// Move moves the Shape object a specified distance.
func (shape *Shape) Move(x, y float64) {
var verticies []float32
for i := 0; i < len(shape.verticies); i += 2 {
shape.verticies[i] += float32(x)
shape.verticies[i+1] += float32(y)
}
if shape.scaleX != 1 || shape.scaleY != 1 {
verticies = make([]float32, len(shape.verticies))
xTransform := shape.verticies[0] - (shape.verticies[0] * float32(shape.scaleX))
yTransform := shape.verticies[1] - (shape.verticies[1] * float32(shape.scaleY))
for i := range verticies {
if i%2 == 0 {
verticies[i] = shape.verticies[i] * float32(shape.scaleX)
verticies[i] += xTransform
} else {
verticies[i] = shape.verticies[i] * float32(shape.scaleY)
verticies[i] += yTransform
}
}
} else {
verticies = shape.verticies
}
gl.BindBuffer(gl.ARRAY_BUFFER, shape.vertexBuffer)
gl.BufferSubData(gl.ARRAY_BUFFER, 0, gl.Sizeiptr(len(verticies)*4), gl.Pointer(&verticies[0]))
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
// SetScaling sets the scaling factor of the Shape object. For instance, an x
// and y scale value of two will make the Shape object twice as large.
func (shape *Shape) SetScaling(scaleX, scaleY float64) {
shape.scaleX = scaleX
shape.scaleY = scaleY
verticies := make([]float32, len(shape.verticies))
xTransform := shape.verticies[0] - (shape.verticies[0] * float32(scaleX))
yTransform := shape.verticies[1] - (shape.verticies[1] * float32(scaleY))
for i := range verticies {
if i%2 == 0 {
verticies[i] = shape.verticies[i] * float32(scaleX)
verticies[i] += xTransform
} else {
verticies[i] = shape.verticies[i] * float32(scaleY)
verticies[i] += yTransform
}
}
gl.BindBuffer(gl.ARRAY_BUFFER, shape.vertexBuffer)
gl.BufferSubData(gl.ARRAY_BUFFER, 0, gl.Sizeiptr(len(verticies)*4), gl.Pointer(&verticies[0]))
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}