ebiten/examples/platformer/main.go

161 lines
3.6 KiB
Go
Raw Normal View History

2017-10-28 16:54:42 +02:00
// 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.
// +build example jsgo
2017-10-28 16:54:42 +02:00
package main
import (
"bytes"
2017-10-28 16:54:42 +02:00
"fmt"
"image"
_ "image/png"
2017-10-28 17:06:50 +02:00
2017-10-28 16:54:42 +02:00
"github.com/hajimehoshi/ebiten"
"github.com/hajimehoshi/ebiten/ebitenutil"
rplatformer "github.com/hajimehoshi/ebiten/examples/resources/images/platformer"
"github.com/hajimehoshi/ebiten/inpututil"
2017-10-28 16:54:42 +02:00
)
const (
// Settings
screenWidth = 960
screenHeight = 540
2017-10-28 16:54:42 +02:00
)
var (
leftSprite *ebiten.Image
rightSprite *ebiten.Image
idleSprite *ebiten.Image
backgroundImage *ebiten.Image
2018-01-29 19:57:07 +01:00
)
func init() {
// Preload images
img, _, err := image.Decode(bytes.NewReader(rplatformer.Right_png))
2018-01-29 19:57:07 +01:00
if err != nil {
panic(err)
}
rightSprite, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
img, _, err = image.Decode(bytes.NewReader(rplatformer.Left_png))
2018-01-29 19:57:07 +01:00
if err != nil {
panic(err)
}
leftSprite, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
img, _, err = image.Decode(bytes.NewReader(rplatformer.MainChar_png))
2018-01-29 19:57:07 +01:00
if err != nil {
panic(err)
}
idleSprite, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
img, _, err = image.Decode(bytes.NewReader(rplatformer.Background_png))
2018-01-29 19:57:07 +01:00
if err != nil {
panic(err)
}
backgroundImage, _ = ebiten.NewImageFromImage(img, ebiten.FilterDefault)
2018-01-29 19:57:07 +01:00
}
2017-10-28 16:54:42 +02:00
const (
unit = 16
groundY = 380
2017-10-28 16:54:42 +02:00
)
type char struct {
x int
y int
vx int
vy int
}
func (c *char) tryJump() {
// Now the character can jump anytime, even when the character is not on the ground.
// If you want to restrict the character to jump only when it is on the ground, you can add an 'if' clause:
//
// if gopher.y == groundY * unit {
// ...
gopher.vy = -10 * unit
}
func (c *char) update() {
c.x += c.vx
c.y += c.vy
if c.y > groundY*unit {
c.y = groundY * unit
}
if c.vx > 0 {
c.vx -= 4
} else if c.vx < 0 {
c.vx += 4
}
if c.vy < 20*unit {
c.vy += 8
}
}
func (c *char) draw(screen *ebiten.Image) {
s := idleSprite
switch {
case c.vx > 0:
s = rightSprite
case c.vx < 0:
s = leftSprite
}
op := &ebiten.DrawImageOptions{}
op.GeoM.Scale(0.5, 0.5)
op.GeoM.Translate(float64(c.x)/unit, float64(c.y)/unit)
screen.DrawImage(s, op)
}
var gopher = &char{x: 50 * unit, y: groundY * unit}
2017-10-28 16:54:42 +02:00
func update(screen *ebiten.Image) error {
// Controls
2017-10-28 17:07:26 +02:00
if ebiten.IsKeyPressed(ebiten.KeyA) || ebiten.IsKeyPressed(ebiten.KeyLeft) {
gopher.vx = -4 * unit
2017-10-28 17:07:26 +02:00
} else if ebiten.IsKeyPressed(ebiten.KeyD) || ebiten.IsKeyPressed(ebiten.KeyRight) {
gopher.vx = 4 * unit
2017-10-28 16:54:42 +02:00
}
if inpututil.IsKeyJustPressed(ebiten.KeySpace) {
gopher.tryJump()
}
gopher.update()
2017-10-28 16:54:42 +02:00
if ebiten.IsDrawingSkipped() {
2017-10-28 17:06:50 +02:00
return nil
}
// Draws Background Image
op := &ebiten.DrawImageOptions{}
op.GeoM.Scale(0.5, 0.5)
screen.DrawImage(backgroundImage, op)
// Draws the Gopher
gopher.draw(screen)
2017-10-28 16:54:42 +02:00
// Show the message
msg := fmt.Sprintf("TPS: %0.2f\nPress the space key to jump.", ebiten.CurrentTPS())
ebitenutil.DebugPrint(screen, msg)
2017-10-28 16:54:42 +02:00
return nil
}
func main() {
2018-01-29 19:57:07 +01:00
if err := ebiten.Run(update, screenWidth, screenHeight, 1, "Platformer (Ebiten Demo)"); err != nil {
2017-10-28 16:54:42 +02:00
panic(err)
}
}