/*
	This file is part of Reindeer-OpenGL.

	Copyright (C) 2008, 2009, 2010 - Patrik Olsson

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "opengl.h"
#include "conversion.h"

static inline ren_bool
coord_array_bind (RenReindeer *r, RenVectorArray *array);

ren_bool
REN_IMPL_MANGLE(coord_array_bind) (RenReindeer *r, RenVectorArray *array)
{
	RenReindeerBackData *r_bd = ren_reindeer_back_data (r);
	if (r_bd->curr_coord_array != array)
	{
		if (array == NULL)
		{
			r_bd->prev_coord_array = r_bd->curr_coord_array;
			glDisableClientState (GL_VERTEX_ARRAY);
		}
		else
		{
			if (r_bd->curr_coord_array != NULL ||
				array != r_bd->prev_coord_array)
			{
				if (!coord_array_bind (r, array))
					return FALSE;
				if (r_bd->curr_coord_array == NULL)
					glEnableClientState (GL_VERTEX_ARRAY);
			}
			else
			{
				glEnableClientState (GL_VERTEX_ARRAY);
			}
		}
		r_bd->curr_coord_array = array;
	}
	return TRUE;
}

static inline ren_bool
coord_array_bind (RenReindeer *r, RenVectorArray *array)
{
	RenType type;
	ren_uint08 num;
	ren_vector_array_type (array, &type, &num);
	GLenum gl_type = convert_ren_type_to_gl_type (type);
	if (gl_type == -1)
		return FALSE;

	RenDataBlock *datablock;
	ren_size start;
	ren_size count;
	ren_size stride;
	ren_vector_array_data (array, &datablock, &start, &count, &stride);

	const void *data = ren_data_block_info (datablock)->data;

	if (num > 4)
		num = 4;
	if (type == REN_TYPE_SINT08)
		return FALSE;
	/* FIXME: The signed byte type is not actually valid for
	VertexPointer, in that case we might need to convert. That could
	however be done by the main library since it's common enough that
	many backends will want to use such converted data. Unsigned types
	are not either supported, but I think that will apply for Reindeer
	as well. */
	glVertexPointer (num, gl_type, stride, data + start);
	return TRUE;
}