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https://github.com/mozilla/gecko-dev.git
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88 lines
1.8 KiB
C++
88 lines
1.8 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef MOZILLA_GFX_TOOLS_H_
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#define MOZILLA_GFX_TOOLS_H_
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#include "Types.h"
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#include "Point.h"
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#include <math.h>
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#if defined(_MSC_VER) && (_MSC_VER < 1600)
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#define hypotf _hypotf
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#endif
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namespace mozilla {
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namespace gfx {
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static inline bool
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IsOperatorBoundByMask(CompositionOp aOp) {
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switch (aOp) {
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case OP_IN:
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case OP_OUT:
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case OP_DEST_IN:
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case OP_DEST_ATOP:
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case OP_SOURCE:
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return false;
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default:
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return true;
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}
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}
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template <class T>
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struct ClassStorage
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{
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char bytes[sizeof(T)];
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const T *addr() const { return (const T *)bytes; }
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T *addr() { return (T *)(void *)bytes; }
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};
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static inline bool
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FuzzyEqual(Float aA, Float aB, Float aErr)
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{
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if ((aA + aErr > aB) && (aA - aErr < aB)) {
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return true;
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}
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return false;
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}
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static inline void
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NudgeToInteger(float *aVal)
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{
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float r = floorf(*aVal + 0.5f);
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// The error threshold should be proportional to the rounded value. This
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// bounds the relative error introduced by the nudge operation. However,
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// when the rounded value is 0, the error threshold can't be proportional
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// to the rounded value (we'd never round), so we just choose the same
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// threshold as for a rounded value of 1.
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if (FuzzyEqual(r, *aVal, r == 0.0f ? 1e-6f : fabs(r*1e-6f))) {
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*aVal = r;
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}
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}
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static inline Float
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Distance(Point aA, Point aB)
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{
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return hypotf(aB.x - aA.x, aB.y - aA.y);
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}
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static inline int
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BytesPerPixel(SurfaceFormat aFormat)
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{
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switch (aFormat) {
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case FORMAT_A8:
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return 1;
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case FORMAT_R5G6B5:
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return 2;
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default:
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return 4;
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}
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}
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}
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}
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#endif /* MOZILLA_GFX_TOOLS_H_ */
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