Exemplo n.º 1
0
// Create a mask of 'devPath' and place the result in 'mask'.
static GrTexture* create_mask_GPU(GrContext* context,
                                  const SkRect& maskRect,
                                  const SkPath& devPath,
                                  const GrStrokeInfo& strokeInfo,
                                  bool doAA,
                                  int sampleCnt) {
    GrSurfaceDesc desc;
    desc.fFlags = kRenderTarget_GrSurfaceFlag;
    desc.fWidth = SkScalarCeilToInt(maskRect.width());
    desc.fHeight = SkScalarCeilToInt(maskRect.height());
    desc.fSampleCnt = doAA ? sampleCnt : 0;
    // We actually only need A8, but it often isn't supported as a
    // render target so default to RGBA_8888
    desc.fConfig = kRGBA_8888_GrPixelConfig;

    if (context->caps()->isConfigRenderable(kAlpha_8_GrPixelConfig, desc.fSampleCnt > 0)) {
        desc.fConfig = kAlpha_8_GrPixelConfig;
    }

    GrTexture* mask = context->textureProvider()->createApproxTexture(desc);
    if (nullptr == mask) {
        return nullptr;
    }

    SkRect clipRect = SkRect::MakeWH(maskRect.width(), maskRect.height());

    GrDrawContext* drawContext = context->drawContext();
    if (!drawContext) {
        return nullptr;
    }

    drawContext->clear(mask->asRenderTarget(), nullptr, 0x0, true);

    GrPaint tempPaint;
    tempPaint.setAntiAlias(doAA);
    tempPaint.setCoverageSetOpXPFactory(SkRegion::kReplace_Op);

    // setup new clip
    GrClip clip(clipRect);

    // Draw the mask into maskTexture with the path's top-left at the origin using tempPaint.
    SkMatrix translate;
    translate.setTranslate(-maskRect.fLeft, -maskRect.fTop);
    drawContext->drawPath(mask->asRenderTarget(), clip, tempPaint, translate, devPath, strokeInfo);
    return mask;
}