// Check that the inverse of a perspective view is correct.
func TestInverseVp(t *testing.T) {
v := newCamera()
v.at.Loc.SetS(10, 10, 10)
v.at.Rot.SetAa(1, 0, 0, -lin.Rad(90))
vm := VP(v.at, lin.NewQ(), &lin.M4{})
ivm := ivp(v.at, &lin.Q{X: 1, Y: 0, Z: 0, W: 1}, lin.NewQ(), &lin.M4{})
if !vm.Mult(vm, ivm).Aeq(lin.M4I) {
t.Errorf("Matrix times inverse should be identity")
}
}
// newCamera creates a default point of view that is looking down
// the positive Z axis.
func newCamera() *camera {
c := &camera{depth: true}
c.vt = VP
c.at = lin.NewT()
c.vm = &lin.M4{}
c.ivm = (&lin.M4{}).Set(lin.M4I)
c.pm = &lin.M4{}
c.ipm = &lin.M4{}
c.q0 = &lin.Q{}
c.xrot = lin.NewQ().SetAa(1, 0, 0, 0)
c.yrot = lin.NewQ().SetAa(0, 1, 0, 0)
c.v0 = &lin.V4{}
c.ray = &lin.V3{}
return c
}
// drawScene renders the 3D models consisting of one VAO
func (tag *trtag) drawScene() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
tag.checkError("gl.Clear")
gl.UseProgram(tag.shaders)
tag.checkError("gl.UseProgram")
gl.BindVertexArray(tag.vao)
tag.checkError("gl.BindVertexArray")
// Use a modelview matrix and quaternion to rotate the 3D object.
tag.mvp64.SetQ(lin.NewQ().SetAa(0, 1, 0, lin.Rad(-tag.rotateAngle)))
tag.mvp64.TranslateMT(0, 0, -4)
tag.mvp.Set(tag.mvp64.Mult(tag.mvp64, tag.persp))
gl.UniformMatrix4fv(tag.mvpRef, 1, false, tag.mvp.Pointer())
if err := gl.GetError(); err != 0 {
fmt.Printf("gl.UniformMatrix error %d\n", err)
}
gl.DrawElements(gl.TRIANGLES, int32(len(tag.faces)), gl.UNSIGNED_BYTE, 0)
if err := gl.GetError(); err != 0 {
fmt.Printf("gl.DrawElements error %d\n", err)
}
// cleanup
gl.UseProgram(0)
tag.checkError("gl.UseProgram-0")
gl.BindVertexArray(0)
tag.checkError("gl.BindVertexArray-0")
// rotate based on time... not on how fast the computer runs.
if time.Now().Sub(tag.lastTime).Seconds() > 0.01 {
tag.rotateAngle += 1
tag.lastTime = time.Now()
}
}
// newPov allocates and initialzes a point of view transform.
func newPov(eng *engine, eid uint64) *pov {
p := &pov{eng: eng, eid: eid, visible: true}
p.at = lin.NewT()
p.scale = &lin.V3{X: 1, Y: 1, Z: 1}
// allocate scratch variables.
p.rot = lin.NewQ()
p.mm = &lin.M4{}
return p
}