ebiten/internal/graphicsdriver/opengl/pbo_desktop.go
2020-01-01 01:57:12 +09:00

60 lines
1.6 KiB
Go

// Copyright 2019 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build darwin freebsd linux windows
// +build !js
// +build !android
// +build !ios
package opengl
import (
"reflect"
"unsafe"
"github.com/hajimehoshi/ebiten/internal/driver"
)
const canUsePBO = true
func drawPixelsWithPBO(img *Image, args []*driver.ReplacePixelsArgs) {
w, h := img.width, img.height
if img.pbo == *new(buffer) {
img.pbo = img.driver.context.newPixelBufferObject(w, h)
}
if img.pbo == *new(buffer) {
panic("opengl: newPixelBufferObject failed")
}
mappedPBO := img.driver.context.mapPixelBuffer(img.pbo)
if mappedPBO == 0 {
panic("opengl: mapPixelBuffer failed")
}
var mapped []byte
sh := (*reflect.SliceHeader)(unsafe.Pointer(&mapped))
sh.Data = mappedPBO
sh.Len = 4 * w * h
sh.Cap = 4 * w * h
for _, a := range args {
stride := 4 * w
offset := 4 * (a.Y*w + a.X)
for j := 0; j < a.Height; j++ {
copy(mapped[offset+stride*j:offset+stride*j+4*a.Width], a.Pixels[4*a.Width*j:4*a.Width*(j+1)])
}
}
img.driver.context.unmapPixelBuffer(img.pbo, img.textureNative, w, h)
}