func (r *RenderTarget) pushGlStates() {
gl.PushClientAttrib(gl.CLIENT_ALL_ATTRIB_BITS)
gl.PushAttrib(gl.ALL_ATTRIB_BITS)
gl.MatrixMode(gl.MODELVIEW)
gl.PushMatrix()
gl.MatrixMode(gl.PROJECTION)
gl.PushMatrix()
gl.MatrixMode(gl.TEXTURE)
gl.PushMatrix()
r.resetGlStates()
}
// Arrays mode uses vertex arrays which involves gl*Pointer calls and
// directly passing in the vertex data on every render pass. This is slower
// than using VBO's, because the data has to be uploaded to the GPU on every
// render pass, but it is useful for older systems where glBufferData is
// not available.
func (mb *MeshBuffer) renderArrays(mode gl.GLenum, m Mesh, pa, ca, na, ta, ia *Attr) {
ps, pc := m[mbPositionKey][0], m[mbPositionKey][1]
is, ic := m[mbIndexKey][0], m[mbIndexKey][1]
cc := m[mbColorKey][1]
nc := m[mbNormalKey][1]
tc := m[mbTexCoordKey][1]
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
defer gl.PopClientAttrib()
if pc > 0 {
gl.EnableClientState(gl.VERTEX_ARRAY)
defer gl.DisableClientState(gl.VERTEX_ARRAY)
gl.VertexPointer(pa.size, pa.typ, 0, pa.ptr(0))
}
if cc > 0 {
gl.EnableClientState(gl.COLOR_ARRAY)
defer gl.DisableClientState(gl.COLOR_ARRAY)
gl.ColorPointer(ca.size, ca.typ, 0, ca.ptr(0))
}
if nc > 0 {
gl.EnableClientState(gl.NORMAL_ARRAY)
defer gl.DisableClientState(gl.NORMAL_ARRAY)
gl.NormalPointer(na.typ, 0, na.ptr(0))
}
if tc > 0 {
gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
defer gl.DisableClientState(gl.TEXTURE_COORD_ARRAY)
gl.TexCoordPointer(ta.size, ta.typ, 0, ta.ptr(0))
}
if ic > 0 {
gl.EnableClientState(gl.INDEX_ARRAY)
defer gl.DisableClientState(gl.INDEX_ARRAY)
gl.IndexPointer(ia.typ, 0, ia.ptr(0))
gl.DrawElements(mode, ic, ia.typ, ia.ptr(is*ia.size))
} else {
gl.DrawArrays(mode, ps, pc)
}
}
// renderBuffered uses VBO's. This is the preferred mode for systems
// where shader support is not present or deemed necessary.
func (mb *MeshBuffer) renderBuffered(mode gl.GLenum, m Mesh, pa, ca, na, ta, ia *Attr) {
ps, pc := m[mbPositionKey][0], m[mbPositionKey][1]
is, ic := m[mbIndexKey][0], m[mbIndexKey][1]
cc := m[mbColorKey][1]
nc := m[mbNormalKey][1]
tc := m[mbTexCoordKey][1]
if pc > 0 {
gl.EnableClientState(gl.VERTEX_ARRAY)
defer gl.DisableClientState(gl.VERTEX_ARRAY)
pa.bind()
if pa.Invalid() {
pa.buffer()
}
gl.VertexPointer(pa.size, pa.typ, 0, uintptr(0))
pa.unbind()
}
if cc > 0 {
gl.EnableClientState(gl.COLOR_ARRAY)
defer gl.DisableClientState(gl.COLOR_ARRAY)
ca.bind()
if ca.Invalid() {
ca.buffer()
}
gl.ColorPointer(ca.size, ca.typ, 0, uintptr(0))
ca.unbind()
}
if nc > 0 {
gl.EnableClientState(gl.NORMAL_ARRAY)
defer gl.DisableClientState(gl.NORMAL_ARRAY)
na.bind()
if na.Invalid() {
na.buffer()
}
gl.NormalPointer(na.typ, 0, uintptr(0))
na.unbind()
}
if tc > 0 {
gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
defer gl.DisableClientState(gl.TEXTURE_COORD_ARRAY)
ta.bind()
if ta.Invalid() {
ta.buffer()
}
gl.TexCoordPointer(ta.size, ta.typ, 0, uintptr(0))
ta.unbind()
}
if ic > 0 {
ia.bind()
if ia.Invalid() {
ia.buffer()
}
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
gl.DrawElements(mode, ic, ia.typ, uintptr(is*ia.stride))
gl.PopClientAttrib()
ia.unbind()
} else {
pa.bind()
gl.PushClientAttrib(gl.CLIENT_VERTEX_ARRAY_BIT)
gl.DrawArrays(mode, ps, pc)
gl.PopClientAttrib()
pa.unbind()
}
}