ebiten/example/game/rects/rects.go
2013-10-12 22:33:55 +09:00

100 lines
2.6 KiB
Go

package rects
import (
"github.com/hajimehoshi/go.ebiten"
"github.com/hajimehoshi/go.ebiten/graphics"
"github.com/hajimehoshi/go.ebiten/graphics/matrix"
"image/color"
"math"
"math/rand"
"time"
)
type Rects struct {
rectTexture graphics.RenderTarget
rectTextureInited bool
offscreen graphics.RenderTarget
offscreenInited bool
rectBounds *graphics.Rect
rectColor *color.RGBA
}
func New() *Rects {
return &Rects{
rectTextureInited: false,
offscreenInited: false,
rectBounds: &graphics.Rect{},
rectColor: &color.RGBA{},
}
}
func (game *Rects) Init(tf graphics.TextureFactory) {
game.rectTexture = tf.NewRenderTarget(16, 16)
game.offscreen = tf.NewRenderTarget(256, 240)
}
func (game *Rects) Update(context ebiten.GameContext) {
game.rectBounds.X = rand.Intn(context.ScreenWidth())
game.rectBounds.Y = rand.Intn(context.ScreenHeight())
game.rectBounds.Width =
rand.Intn(context.ScreenWidth() - game.rectBounds.X)
game.rectBounds.Height =
rand.Intn(context.ScreenHeight() - game.rectBounds.Y)
game.rectColor.R = uint8(rand.Intn(256))
game.rectColor.G = uint8(rand.Intn(256))
game.rectColor.B = uint8(rand.Intn(256))
game.rectColor.A = uint8(rand.Intn(256))
}
func (game *Rects) rectGeometryMatrix() matrix.Geometry {
geometryMatrix := matrix.IdentityGeometry()
scaleX := float64(game.rectBounds.Width) /
float64(game.rectTexture.Width())
scaleY := float64(game.rectBounds.Height) /
float64(game.rectTexture.Height())
geometryMatrix.Scale(scaleX, scaleY)
geometryMatrix.Translate(
float64(game.rectBounds.X), float64(game.rectBounds.Y))
return geometryMatrix
}
func (game *Rects) rectColorMatrix() matrix.Color {
colorMatrix := matrix.IdentityColor()
colorMatrix.Elements[0][0] =
float64(game.rectColor.R) / float64(math.MaxUint8)
colorMatrix.Elements[1][1] =
float64(game.rectColor.G) / float64(math.MaxUint8)
colorMatrix.Elements[2][2] =
float64(game.rectColor.B) / float64(math.MaxUint8)
colorMatrix.Elements[3][3] =
float64(game.rectColor.A) / float64(math.MaxUint8)
return colorMatrix
}
func (game *Rects) Draw(g graphics.Context) {
if !game.rectTextureInited {
g.SetOffscreen(game.rectTexture.ID())
g.Fill(255, 255, 255)
game.rectTextureInited = true
}
g.SetOffscreen(game.offscreen.ID())
if !game.offscreenInited {
g.Fill(0, 0, 0)
game.offscreenInited = true
}
g.DrawTexture(game.rectTexture.Texture().ID(),
game.rectGeometryMatrix(),
game.rectColorMatrix())
g.SetOffscreen(g.Screen().ID())
g.DrawTexture(game.offscreen.Texture().ID(),
matrix.IdentityGeometry(),
matrix.IdentityColor())
}
func init() {
rand.Seed(time.Now().UnixNano())
}