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8459af91d6
During some new development work that might make transform resets more expensive we realized that the resets were mostly coming from the calls to snap the transform to a pixel translate value and many of those were NOPs since the transform was already on a pixel translate value. This PR will avoid those trivially unnecessary reset operations.
71 lines
2.3 KiB
C++
71 lines
2.3 KiB
C++
// Copyright 2013 The Flutter Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "flutter/flow/raster_cache_util.h"
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namespace flutter {
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bool RasterCacheUtil::ComputeIntegralTransCTM(const SkMatrix& in,
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SkMatrix* out) {
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// Avoid integral snapping if the matrix has complex transformation to avoid
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// the artifact observed in https://github.com/flutter/flutter/issues/41654.
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if (!in.isScaleTranslate()) {
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return false;
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}
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SkScalar in_tx = in.getTranslateX();
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SkScalar in_ty = in.getTranslateY();
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SkScalar out_tx = SkScalarRoundToScalar(in_tx);
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SkScalar out_ty = SkScalarRoundToScalar(in_ty);
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if (out_tx != in_tx || out_ty != in_ty) {
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// As a side effect of those tests we also know that neither translation
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// component was a NaN
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*out = in;
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(*out)[SkMatrix::kMTransX] = out_tx;
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(*out)[SkMatrix::kMTransY] = out_ty;
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return true;
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}
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return false;
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}
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bool RasterCacheUtil::ComputeIntegralTransCTM(const SkM44& in, SkM44* out) {
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// Avoid integral snapping if the matrix has complex transformation to avoid
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// the artifact observed in https://github.com/flutter/flutter/issues/41654.
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if (in.rc(0, 1) != 0 || in.rc(0, 2) != 0) {
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// X multiplied by either Y or Z
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return false;
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}
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if (in.rc(1, 0) != 0 || in.rc(1, 2) != 0) {
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// Y multiplied by either X or Z
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return false;
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}
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if (in.rc(3, 0) != 0 || in.rc(3, 1) != 0 || in.rc(3, 2) != 0 ||
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in.rc(3, 3) != 1) {
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// W not identity row, therefore perspective is applied
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return false;
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}
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// We do not need to worry about the Z row unless the W row
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// has perspective entries, which we've just eliminated...
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SkScalar in_tx = in.rc(0, 3);
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SkScalar in_ty = in.rc(1, 3);
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SkScalar out_tx = SkScalarRoundToScalar(in_tx);
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SkScalar out_ty = SkScalarRoundToScalar(in_ty);
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if (out_tx != in_tx || out_ty != in_ty) {
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// As a side effect of those tests we also know that neither translation
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// component was a NaN
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*out = in;
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out->setRC(0, 3, out_tx);
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out->setRC(1, 3, out_ty);
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// No need to worry about Z translation because it has no effect
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// without perspective entries...
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return true;
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}
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return false;
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}
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} // namespace flutter
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