123456789101112131415161718192021222324252627282930313233343536 |
- // Copyright 2014 Hajime Hoshi
- //
- // 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 graphics
- // InternalImageSize returns a nearest appropriate size as an internal image.
- func InternalImageSize(x int) int {
- // minInternalImageSize is the minimum size of internal images (texture/framebuffer).
- //
- // For example, the image size less than 15 is not supported on some iOS devices.
- // See also: https://stackoverflow.com/questions/15935651
- const minInternalImageSize = 16
- if x <= 0 {
- panic("graphics: x must be positive")
- }
- if x < minInternalImageSize {
- return minInternalImageSize
- }
- r := 1
- for r < x {
- r <<= 1
- }
- return r
- }
|