ebiten/examples/spriteshd/main.go

209 lines
4.8 KiB
Go

// Copyright 2018 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.
//go:build example
// +build example
package main
import (
"bytes"
"errors"
"fmt"
"image"
_ "image/png"
"log"
"math"
"math/rand"
"github.com/hajimehoshi/ebiten/v2"
"github.com/hajimehoshi/ebiten/v2/ebitenutil"
"github.com/hajimehoshi/ebiten/v2/examples/resources/images"
"github.com/hajimehoshi/ebiten/v2/inpututil"
)
const (
screenWidth = 1920
screenHeight = 1080
maxAngle = 256
)
var (
ebitenImage *ebiten.Image
)
func init() {
// Decode an image from the image file's byte slice.
// Now the byte slice is generated with //go:generate for Go 1.15 or older.
// If you use Go 1.16 or newer, it is strongly recommended to use //go:embed to embed the image file.
// See https://pkg.go.dev/embed for more details.
img, _, err := image.Decode(bytes.NewReader(images.Ebiten_png))
if err != nil {
log.Fatal(err)
}
origEbitenImage := ebiten.NewImageFromImage(img)
w, h := origEbitenImage.Size()
ebitenImage = ebiten.NewImage(w, h)
op := &ebiten.DrawImageOptions{}
op.ColorM.Scale(1, 1, 1, 0.5)
ebitenImage.DrawImage(origEbitenImage, op)
}
type Sprite struct {
imageWidth int
imageHeight int
x int
y int
vx int
vy int
angle int
}
func (s *Sprite) Update() {
s.x += s.vx
s.y += s.vy
if s.x < 0 {
s.x = -s.x
s.vx = -s.vx
} else if screenWidth <= s.x+s.imageWidth {
s.x = 2*(screenWidth-s.imageWidth) - s.x
s.vx = -s.vx
}
if s.y < 0 {
s.y = -s.y
s.vy = -s.vy
} else if screenHeight <= s.y+s.imageHeight {
s.y = 2*(screenHeight-s.imageHeight) - s.y
s.vy = -s.vy
}
s.angle++
s.angle %= maxAngle
}
type Sprites struct {
sprites []*Sprite
num int
}
func (s *Sprites) Update() {
for _, sprite := range s.sprites {
sprite.Update()
}
}
const (
MinSprites = 0
MaxSprites = 50000
)
type Game struct {
sprites Sprites
op ebiten.DrawImageOptions
inited bool
}
func (g *Game) init() {
defer func() {
g.inited = true
}()
g.sprites.sprites = make([]*Sprite, MaxSprites)
g.sprites.num = 500
for i := range g.sprites.sprites {
w, h := ebitenImage.Size()
x, y := rand.Intn(screenWidth-w), rand.Intn(screenHeight-h)
vx, vy := 2*rand.Intn(2)-1, 2*rand.Intn(2)-1
a := rand.Intn(maxAngle)
g.sprites.sprites[i] = &Sprite{
imageWidth: w,
imageHeight: h,
x: x,
y: y,
vx: vx,
vy: vy,
angle: a,
}
}
}
var regularTermination = errors.New("regular termination")
func (g *Game) Update() error {
if !g.inited {
g.init()
}
if inpututil.IsKeyJustPressed(ebiten.KeyQ) {
return regularTermination
}
// Decrease the number of the sprites.
if ebiten.IsKeyPressed(ebiten.KeyArrowLeft) {
g.sprites.num -= 20
if g.sprites.num < MinSprites {
g.sprites.num = MinSprites
}
}
// Increase the number of the sprites.
if ebiten.IsKeyPressed(ebiten.KeyArrowRight) {
g.sprites.num += 20
if MaxSprites < g.sprites.num {
g.sprites.num = MaxSprites
}
}
g.sprites.Update()
return nil
}
func (g *Game) Draw(screen *ebiten.Image) {
// Draw each sprite.
// DrawImage can be called many many times, but in the implementation,
// the actual draw call to GPU is very few since these calls satisfy
// some conditions e.g. all the rendering sources and targets are same.
// For more detail, see:
// https://pkg.go.dev/github.com/hajimehoshi/ebiten/v2#Image.DrawImage
w, h := ebitenImage.Size()
for i := 0; i < g.sprites.num; i++ {
s := g.sprites.sprites[i]
g.op.GeoM.Reset()
g.op.GeoM.Translate(-float64(w)/2, -float64(h)/2)
g.op.GeoM.Rotate(2 * math.Pi * float64(s.angle) / maxAngle)
g.op.GeoM.Translate(float64(w)/2, float64(h)/2)
g.op.GeoM.Translate(float64(s.x), float64(s.y))
screen.DrawImage(ebitenImage, &g.op)
}
msg := fmt.Sprintf(`TPS: %0.2f
FPS: %0.2f
Num of sprites: %d
Press <- or -> to change the number of sprites
Press Q to quit`, ebiten.CurrentTPS(), ebiten.CurrentFPS(), g.sprites.num)
ebitenutil.DebugPrint(screen, msg)
}
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
return screenWidth, screenHeight
}
func main() {
ebiten.SetFullscreen(true)
ebiten.SetWindowTitle("Sprites HD (Ebiten Demo)")
if err := ebiten.RunGame(&Game{}); err != nil && err != regularTermination {
log.Fatal(err)
}
}