49 lines
1 KiB
Go
49 lines
1 KiB
Go
package engine
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import (
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"encoding/gob"
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"image"
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"github.com/hajimehoshi/ebiten/v2"
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)
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// Ensure Camera satisfies interfaces.
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var _ interface {
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Identifier
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Prepper
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Transformer
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} = &Camera{}
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func init() {
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gob.Register(&Camera{})
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}
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// Camera models a camera that is viewing a scene. (Camera is a child of the
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// scene it is viewing, for various reasons.) Changes to the fields take effect
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// immediately.
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type Camera struct {
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ID
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// Camera controls
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Centre image.Point // world coordinates
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Filter ebiten.Filter
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Rotation float64 // radians
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Zoom float64 // unitless
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game *Game
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}
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// Prepare grabs a copy of game (needed for screen dimensions)
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func (c *Camera) Prepare(game *Game) error {
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c.game = game
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return nil
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}
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// Transform returns the camera transform.
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func (c *Camera) Transform() (opts ebiten.DrawImageOptions) {
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opts.GeoM.Translate(float2(c.Centre.Mul(-1)))
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opts.GeoM.Scale(c.Zoom, c.Zoom)
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opts.GeoM.Rotate(c.Rotation)
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opts.GeoM.Translate(float64(c.game.ScreenWidth/2), float64(c.game.ScreenHeight/2))
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return opts
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}
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