mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 04:57:26 +01:00
84 lines
2.6 KiB
Go
84 lines
2.6 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"
|
|
"image/color"
|
|
"math"
|
|
|
|
"github.com/hajimehoshi/ebiten/v2"
|
|
"github.com/hajimehoshi/ebiten/v2/vector"
|
|
)
|
|
|
|
var (
|
|
emptyImage = ebiten.NewImage(3, 3)
|
|
emptySubImage = emptyImage.SubImage(image.Rect(1, 1, 2, 2)).(*ebiten.Image)
|
|
)
|
|
|
|
func init() {
|
|
emptyImage.Fill(color.White)
|
|
}
|
|
|
|
// DrawLine draws a line segment 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) {
|
|
length := math.Hypot(x2-x1, y2-y1)
|
|
|
|
op := &ebiten.DrawImageOptions{}
|
|
op.GeoM.Scale(length, 1)
|
|
op.GeoM.Rotate(math.Atan2(y2-y1, x2-x1))
|
|
op.GeoM.Translate(x1, y1)
|
|
op.ColorM.ScaleWithColor(clr)
|
|
// Filter must be 'nearest' filter (default).
|
|
// Linear filtering would make edges blurred.
|
|
dst.DrawImage(emptySubImage, 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) {
|
|
op := &ebiten.DrawImageOptions{}
|
|
op.GeoM.Scale(width, height)
|
|
op.GeoM.Translate(x, y)
|
|
op.ColorM.ScaleWithColor(clr)
|
|
// Filter must be 'nearest' filter (default).
|
|
// Linear filtering would make edges blurred.
|
|
dst.DrawImage(emptyImage.SubImage(image.Rect(1, 1, 2, 2)).(*ebiten.Image), op)
|
|
}
|
|
|
|
// DrawCircle draws a circle on given destination dst.
|
|
//
|
|
// DrawCircle is intended to be used mainly for debugging or prototyping purpose.
|
|
func DrawCircle(dst *ebiten.Image, cx, cy, r float64, clr color.Color) {
|
|
var path vector.Path
|
|
rd, g, b, a := clr.RGBA()
|
|
|
|
path.Arc(float32(cx), float32(cy), float32(r), 0, 2*math.Pi, vector.Clockwise)
|
|
|
|
vertices, indices := path.AppendVerticesAndIndicesForFilling(nil, nil)
|
|
for i := range vertices {
|
|
vertices[i].SrcX = 1
|
|
vertices[i].SrcY = 1
|
|
vertices[i].ColorR = float32(rd) / 0xffff
|
|
vertices[i].ColorG = float32(g) / 0xffff
|
|
vertices[i].ColorB = float32(b) / 0xffff
|
|
vertices[i].ColorA = float32(a) / 0xffff
|
|
}
|
|
dst.DrawTriangles(vertices, indices, emptySubImage, nil)
|
|
}
|