mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-09-20 05:12:18 +02:00
71 lines
2.0 KiB
Go
71 lines
2.0 KiB
Go
// Copyright 2017 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 ebitenutil
|
|
|
|
import (
|
|
"image/color"
|
|
"math"
|
|
|
|
"github.com/hajimehoshi/ebiten"
|
|
)
|
|
|
|
var emptyImage *ebiten.Image
|
|
|
|
func init() {
|
|
emptyImage, _ = ebiten.NewImage(16, 16, ebiten.FilterLinear)
|
|
_ = emptyImage.Fill(color.White)
|
|
}
|
|
|
|
func colorScale(clr color.Color) (rf, gf, bf, af float64) {
|
|
r, g, b, a := clr.RGBA()
|
|
if a == 0 {
|
|
return 0, 0, 0, 0
|
|
}
|
|
|
|
rf = float64(r) / float64(a)
|
|
gf = float64(g) / float64(a)
|
|
bf = float64(b) / float64(a)
|
|
af = float64(a) / 0xffff
|
|
return
|
|
}
|
|
|
|
// DrawLine draws a line on the given destination dst.
|
|
//
|
|
// DrawLine is intended to be used mainly for debugging or prototyping purpose.
|
|
func DrawLine(dst *ebiten.Image, x1, y1, x2, y2 float64, clr color.Color) {
|
|
ew, eh := emptyImage.Size()
|
|
length := math.Hypot(x2-x1, y2-y1)
|
|
|
|
op := &ebiten.DrawImageOptions{}
|
|
op.GeoM.Scale(length/float64(ew), 1/float64(eh))
|
|
op.GeoM.Rotate(math.Atan2(y2-y1, x2-x1))
|
|
op.GeoM.Translate(x1, y1)
|
|
op.ColorM.Scale(colorScale(clr))
|
|
_ = dst.DrawImage(emptyImage, op)
|
|
}
|
|
|
|
// DrawRect draws a rectangle on the given destination dst.
|
|
//
|
|
// DrawRect is intended to be used mainly for debugging or prototyping purpose.
|
|
func DrawRect(dst *ebiten.Image, x, y, width, height float64, clr color.Color) {
|
|
ew, eh := emptyImage.Size()
|
|
|
|
op := &ebiten.DrawImageOptions{}
|
|
op.GeoM.Scale(width/float64(ew), height/float64(eh))
|
|
op.GeoM.Translate(x, y)
|
|
op.ColorM.Scale(colorScale(clr))
|
|
_ = dst.DrawImage(emptyImage, op)
|
|
}
|