// toDraw sets the render data needed for a single draw call.
// The data is copied into a render.Draw instance. One of the key jobs
// of this method is to put each draw request into a particular
// render bucket so that they are drawn in order once sorted.
func (sm *scene) toDraw(d render.Draw, p *pov, cam *camera, m *model, rt uint32) {
d.SetMv(sm.mv.Mult(p.mm, cam.vm)) // model-view
d.SetMvp(sm.mvp.Mult(sm.mv, cam.pm)) // model-view-projection
d.SetPm(cam.pm) // projection only.
d.SetScale(p.Scale())
d.SetTag(p.eid)
// Set the drawing order hints. Overlay trumps transparency since 2D overlay
// objects can't be sorted by distance anyways.
bucket := render.OPAQUE // used to sort the draw data. Lowest first.
switch {
case m.castShadow && rt > 0:
bucket = render.DEPTH_PASS // pre-passes first.
case cam.overlay > 0:
bucket = cam.overlay // OVERLAY draw last.
case m.alpha < 1:
bucket = render.TRANSPARENT // sort and draw after opaque.
}
depth := cam.depth && m.depth // both must be true for depth rendering.
tocam := 0.0
if depth {
tocam = p.toc
}
d.SetHints(bucket, tocam, depth, rt)
// use the shadow map texture for models that show shadows.
if m.hasShadows {
m.UseLayer(sm.shadowMap)
}
}
// toDraw sets all the data references and uniform data needed
// by the rendering layer.
func (m *model) toDraw(d render.Draw, eid uint64, depth bool, overlay int, distToCam float64) {
d.SetTag(eid)
d.SetAlpha(float64(m.alpha)) // 1 : no transparency as the default.
// Set the drawing hints. Overlay trumps transparency since 2D overlay
// objects can't be sorted by distance anyways.
bucket := OPAQUE // used to sort the draw data. Lowest first.
switch {
case overlay > 0:
bucket = overlay // OVERLAY draw last.
case m.alpha < 1:
bucket = TRANSPARENT // sort and draw after opaque.
}
depth = depth && m.depth // both must be true for depth rendering.
tocam := 0.0
if depth {
tocam = distToCam
}
d.SetHints(bucket, tocam, depth)
// Set the drawing references.
d.SetRefs(m.shd.program, m.msh.vao, m.drawMode)
if total := len(m.texs); total > 0 {
for cnt, t := range m.texs {
d.SetTex(total, cnt, t.tid, t.f0, t.fn)
}
} else {
d.SetTex(0, 0, 0, 0, 0) // clear any previous data.
}
// Set uniform values. These can be sent as a reference because they
// are fixed on shader creation.
d.SetUniforms(m.shd.uniforms) // shader integer uniform references.
if m.anm != nil && len(m.pose) > 0 {
d.SetPose(m.pose)
} else {
d.SetPose(nil) // clear data.
}
d.SetTime(time.Since(m.time).Seconds()) // For shaders that need elapsed time.
// Set colour uniforms.
d.SetFloats("kd", m.kd.R, m.kd.G, m.kd.B)
d.SetFloats("ks", m.ks.R, m.ks.G, m.ks.B)
d.SetFloats("ka", m.ka.R, m.ka.G, m.ka.B)
// Set user specificed uniforms.
for uniform, uvalues := range m.uniforms {
d.SetFloats(uniform, uvalues...)
}
}