func bufferSetUp(buffer bufferSetUpInt, program gl.Program) {
buffer.gen()
buffer.bind()
// Collect the attrib locations for each attrib name.
atts_names := buffer.names() // Expected GLSL variable names.
atts := make([]gl.AttribLocation, len(atts_names))
for i, att_name := range atts_names {
atts[i] = program.GetAttribLocation(att_name)
if err := CheckGlError(); err != nil {
err.Description = fmt.Sprintf("program.GetAttribLocation(%#v)", att_name)
panic(err)
}
if atts[i] == -1 {
panic(fmt.Sprintf("attrib location %#v not found", att_name))
}
}
// Now that the locations are known, we can relate them to vertex data.
buffer.attribPointers(atts)
buffer.unbind()
}
// 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, program gl.Program) {
is, ic := m[mbIndexKey][0], m[mbIndexKey][1]
program.Use()
var attribLocation gl.AttribLocation
for _, value := range mb.attr {
if value.name == "index" {
continue
}
value.bind()
if value.Invalid() {
value.buffer()
}
attribLocation = program.GetAttribLocation(value.name)
attribLocation.EnableArray()
attribLocation.AttribPointer(value.size, value.typ, false, 0, uintptr(0))
value.unbind()
}
ia := mb.find(mbIndexKey)
ia.bind()
if ia.Invalid() {
ia.buffer()
}
gl.DrawElements(mode, ic, ia.typ, uintptr(is*ia.stride))
ia.unbind()
for _, value := range mb.attr {
if value.name == "index" {
continue
}
attribLocation := program.GetAttribLocation(value.name)
attribLocation.DisableArray()
}
}