52 lines
1.1 KiB
Go
52 lines
1.1 KiB
Go
package gg
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// Implements the camera component
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// for the main window.
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type Camera struct {
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// The shaders that will be applied to everything
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// that the camera shows.
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ShaderOptions
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Transform
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buffered bool
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buf Matrix
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engine *Engine
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}
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func (e *Engine) NewCamera() *Camera {
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ret := &Camera{}
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ret.Transform = T()
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ret.engine = e
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return ret
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}
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// Returns the matrix satysfying camera
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// position, scale and rotation to apply
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// it to the objects to get the real
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// transform to display on the screen.
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func (c *Camera)RealMatrix() Matrix {
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// Bufferization
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if c.buffered {
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return c.buf
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}
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g := Matrix{}
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g.Translate(-c.Position.X, -c.Position.Y)
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g.Rotate(c.Rotation)
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siz := c.engine.AbsWinSize()
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g.Translate(c.Around.X * siz.X, c.Around.Y * siz.Y)
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g.Scale(c.Scale.X, c.Scale.Y)
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c.buf = g
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c.buffered = true
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return g
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}
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// The matrix to convert things into the
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// inside engine representation,
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// get the position of cursor inside the world
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// basing on its window position.
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func (c *Camera) AbsMatrix() Matrix {
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m := c.RealMatrix()
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m.Invert()
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return m
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}
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