 * fContext->getQuadIndexBuffer()->maxQuads();
+        if (fMaxVertices < kMinRequestedVerts) {
+            fMaxVertices = kDefaultRequestedVerts;
+        } else if (fMaxVertices > maxQuadVertices) {
+            // don't exceed the limit of the index buffer
+            fMaxVertices = maxQuadVertices;
+        }
+        bool success = fDrawTarget->reserveVertexAndIndexSpace(fMaxVertices,
+                                                               0,
+                                                               GrTCast<void**>(&fVertices),
+                                                               NULL);
+        GrAlwaysAssert(success);
+        SkASSERT(2*sizeof(GrPoint) == fDrawTarget->getDrawState().getVertexSize());
+    }
+
+    SkScalar dx = SkIntToScalar(glyph->fBounds.fLeft);
+    SkScalar dy = SkIntToScalar(glyph->fBounds.fTop);
+    SkScalar width = SkIntToScalar(glyph->fBounds.width());
+    SkScalar height = SkIntToScalar(glyph->fBounds.height());
+
+    SkScalar scale = fTextRatio;
+    dx *= scale;
+    dy *= scale;
+    sx += dx;
+    sy += dy;
+    width *= scale;
+    height *= scale;
+
+    GrFixed tx = SkIntToFixed(glyph->fAtlasLocation.fX);
+    GrFixed ty = SkIntToFixed(glyph->fAtlasLocation.fY);
+    GrFixed tw = SkIntToFixed(glyph->fBounds.width());
+    GrFixed th = SkIntToFixed(glyph->fBounds.height());
+
+    static const size_t kVertexSize = 2 * sizeof(SkPoint);
+    fVertices[2*fCurrVertex].setRectFan(sx,
+                                        sy,
+                                        sx + width,
+                                        sy + height,
+                                        kVertexSize);
+    fVertices[2*fCurrVertex+1].setRectFan(SkFixedToFloat(texture->normalizeFixedX(tx)),
+                                          SkFixedToFloat(texture->normalizeFixedY(ty)),
+                                          SkFixedToFloat(texture->normalizeFixedX(tx + tw)),
+                                          SkFixedToFloat(texture->normalizeFixedY(ty + th)),
+                                          kVertexSize);
+    fCurrVertex += 4;
+}
+
+inline void GrDistanceFieldTextContext::init(const GrPaint& paint, const SkPaint& skPaint) {
+    GrTextContext::init(paint, skPaint);
+
+    fStrike = NULL;
+
+    fCurrTexture = NULL;
+    fCurrVertex = 0;
+
+    fVertices = NULL;
+    fMaxVertices = 0;
+
+    fTextRatio = fSkPaint.getTextSize()/kBaseDFFontSize;
+
+    fSkPaint.setTextSize(SkIntToScalar(kBaseDFFontSize));
+    fSkPaint.setLCDRenderText(false);
+    fSkPaint.setAutohinted(false);
+    fSkPaint.setSubpixelText(true);
+}
+
+inline void GrDistanceFieldTextContext::finish() {
+    flushGlyphs();
+
+    GrTextContext::finish();
+}
+
+void GrDistanceFieldTextContext::drawText(const GrPaint& paint, const SkPaint& skPaint,
+                                          const char text[], size_t byteLength,
+                                          SkScalar x, SkScalar y) {
+    SkASSERT(byteLength == 0 || text != NULL);
+
+    // nothing to draw or can't draw
+    if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/
+        || fSkPaint.getRasterizer()) {
+        return;
+    }
+
+    this->init(paint, skPaint);
+
+    SkScalar sizeRatio = fTextRatio;
+
+    SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();
+
+    SkAutoGlyphCache    autoCache(fSkPaint, &fDeviceProperties, NULL);
+    SkGlyphCache*       cache = autoCache.getCache();
+    GrFontScaler*       fontScaler = GetGrFontScaler(cache);
+
+    // need to measure first
+    // TODO - generate positions and pre-load cache as well?
+    const char* stop = text + byteLength;
+    if (fSkPaint.getTextAlign() != SkPaint::kLeft_Align) {
+        SkFixed    stopX = 0;
+        SkFixed    stopY = 0;
+
+        const char* textPtr = text;
+        while (textPtr < stop) {
+            // don't need x, y here, since all subpixel variants will have the
+            // same advance
+            const SkGlyph& glyph = glyphCacheProc(cache, &textPtr, 0, 0);
+
+            stopX += glyph.fAdvanceX;
+            stopY += glyph.fAdvanceY;
+        }
+        SkASSERT(textPtr == stop);
+
+        SkScalar alignX = SkFixedToScalar(stopX)*sizeRatio;
+        SkScalar alignY = SkFixedToScalar(stopY)*sizeRatio;
+
+        if (fSkPaint.getTextAlign() == SkPaint::kCenter_Align) {
+            alignX = SkScalarHalf(alignX);
+            alignY = SkScalarHalf(alignY);
+        }
+
+        x -= alignX;
+        y -= alignY;
+    }
+
+    SkFixed fx = SkScalarToFixed(x) + SK_FixedHalf;
+    SkFixed fy = SkScalarToFixed(y) + SK_FixedHalf;
+    SkFixed fixedScale = SkScalarToFixed(sizeRatio);
+    while (text < stop) {
+        const SkGlyph& glyph = glyphCacheProc(cache, &text, fx, fy);
+
+        if (glyph.fWidth) {
+            this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                glyph.getSubXFixed(),
+                                                glyph.getSubYFixed()),
+                                  SkFixedFloorToFixed(fx),
+                                  SkFixedFloorToFixed(fy),
+                                  fontScaler);
+        }
+
+        fx += SkFixedMul_portable(glyph.fAdvanceX, fixedScale);
+        fy += SkFixedMul_portable(glyph.fAdvanceY, fixedScale);
+    }
+
+    this->finish();
+}
+
+void GrDistanceFieldTextContext::drawPosText(const GrPaint& paint, const SkPaint& skPaint,
+                                             const char text[], size_t byteLength,
+                                             const SkScalar pos[], SkScalar constY,
+                                             int scalarsPerPosition) {
+
+    SkASSERT(byteLength == 0 || text != NULL);
+    SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
+
+    // nothing to draw
+    if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/) {
+        return;
+    }
+
+    this->init(paint, skPaint);
+
+    SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();
+
+    SkAutoGlyphCache    autoCache(fSkPaint, &fDeviceProperties, NULL);
+    SkGlyphCache*       cache = autoCache.getCache();
+    GrFontScaler*       fontScaler = GetGrFontScaler(cache);
+
+    const char*        stop = text + byteLength;
+
+    if (SkPaint::kLeft_Align == fSkPaint.getTextAlign()) {
+        while (text < stop) {
+            // the last 2 parameters are ignored
+            const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
+
+            if (glyph.fWidth) {
+                SkScalar x = pos[0];
+                SkScalar y = scalarsPerPosition == 1 ? constY : pos[1];
+
+                this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                    glyph.getSubXFixed(),
+                                                    glyph.getSubYFixed()),
+                                      SkScalarToFixed(x) + SK_FixedHalf, //d1g.fHalfSampleX,
+                                      SkScalarToFixed(y) + SK_FixedHalf, //d1g.fHalfSampleY,
+                                      fontScaler);
+            }
+            pos += scalarsPerPosition;
+        }
+    } else {
+        int alignShift = SkPaint::kCenter_Align == fSkPaint.getTextAlign() ? 1 : 0;
+        while (text < stop) {
+            // the last 2 parameters are ignored
+            const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
+
+            if (glyph.fWidth) {
+                SkScalar x = pos[0];
+                SkScalar y = scalarsPerPosition == 1 ? constY : pos[1];
+
+                this->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                    glyph.getSubXFixed(),
+                                                    glyph.getSubYFixed()),
+                                      SkScalarToFixed(x) - (glyph.fAdvanceX >> alignShift)
+                                        + SK_FixedHalf, //d1g.fHalfSampleX,
+                                      SkScalarToFixed(y) - (glyph.fAdvanceY >> alignShift)
+                                        + SK_FixedHalf, //d1g.fHalfSampleY,
+                                      fontScaler);
+            }
+            pos += scalarsPerPosition;
+        }
+    }
+
+    this->finish();
+}