| // Copyright (C) 2015 The Android Open Source Project |
| // |
| // 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 image |
| |
| import "fmt" |
| |
| // Format is the interface for an image and/or pixel format. |
| // |
| // Check returns an error if the combination of data, image width and image |
| // height is invalid for the given format, otherwise Check returns nil. |
| type Format interface { |
| Check(data []byte, width, height int) error |
| } |
| |
| func checkSize(data []byte, width, height int, bpp int) error { |
| expected := width * height * bpp / 8 |
| actual := len(data) |
| if expected != actual { |
| return fmt.Errorf("Image data size (0x%x) did not match expected (0x%x) for dimensions %dx%d\n", |
| actual, expected, width, height) |
| } |
| return nil |
| } |
| |
| type fmtRGBA struct{} |
| |
| func (fmtRGBA) String() string { return "RGBA" } |
| func (fmtRGBA) Check(d []byte, w, h int) error { return checkSize(d, w, h, 32) } |
| |
| // RGBA returns a format containing an 8-bit red, green, blue and alpha channel |
| // per pixel. |
| func RGBA() Format { return fmtRGBA{} } |