ebiten/examples/spriteshd/main.go

197 lines
4.7 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.
// +build example jsgo
package main
import (
"bytes"
"errors"
"fmt"
"image"
_ "image/png"
"log"
"math"
"math/rand"
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
"github.com/hajimehoshi/ebiten/examples/resources/images"
"github.com/hajimehoshi/ebiten/inpututil"
)
const (
screenWidth = 1920
screenHeight = 1080
maxAngle = 256
)
var (
ebitenImage *ebiten.Image
)
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
)
var (
sprites = &Sprites{make([]*Sprite, MaxSprites), 500}
op = &ebiten.DrawImageOptions{}
)
func init() {
// Decode image from a byte slice instead of a file so that
// this example works in any working directory.
// If you want to use a file, there are some options:
// 1) Use os.Open and pass the file to the image decoder.
// This is a very regular way, but doesn't work on browsers.
// 2) Use ebitenutil.OpenFile and pass the file to the image decoder.
// This works even on browsers.
// 3) Use ebitenutil.NewImageFromFile to create an ebiten.Image directly from a file.
// This also works on browsers.
img, _, err := image.Decode(bytes.NewReader(images.Ebiten_png))
if err != nil {
log.Fatal(err)
}
origEbitenImage, _ := ebiten.NewImageFromImage(img, ebiten.FilterDefault)
w, h := origEbitenImage.Size()
ebitenImage, _ = ebiten.NewImage(w, h, ebiten.FilterDefault)
op := &ebiten.DrawImageOptions{}
op.ColorM.Scale(1, 1, 1, 0.5)
ebitenImage.DrawImage(origEbitenImage, op)
for i := range 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)
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 update(screen *ebiten.Image) error {
if inpututil.IsKeyJustPressed(ebiten.KeyQ) {
return regularTermination
}
// Decrease the nubmer of the sprites.
if ebiten.IsKeyPressed(ebiten.KeyLeft) {
sprites.num -= 20
if sprites.num < MinSprites {
sprites.num = MinSprites
}
}
// Increase the nubmer of the sprites.
if ebiten.IsKeyPressed(ebiten.KeyRight) {
sprites.num += 20
if MaxSprites < sprites.num {
sprites.num = MaxSprites
}
}
sprites.Update()
if ebiten.IsDrawingSkipped() {
return nil
}
// 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#Image.DrawImage
w, h := ebitenImage.Size()
for i := 0; i < sprites.num; i++ {
s := sprites.sprites[i]
op.GeoM.Reset()
op.GeoM.Translate(-float64(w)/2, -float64(h)/2)
op.GeoM.Rotate(2 * math.Pi * float64(s.angle) / maxAngle)
op.GeoM.Translate(float64(w)/2, float64(h)/2)
op.GeoM.Translate(float64(s.x), float64(s.y))
screen.DrawImage(ebitenImage, 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(), sprites.num)
ebitenutil.DebugPrint(screen, msg)
return nil
}
func main() {
ebiten.SetFullscreen(true)
if err := ebiten.Run(update, screenWidth, screenHeight, 1, "Sprites HD (Ebiten Demo)"); err != nil && err != regularTermination {
log.Fatal(err)
}
}