static GrTexture* copy_on_gpu(GrTexture* inputTexture, const SkIRect* subset, const CopyParams& copyParams) { SkASSERT(!subset || !subset->isEmpty()); GrContext* context = inputTexture->getContext(); SkASSERT(context); GrPixelConfig config = GrMakePixelConfigUncompressed(inputTexture->config()); sk_sp<GrDrawContext> copyDC = context->makeDrawContextWithFallback(SkBackingFit::kExact, copyParams.fWidth, copyParams.fHeight, config, nullptr); if (!copyDC) { return nullptr; } GrPaint paint; paint.setGammaCorrect(true); SkScalar sx SK_INIT_TO_AVOID_WARNING; SkScalar sy SK_INIT_TO_AVOID_WARNING; if (subset) { sx = 1.f / inputTexture->width(); sy = 1.f / inputTexture->height(); } if (copyParams.fFilter != GrTextureParams::kNone_FilterMode && subset && (subset->width() != copyParams.fWidth || subset->height() != copyParams.fHeight)) { SkRect domain; domain.fLeft = (subset->fLeft + 0.5f) * sx; domain.fTop = (subset->fTop + 0.5f)* sy; domain.fRight = (subset->fRight - 0.5f) * sx; domain.fBottom = (subset->fBottom - 0.5f) * sy; // This would cause us to read values from outside the subset. Surely, the caller knows // better! SkASSERT(copyParams.fFilter != GrTextureParams::kMipMap_FilterMode); paint.addColorFragmentProcessor( GrTextureDomainEffect::Make(inputTexture, nullptr, SkMatrix::I(), domain, GrTextureDomain::kClamp_Mode, copyParams.fFilter)); } else { GrTextureParams params(SkShader::kClamp_TileMode, copyParams.fFilter); paint.addColorTextureProcessor(inputTexture, nullptr, SkMatrix::I(), params); } paint.setPorterDuffXPFactory(SkBlendMode::kSrc); SkRect localRect; if (subset) { localRect = SkRect::Make(*subset); localRect.fLeft *= sx; localRect.fTop *= sy; localRect.fRight *= sx; localRect.fBottom *= sy; } else { localRect = SkRect::MakeWH(1.f, 1.f); } SkRect dstRect = SkRect::MakeIWH(copyParams.fWidth, copyParams.fHeight); copyDC->fillRectToRect(GrNoClip(), paint, SkMatrix::I(), dstRect, localRect); return copyDC->asTexture().release(); }