mth/ebiten
1
0
Fork 0
mirror of https://github.com/hajimehoshi/ebiten.git synced 2024-12-24 18:58:54 +01:00
Code Issues Packages Projects Releases Wiki Activity

examples/shapes: Use DrawTriangles (#680)

Browse Source
This commit is contained in:
Hajime Hoshi 2018-09-15 17:20:35 +09:00
parent aae79e39ab
commit 5587af9d7e
1 changed files with 71 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
examples/shapes/main.go
View File

@ -20,6 +20,7 @@ import (
"fmt"
"image/color"
"log"
"math"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
@ -30,8 +31,72 @@ const (
screenHeight = 480
)
var (
emptyImage, _ = ebiten.NewImage(16, 16, ebiten.FilterDefault)
)
func init() {
emptyImage.Fill(color.White)
}
var count = 0
func line(x0, y0, x1, y1 float32, clr color.RGBA) ([]ebiten.Vertex, []uint16) {
const width = 0.5
theta := math.Atan2(float64(x1-x0), float64(y1-y0))
dx := float32(math.Cos(theta) - math.Sin(theta))
dy := float32(math.Sin(theta) + math.Cos(theta))
r := float32(clr.R) / 0xff
g := float32(clr.G) / 0xff
b := float32(clr.B) / 0xff
a := float32(clr.A) / 0xff
return []ebiten.Vertex{
{
DstX: x0 - width*dx,
DstY: y0 - width*dy,
SrcX: 1,
SrcY: 1,
ColorR: r,
ColorG: g,
ColorB: b,
ColorA: a,
},
{
DstX: x0 + width*dx,
DstY: y0 + width*dy,
SrcX: 1,
SrcY: 1,
ColorR: r,
ColorG: g,
ColorB: b,
ColorA: a,
},
{
DstX: x1 - width*dx,
DstY: y1 - width*dy,
SrcX: 1,
SrcY: 1,
ColorR: r,
ColorG: g,
ColorB: b,
ColorA: a,
},
{
DstX: x1 + width*dx,
DstY: y1 + width*dy,
SrcX: 1,
SrcY: 1,
ColorR: r,
ColorG: g,
ColorB: b,
ColorA: a,
},
}, []uint16{0, 1, 2, 1, 2, 3}
}
func update(screen *ebiten.Image) error {
count++
count %= 240
@ -41,9 +106,12 @@ func update(screen *ebiten.Image) error {
}
cf := float64(count)
ebitenutil.DrawLine(screen, 100, 100, 300, 100, color.RGBA{0xff, 0, 0xff, 0xff})
ebitenutil.DrawLine(screen, 50, 150, 50, 350, color.RGBA{0xff, 0xff, 0, 0xff})
ebitenutil.DrawLine(screen, 50, 100+cf, 200+cf, 250, color.RGBA{0x00, 0xff, 0xff, 0xff})
v, i := line(100, 100, 300, 100, color.RGBA{0xff, 0xff, 0xff, 0xff})
screen.DrawTriangles(v, i, emptyImage, nil)
v, i = line(50, 150, 50, 350, color.RGBA{0xff, 0xff, 0xff, 0xff})
screen.DrawTriangles(v, i, emptyImage, nil)
v, i = line(50, 100+float32(cf), 200+float32(cf), 250, color.RGBA{0x00, 0xff, 0xff, 0xff})
screen.DrawTriangles(v, i, emptyImage, nil)
ebitenutil.DrawRect(screen, 50+cf, 50+cf, 100+cf, 100+cf, color.RGBA{0x80, 0x80, 0x80, 0x80})
ebitenutil.DrawRect(screen, 300-cf, 50, 120, 120, color.RGBA{0x00, 0x80, 0x00, 0x80})