C++ GrDrawState::addCoverageEffect方法代码示例

void GrSWMaskHelper::DrawToTargetWithPathMask(GrTexture* texture,
        GrDrawTarget* target,
        const SkIRect& rect) {
    GrDrawState* drawState = target->drawState();

    GrDrawState::AutoViewMatrixRestore avmr;
    if (!avmr.setIdentity(drawState)) {
        return;
    }
    GrDrawState::AutoRestoreEffects are(drawState);

    SkRect dstRect = SkRect::MakeLTRB(SK_Scalar1 * rect.fLeft,
                                      SK_Scalar1 * rect.fTop,
                                      SK_Scalar1 * rect.fRight,
                                      SK_Scalar1 * rect.fBottom);

    // We want to use device coords to compute the texture coordinates. We set our matrix to be
    // equal to the view matrix followed by a translation so that the top-left of the device bounds
    // maps to 0,0, and then a scaling matrix to normalized coords. We apply this matrix to the
    // vertex positions rather than local coords.
    SkMatrix maskMatrix;
    maskMatrix.setIDiv(texture->width(), texture->height());
    maskMatrix.preTranslate(SkIntToScalar(-rect.fLeft), SkIntToScalar(-rect.fTop));
    maskMatrix.preConcat(drawState->getViewMatrix());

    drawState->addCoverageEffect(
        GrSimpleTextureEffect::Create(texture,
                                      maskMatrix,
                                      GrTextureParams::kNone_FilterMode,
                                      kPosition_GrCoordSet))->unref();

    target->drawSimpleRect(dstRect);
}

void GrBitmapTextContext::flushGlyphs() {
    if (NULL == fDrawTarget) {
        return;
    }

    GrDrawState* drawState = fDrawTarget->drawState();
    GrDrawState::AutoRestoreEffects are(drawState);
    drawState->setFromPaint(fPaint, SkMatrix::I(), fContext->getRenderTarget());

    if (fCurrVertex > 0) {
        // setup our sampler state for our text texture/atlas
        SkASSERT(SkIsAlign4(fCurrVertex));
        SkASSERT(fCurrTexture);
        GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kNone_FilterMode);

        // This effect could be stored with one of the cache objects (atlas?)
        drawState->addCoverageEffect(
                                GrCustomCoordsTextureEffect::Create(fCurrTexture, params),
                                kGlyphCoordsAttributeIndex)->unref();

        if (NULL != fStrike && kARGB_GrMaskFormat == fStrike->getMaskFormat()) {
            drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
            drawState->setColor(0xffffffff);
        } else 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, &fVertexBounds);

        fDrawTarget->resetVertexSource();
        fVertices = NULL;
        fMaxVertices = 0;
        fCurrVertex = 0;
        fVertexBounds.setLargestInverted();
        SkSafeSetNull(fCurrTexture);
    }
}

//.........这里部分代码省略.........

    SkScalar devBloat = useAA ? 0.5f : 0.f;

    GrDrawState* drawState = target->drawState();
    if (devIntervals[1] <= 0.f && useAA) {
        // Case when we end up drawing a solid AA rect
        // Reset the start rect to draw this single solid rect
        // but it requires to upload a new intervals uniform so we can mimic
        // one giant dash
        ptsRot[0].fX -= hasStartRect ? startAdj : 0;
        ptsRot[1].fX += hasEndRect ? endAdj : 0;
        startRect.set(ptsRot, 2);
        startRect.outset(strokeAdj, halfSrcStroke);
        hasStartRect = true;
        hasEndRect = false;
        lineDone = true;

        SkPoint devicePts[2];
        vm.mapPoints(devicePts, ptsRot, 2);
        SkScalar lineLength = SkPoint::Distance(devicePts[0], devicePts[1]);
        if (hasCap) {
            lineLength += 2.f * halfDevStroke;
        }
        devIntervals[0] = lineLength;
    }
    if (devIntervals[1] > 0.f || useAA) {
        SkPathEffect::DashInfo devInfo;
        devInfo.fPhase = devPhase;
        devInfo.fCount = 2;
        devInfo.fIntervals = devIntervals;
        GrEffectEdgeType edgeType= useAA ? kFillAA_GrEffectEdgeType :
            kFillBW_GrEffectEdgeType;
        bool isRoundCap = SkPaint::kRound_Cap == cap;
        GrDashingEffect::DashCap capType = isRoundCap ? GrDashingEffect::kRound_DashCap :
                                                        GrDashingEffect::kNonRound_DashCap;
        drawState->addCoverageEffect(
            GrDashingEffect::Create(edgeType, devInfo, strokeWidth, capType), 1)->unref();
    }

    // Set up the vertex data for the line and start/end dashes
    drawState->setVertexAttribs<gDashLineVertexAttribs>(SK_ARRAY_COUNT(gDashLineVertexAttribs));

    int totalRectCnt = 0;

    totalRectCnt += !lineDone ? 1 : 0;
    totalRectCnt += hasStartRect ? 1 : 0;
    totalRectCnt += hasEndRect ? 1 : 0;

    GrDrawTarget::AutoReleaseGeometry geo(target, totalRectCnt * 4, 0);
    if (!geo.succeeded()) {
        GrPrintf("Failed to get space for vertices!\n");
        return false;
    }

    DashLineVertex* verts = reinterpret_cast<DashLineVertex*>(geo.vertices());

    int curVIdx = 0;

    if (SkPaint::kRound_Cap == cap && 0 != srcStrokeWidth) {
        // need to adjust this for round caps to correctly set the dashPos attrib on vertices
        startOffset -= halfDevStroke;
    }

    // Draw interior part of dashed line
    if (!lineDone) {
        SkPoint devicePts[2];
        vm.mapPoints(devicePts, ptsRot, 2);
        SkScalar lineLength = SkPoint::Distance(devicePts[0], devicePts[1]);
        if (hasCap) {
            lineLength += 2.f * halfDevStroke;
        }

        SkRect bounds;
        bounds.set(ptsRot[0].fX, ptsRot[0].fY, ptsRot[1].fX, ptsRot[1].fY);
        bounds.outset(bloatX + strokeAdj, bloatY + halfSrcStroke);
        setup_dashed_rect(bounds, verts, curVIdx, combinedMatrix, startOffset, devBloat,
                          lineLength, halfDevStroke);
        curVIdx += 4;
    }

    if (hasStartRect) {
        SkASSERT(useAA);  // so that we know bloatX and bloatY have been set
        startRect.outset(bloatX, bloatY);
        setup_dashed_rect(startRect, verts, curVIdx, combinedMatrix, startOffset, devBloat,
                          devIntervals[0], halfDevStroke);
        curVIdx += 4;
    }

    if (hasEndRect) {
        SkASSERT(useAA);  // so that we know bloatX and bloatY have been set
        endRect.outset(bloatX, bloatY);
        setup_dashed_rect(endRect, verts, curVIdx, combinedMatrix, startOffset, devBloat,
                          devIntervals[0], halfDevStroke);
    }

    target->setIndexSourceToBuffer(gpu->getContext()->getQuadIndexBuffer());
    target->drawIndexedInstances(kTriangles_GrPrimitiveType, totalRectCnt, 4, 6);
    target->resetIndexSource();
    return true;
}

void GrBitmapTextContext::flushGlyphs() {
    if (NULL == fDrawTarget) {
        return;
    }

    GrDrawState* drawState = fDrawTarget->drawState();
    GrDrawState::AutoRestoreEffects are(drawState);
    drawState->setFromPaint(fPaint, SkMatrix::I(), fContext->getRenderTarget());

    if (fCurrVertex > 0) {
        // setup our sampler state for our text texture/atlas
        SkASSERT(SkIsAlign4(fCurrVertex));
        SkASSERT(fCurrTexture);
        GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kNone_FilterMode);

        uint32_t textureUniqueID = fCurrTexture->getUniqueID();
        
        if (textureUniqueID != fEffectTextureUniqueID) {
            fCachedEffect.reset(GrCustomCoordsTextureEffect::Create(fCurrTexture, params));
            fEffectTextureUniqueID = textureUniqueID;
        }

        // This effect could be stored with one of the cache objects (atlas?)
        int coordsIdx = drawState->hasColorVertexAttribute() ? kGlyphCoordsWithColorAttributeIndex :
                                                               kGlyphCoordsNoColorAttributeIndex;
        drawState->addCoverageEffect(fCachedEffect.get(), coordsIdx);
        SkASSERT(NULL != fStrike);
        switch (fStrike->getMaskFormat()) {
            // Color bitmap text
            case kARGB_GrMaskFormat:
                SkASSERT(!drawState->hasColorVertexAttribute());
                drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
                drawState->setColor(0xffffffff);
                break;
            // LCD text
            case kA888_GrMaskFormat:
            case kA565_GrMaskFormat: {
                if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||
                    kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() ||
                    fPaint.numColorStages()) {
                    GrPrintf("LCD Text will not draw correctly.\n");
                }
                SkASSERT(!drawState->hasColorVertexAttribute());
                // 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);
                break;
            }
            // Grayscale/BW text
            case kA8_GrMaskFormat:
                // set back to normal in case we took LCD path previously.
                drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
                // We're using per-vertex color.
                SkASSERT(drawState->hasColorVertexAttribute());
                break;
            default:
                SkFAIL("Unexepected mask format.");
        }
        int nGlyphs = fCurrVertex / 4;
        fDrawTarget->setIndexSourceToBuffer(fContext->getQuadIndexBuffer());
        fDrawTarget->drawIndexedInstances(kTriangles_GrPrimitiveType,
                                          nGlyphs,
                                          4, 6, &fVertexBounds);

        fDrawTarget->resetVertexSource();
        fVertices = NULL;
        fMaxVertices = 0;
        fCurrVertex = 0;
        fVertexBounds.setLargestInverted();
        SkSafeSetNull(fCurrTexture);
    }
}