/* $Id$

This file is part of libmspgl
Copyright © 2010  Mikko Rasa, Mikkosoft Productions
Distributed under the LGPL
*/

#include <msp/core/getopt.h>
#include <msp/gl/mesh.h>
#include <msp/io/print.h>
#include <msp/strings/formatter.h>

using namespace std;
using namespace Msp;

const char *types[] =
{
	"unsigned char", "GL_UNSIGNED_BYTE",
	"unsigned short", "GL_UNSIGNED_SHORT",
	"unsigned", "GL_UNSIGNED_INT"
};

int main(int argc, char **argv)
{
	string prefix;
	bool render_func = false;
	bool separate_arrays = false;
	GetOpt getopt;
	getopt.add_option('p', "prefix",      prefix,      GetOpt::REQUIRED_ARG);
	getopt.add_option('r', "render-func", render_func, GetOpt::NO_ARG);
	getopt.add_option('s', "separate-arrays", separate_arrays, GetOpt::NO_ARG);
	getopt(argc, argv);

	const vector<string> &args = getopt.get_args();
	if(args.empty())
	{
		IO::print(IO::cerr, "Usage: %s [options] <meshfile>\n", argv[0]);
		return 1;
	}

	GL::Mesh mesh;
	mesh.use_buffers(false);
	DataFile::load(mesh, args[0]);

	IO::print("/* Exported from %s */\n", args[0]);

	const GL::VertexArray &array = mesh.get_vertices();
	const GL::VertexFormat &fmt = array.get_format();
	unsigned stride = fmt.stride();
	if(separate_arrays)
	{
		unsigned offset = 0;
		for(const unsigned char *i=fmt.begin(); i!=fmt.end(); ++i)
		{
			unsigned kind = (*i)>>2;
			unsigned size = ((*i)&3)+1;
			string name;
			switch(kind)
			{
			case 0:
				name = "vertex";
				break;
			case 1:
				name = "normal";
				break;
			case 2:
				name = "color";
				break;
			case 3:
				name = "texcoord";
				break;
			default:
				if(kind<11)
					name = format("texcoord%d", kind-3);
				else
					name = format("attrib%d", kind-11);
				break;
			}

			IO::print("float %s%s_data[] =\n{", prefix, name);
			for(unsigned j=0; j<array.size(); ++j)
			{
				const float *ptr = array[j]+offset;
				IO::print("\n\t");
				for(unsigned k=0; k<size; ++k)
					IO::print("%g, ", ptr[k]);
			}
			IO::print("\n};\n\n");

			offset += size;
		}
	}
	else
	{
		IO::print("float %svertex_data[] =\n{", prefix);
		for(unsigned i=0; i<array.size(); ++i)
		{
			const float *ptr = array[i];
			IO::print("\n\t");
			for(unsigned j=0; j<stride; ++j)
				IO::print("%g, ", ptr[j]);
		}
		IO::print("\n};\n\n");
	}

	const char **type = 0;
	if(array.size()<0x100)
		type = types;
	else if(array.size()<0x10000)
		type = types+2;
	else
		type = types+4;

	IO::print("%s %sindices[] =\n{", type[0], prefix);
	for(list<GL::Batch>::const_iterator i=mesh.get_batches().begin(); i!=mesh.get_batches().end(); ++i)
	{
		unsigned count = i->size();
		for(unsigned j=0; j<count; ++j)
		{
			if(j%16==0)
				IO::print("\n\t");
			IO::print("%d, ", i->get_index(j));
		}
	}
	IO::print("\n};\n\n");

	if(render_func)
		IO::print("void %srender()\n{\n", prefix);
	else
		IO::print("/*\nTo render the object, #include this file and add the following code:\n");
	unsigned offset = 0;
	for(const unsigned char *i=fmt.begin(); i!=fmt.end(); ++i)
	{
		unsigned kind = (*i)>>2;
		unsigned size = ((*i)&3)+1;
		string source = format("%svertex_data+%d", prefix, offset);
		switch((*i)>>2)
		{
		case 0:
			if(separate_arrays)
				source = prefix+"vertex_data";
			IO::print("\tglVertexPointer(%d, GL_FLOAT, %d*sizeof(float), %s);\n",
				size, stride, source);
			IO::print("\tglEnableClientState(GL_VERTEX_ARRAY);\n");
			break;
		case 1:
			if(separate_arrays)
				source = prefix+"normal_data";
			IO::print("\tglNormalPointer(GL_FLOAT, %d*sizeof(float), %s);\n",
				stride, source);
			IO::print("\tglEnableClientState(GL_NORMAL_ARRAY);\n");
			break;
		case 2:
			if(separate_arrays)
				source = prefix+"color_data";
			IO::print("\tglColorPointer(%d, GL_FLOAT, %d*sizeof(float), %s);\n",
				size, stride, source);
			IO::print("\tglEnableClientState(GL_COLOR_ARRAY);\n");
			break;
		case 3:
			if(separate_arrays)
				source = prefix+"texcoord_data";
			IO::print("\tglTexCoordPointer(%d, GL_FLOAT, %d*sizeof(float), %s);\n",
				size, stride, source);
			IO::print("\tglEnableClientState(GL_TEXTURE_COORD_ARRAY);\n");
			break;
		default:
			if(kind<11)
			{
				if(separate_arrays)
					source = format("%stexcoord%d_data", prefix, kind-3);
				IO::print("\tglClientActiveTexture(GL_TEXTURE%d);\n", kind-3);
				IO::print("\tglTexCoordPointer(%d, GL_FLOAT, %d*sizeof(float), %s);\n",
					size, stride, source);
				IO::print("\tglEnableClientState(GL_TEXTURE_COORD_ARRAY);\n");
			}
			else
			{
				if(separate_arrays)
					source = format("%sattrib%d_data", prefix, kind-11);
				IO::print("\tglVertexAttribPointer(%d, %d, GL_FLOAT, GL_FALSE, %d*sizeof(float), %s);\n",
					kind-11, size, stride, source);
				IO::print("\tglEnableVertexAttribArray(%d);\n", kind-11);
			}
			break;
		}
		offset += size;
	}
	offset = 0;
	for(list<GL::Batch>::const_iterator i=mesh.get_batches().begin(); i!=mesh.get_batches().end(); ++i)
	{
		string mode;
		switch(i->get_type())
		{
		case GL_TRIANGLE_STRIP: mode = "GL_TRIANGLE_STRIP"; break;
		case GL_TRIANGLES: mode = "GL_TRIANGLES"; break;
		default: mode = format("%d", i->get_type()); break;
		}
		IO::print("\tglDrawElements(%s, %d, %s, %sindices+%d);\n", mode, i->size(), type[1], prefix, offset);
		offset += i->size();
	}
	if(render_func)
	{
		IO::print("}\n\n");
		IO::print("/* To render this object, #include this file and call %srender() */\n", prefix);
	}
	else
		IO::print("*/\n");

	return 0;
}