components/viz/service/display/renderer_utils.cc

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/viz/service/display/renderer_utils.h"

#include "third_party/skia/include/core/SkMatrix.h"
#include "third_party/skia/include/core/SkScalar.h"

namespace viz {

static inline bool IsScalarNearlyInteger(SkScalar scalar) {
  return SkScalarNearlyZero(scalar - SkScalarRoundToScalar(scalar));
}

bool IsScaleAndIntegerTranslate(const SkMatrix& matrix) {
  return IsScalarNearlyInteger(matrix[SkMatrix::kMTransX]) &&
         IsScalarNearlyInteger(matrix[SkMatrix::kMTransY]) &&
         SkScalarNearlyZero(matrix[SkMatrix::kMSkewX]) &&
         SkScalarNearlyZero(matrix[SkMatrix::kMSkewY]) &&
         SkScalarNearlyZero(matrix[SkMatrix::kMPersp0]) &&
         SkScalarNearlyZero(matrix[SkMatrix::kMPersp1]) &&
         SkScalarNearlyZero(matrix[SkMatrix::kMPersp2] - 1.0f);
}

}  // namespace viz