Method RenderSetup

graphic/sprite.go:59–94

RenderSetup sets up the rendering of the sprite.

(gs *gls.GLS, rinfo *core.RenderInfo)

// RenderSetup sets up the rendering of the sprite.
func (s *Sprite) RenderSetup(gs *gls.GLS, rinfo *core.RenderInfo) {

	// Calculates model view matrix
	mw := s.MatrixWorld()
	var mvm math32.Matrix4
	mvm.MultiplyMatrices(&rinfo.ViewMatrix, &mw)

	// Decomposes model view matrix
	var position math32.Vector3
	var quaternion math32.Quaternion
	var scale math32.Vector3
	mvm.Decompose(&position, &quaternion, &scale)

	// Removes any rotation in X and Y axes and compose new model view matrix
	rotation := s.Rotation()
	actualScale := s.Scale()
	if actualScale.X >= 0 {
		rotation.Y = 0
	} else {
		rotation.Y = math32.Pi
	}
	if actualScale.Y >= 0 {
		rotation.X = 0
	} else {
		rotation.X = math32.Pi
	}
	quaternion.SetFromEuler(&rotation)
	var mvmNew math32.Matrix4
	mvmNew.Compose(&position, &quaternion, &scale)

	// Calculates final MVP and updates uniform
	var mvpm math32.Matrix4
	mvpm.MultiplyMatrices(&rinfo.ProjMatrix, &mvmNew)
	location := s.uniMVPM.Location(gs)
	gs.UniformMatrix4fv(location, 1, false, &mvpm[0])
}