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https://github.com/hajimehoshi/ebiten.git
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3691083cee
This change is based on @silbinarywolf's change: https://github.com/hajimehoshi/ebiten/issues/798#issuecomment-457822280 Fixes #798
51 lines
1.4 KiB
Go
51 lines
1.4 KiB
Go
// Copyright 2019 The Ebiten Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package clock
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import (
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"fmt"
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"unsafe"
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"golang.org/x/sys/windows"
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)
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var (
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kernel32 = windows.NewLazySystemDLL("kernel32")
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)
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var (
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procQueryPerformanceFrequency = kernel32.NewProc("QueryPerformanceFrequency")
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procQueryPerformanceCounter = kernel32.NewProc("QueryPerformanceCounter")
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)
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var freq int64
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func init() {
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_, _, e := procQueryPerformanceFrequency.Call(uintptr(unsafe.Pointer(&freq)))
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if e != nil && e.(windows.Errno) != 0 {
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panic(fmt.Sprintf("clock: QueryPerformanceFrequency failed: errno: %d", e.(windows.Errno)))
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}
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}
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func now() int64 {
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var ctr int64
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// TODO: Should the returned value be checked?
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_, _, e := procQueryPerformanceCounter.Call(uintptr(unsafe.Pointer(&ctr)))
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if e != nil && e.(windows.Errno) != 0 {
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panic(fmt.Sprintf("clock: QueryPerformanceCounter failed: errno: %d", e.(windows.Errno)))
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}
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return (ctr * 1e9) / freq
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}
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