mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-13 22:47:26 +01:00
83 lines
1.5 KiB
Go
83 lines
1.5 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.
|
|
|
|
package convert
|
|
|
|
import (
|
|
"io"
|
|
)
|
|
|
|
type Float32Reader interface {
|
|
Read([]float32) (int, error)
|
|
}
|
|
|
|
func NewReaderFromFloat32Reader(r Float32Reader) io.Reader {
|
|
return &f32Reader{r: r}
|
|
}
|
|
|
|
type f32Reader struct {
|
|
r Float32Reader
|
|
eof bool
|
|
buf *byte
|
|
}
|
|
|
|
func max(a, b int) int {
|
|
if a < b {
|
|
return b
|
|
}
|
|
return a
|
|
}
|
|
|
|
func (f *f32Reader) Read(buf []byte) (int, error) {
|
|
if f.eof {
|
|
return 0, io.EOF
|
|
}
|
|
if len(buf) == 0 {
|
|
return 0, nil
|
|
}
|
|
if f.buf != nil {
|
|
buf[0] = *f.buf
|
|
f.buf = nil
|
|
return 1, nil
|
|
}
|
|
|
|
bf := make([]float32, max(len(buf)/2, 1))
|
|
|
|
n, err := f.r.Read(bf)
|
|
if err != nil && err != io.EOF {
|
|
return 0, err
|
|
}
|
|
if err == io.EOF {
|
|
f.eof = true
|
|
}
|
|
|
|
b := buf
|
|
if len(buf) == 1 && n > 0 {
|
|
b = make([]byte, 2)
|
|
}
|
|
for i := 0; i < n; i++ {
|
|
f := bf[i]
|
|
s := int16(f * (1<<15 - 1))
|
|
b[2*i] = uint8(s)
|
|
b[2*i+1] = uint8(s >> 8)
|
|
}
|
|
|
|
if len(buf) == 1 && len(b) == 2 {
|
|
buf[0] = b[0]
|
|
f.buf = &b[1]
|
|
return 1, err
|
|
}
|
|
return n * 2, err
|
|
}
|