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01b8724cfe
avoids the 24.8 quantisation without introducing floating-point equality/rounding behaviour throughout the Wayland state. Closes #1257
81 lines
2.2 KiB
C
81 lines
2.2 KiB
C
/**
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* Looking Glass
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* Copyright © 2017-2026 The Looking Glass Authors
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* https://looking-glass.io
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc., 59
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* Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <stdint.h>
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struct WaylandScale
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{
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int32_t num;
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int32_t den;
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};
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static inline struct WaylandScale waylandScaleFromInt(int32_t scale)
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{
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return (struct WaylandScale) { scale, 1 };
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}
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static inline struct WaylandScale waylandScaleFromRatio(int32_t num, int32_t den)
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{
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return (struct WaylandScale) { num, den };
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}
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static inline bool waylandScaleValid(struct WaylandScale scale)
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{
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return scale.num > 0 && scale.den > 0;
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}
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static inline bool waylandScaleEqual(struct WaylandScale a, struct WaylandScale b)
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{
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return (int64_t)a.num * b.den == (int64_t)b.num * a.den;
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}
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static inline int waylandScaleCmp(struct WaylandScale a, struct WaylandScale b)
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{
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int64_t lhs = (int64_t)a.num * b.den;
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int64_t rhs = (int64_t)b.num * a.den;
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return (lhs > rhs) - (lhs < rhs);
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}
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static inline bool waylandScaleIsFractional(struct WaylandScale scale)
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{
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return waylandScaleValid(scale) && scale.num % scale.den != 0;
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}
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static inline int waylandScaleFloor(struct WaylandScale scale)
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{
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return scale.num / scale.den;
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}
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static inline int waylandScaleCeil(struct WaylandScale scale)
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{
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return (scale.num + scale.den - 1) / scale.den;
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}
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static inline int waylandScaleMulInt(struct WaylandScale scale, int value)
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{
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return (int)(((int64_t)value * scale.num) / scale.den);
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}
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static inline double waylandScaleToDouble(struct WaylandScale scale)
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{
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return (double)scale.num / (double)scale.den;
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}
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