/*
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.  
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/
/*
 * $Source: Smoke:miner:source:3d::RCS:interp.c $
 * $Revision: 1.4 $
 * $Author: allender $
 * $Date: 1995/10/10 22:20:09 $
 * 
 * Polygon object interpreter
 * 
 * $Log: interp.c $
 * Revision 1.4  1995/10/10  22:20:09  allender
 * new morphing code from Matt
 *
 * Revision 1.3  1995/08/31  15:40:24  allender
 * swap color data correctly
 *
 * Revision 1.2  1995/05/11  13:06:38  allender
 * fix int --> short problem
 *
 * Revision 1.1  1995/05/05  08:51:41  allender
 * Initial revision
 *
 * Revision 1.1  1995/04/17  06:44:33  matt
 * Initial revision
 * 
 * 
 */

#pragma off (unreferenced)
static char rcsid[] = "$Id: interp.c 1.4 1995/10/10 22:20:09 allender Exp $";
#pragma on (unreferenced)

#include "error.h"

#include "3d.h"
#include "globvars.h"
#include "gr.h"

#include "byteswap.h"

#define OP_EOF				0	//eof
#define OP_DEFPOINTS		1	//defpoints
#define OP_FLATPOLY		2	//flat-shaded polygon
#define OP_TMAPPOLY		3	//texture-mapped polygon
#define OP_SORTNORM		4	//sort by normal
#define OP_RODBM			5	//rod bitmap
#define OP_SUBCALL		6	//call a subobject
#define OP_DEFP_START	7	//defpoints with start
#define OP_GLOW			8	//glow value for next poly

#define N_OPCODES (sizeof(opcode_table) / sizeof(*opcode_table))

#define MAX_POINTS_PER_POLY		25

short	highest_texture_num;
int	g3d_interp_outline;

g3s_point *Interp_point_list=NULL;

#define MAX_INTERP_COLORS 100

//this is a table of mappings from RGB15 to palette colors
struct {short pal_entry,rgb15;} interp_color_table[MAX_INTERP_COLORS];

int n_interp_colors=0;

//gives the interpreter an array of points to use
void g3_set_interp_points(g3s_point *pointlist)
{
	Interp_point_list = pointlist;
}

#define w(p)  (*((short *) (p)))
#define wp(p)  ((short *) (p))
#define vp(p)  ((vms_vector *) (p))

void rotate_point_list(g3s_point *dest,vms_vector *src,int n)
{
	while (n--)
		g3_rotate_point(dest++,src++);
}

vms_angvec zero_angles = {0,0,0};

g3s_point *point_list[MAX_POINTS_PER_POLY];

int glow_num = -1;

void short_swap(short *s)
{
	*s = swapshort(*s);
}

void vms_vector_swap(vms_vector *v)
{
	v->x = (fix)swapint((int)v->x);
	v->y = (fix)swapint((int)v->y);
	v->z = (fix)swapint((int)v->z);
}

void swap_polygon_model_data(ubyte *data)
{
	int i;
	short n;
	g3s_uvl *uvl_val;
	ubyte *p = data;

	short_swap(wp(p));

	while (w(p) != OP_EOF) {
		switch (w(p)) {
			case OP_DEFPOINTS:
				short_swap(wp(p + 2));
				n = w(p+2);
				for (i = 0; i < n; i++)
					vms_vector_swap(vp((p + 4) + (i * sizeof(vms_vector))));
				p += n*sizeof(struct vms_vector) + 4;
				break;

			case OP_DEFP_START:
				short_swap(wp(p + 2));
				short_swap(wp(p + 4));
				n = w(p+2);
				for (i = 0; i < n; i++)
					vms_vector_swap(vp((p + 8) + (i * sizeof(vms_vector))));
				p += n*sizeof(struct vms_vector) + 8;
				break;

			case OP_FLATPOLY:
				short_swap(wp(p+2));
				n = w(p+2);
				vms_vector_swap(vp(p + 4));
				vms_vector_swap(vp(p + 16));
				short_swap(wp(p+28));
// swap the colors 0 and 255 here!!!!
				if (w(p+28) == 0)
					w(p+28) = 255;
				else if (w(p+28) == 255)
					w(p+28) = 0;
				for (i=0; i < n; i++)
					short_swap(wp(p + 30 + (i * 2)));
				p += 30 + ((n&~1)+1)*2;
				break;

			case OP_TMAPPOLY:
				short_swap(wp(p+2));
				n = w(p+2);
				vms_vector_swap(vp(p + 4));
				vms_vector_swap(vp(p + 16));
				for (i=0;i<n;i++) {
					uvl_val = (g3s_uvl *)((p+30+((n&~1)+1)*2) + (i * sizeof(g3s_uvl)));
					uvl_val->u = (fix)swapint((int)uvl_val->u);
					uvl_val->v = (fix)swapint((int)uvl_val->v);
				}
				short_swap(wp(p+28));
				for (i=0;i<n;i++)
					short_swap(wp(p + 30 + (i * 2)));
				p += 30 + ((n&~1)+1)*2 + n*12;
				break;

			case OP_SORTNORM:
				vms_vector_swap(vp(p + 4));
				vms_vector_swap(vp(p + 16));
				short_swap(wp(p + 28));
				short_swap(wp(p + 30));
				swap_polygon_model_data(p + w(p+28));
				swap_polygon_model_data(p + w(p+30));
				p += 32;
				break;

			case OP_RODBM:
				vms_vector_swap(vp(p + 20));
				vms_vector_swap(vp(p + 4));
				short_swap(wp(p+2));
				*((int *)(p + 16)) = swapint(*((int *)(p + 16)));
				*((int *)(p + 32)) = swapint(*((int *)(p + 32)));
				p+=36;
				break;

			case OP_SUBCALL:
				short_swap(wp(p+2));
				vms_vector_swap(vp(p+4));
				short_swap(wp(p+16));
				swap_polygon_model_data(p + w(p+16));
				p += 20;
				break;

			case OP_GLOW:
				short_swap(wp(p + 2));
				p += 4;
				break;
				
			default:
				Int3();
		}
		short_swap(wp(p));
	}
}

//calls the object interpreter to render an object.  The object renderer
//is really a seperate pipeline. returns true if drew
bool g3_draw_polygon_model(void *model_ptr,grs_bitmap **model_bitmaps,vms_angvec *anim_angles,fix model_light,fix *glow_values)
{
	ubyte *p = model_ptr;
	int current_poly = 0;

	glow_num = -1;		//glow off by default

	while (w(p) != OP_EOF)

		switch (w(p)) {

			case OP_DEFPOINTS: {
				int n = w(p+2);

				rotate_point_list(Interp_point_list,vp(p+4),n);
				p += n*sizeof(struct vms_vector) + 4;

				break;
			}

			case OP_DEFP_START: {
				int n = w(p+2);
				int s = w(p+4);

				rotate_point_list(&Interp_point_list[s],vp(p+8),n);
				p += n*sizeof(struct vms_vector) + 8;

				break;
			}

			case OP_FLATPOLY: {
				int nv = w(p+2);

				Assert( nv < MAX_POINTS_PER_POLY );
				if (g3_check_normal_facing(vp(p+4),vp(p+16)) > 0) {
					int i;

					gr_setcolor(w(p+28));

					for (i=0;i<nv;i++)
						point_list[i] = Interp_point_list + wp(p+30)[i];

					g3_draw_poly(nv,point_list);
				}

				p += 30 + ((nv&~1)+1)*2;
					
				break;
			}

			case OP_TMAPPOLY: {
				int nv = w(p+2);
				g3s_uvl *uvl_list;

				Assert( nv < MAX_POINTS_PER_POLY );
				if (g3_check_normal_facing(vp(p+4),vp(p+16)) > 0) {
					int i;
					fix light;

					//calculate light from surface normal

					if (glow_num < 0) {			//no glow

						light = -vm_vec_dot(&View_matrix.fvec,vp(p+16));
						light = f1_0/4 + (light*3)/4;
						light = fixmul(light,model_light);
					}
					else {				//yes glow
						light = glow_values[glow_num];
						glow_num = -1;
					}

					//now poke light into l values

					uvl_list = (g3s_uvl *) (p+30+((nv&~1)+1)*2);

					for (i=0;i<nv;i++)
						uvl_list[i].l = light;

					for (i=0;i<nv;i++)
						point_list[i] = Interp_point_list + wp(p+30)[i];

					g3_draw_tmap(nv,point_list,uvl_list,model_bitmaps[w(p+28)]);
				}

				p += 30 + ((nv&~1)+1)*2 + nv*12;
					
				break;
			}

			case OP_SORTNORM:

				if (g3_check_normal_facing(vp(p+16),vp(p+4)) > 0) {		//facing

					//draw back then front

					g3_draw_polygon_model(p+w(p+30),model_bitmaps,anim_angles,model_light,glow_values);
					g3_draw_polygon_model(p+w(p+28),model_bitmaps,anim_angles,model_light,glow_values);

				}
				else {			//not facing.  draw front then back

					g3_draw_polygon_model(p+w(p+28),model_bitmaps,anim_angles,model_light,glow_values);
					g3_draw_polygon_model(p+w(p+30),model_bitmaps,anim_angles,model_light,glow_values);
				}

				p += 32;

				break;


			case OP_RODBM: {
				g3s_point rod_bot_p,rod_top_p;

				g3_rotate_point(&rod_bot_p,vp(p+20));
				g3_rotate_point(&rod_top_p,vp(p+4));

				g3_draw_rod_tmap(model_bitmaps[w(p+2)],&rod_bot_p,w(p+16),&rod_top_p,w(p+32),f1_0);

				p+=36;
				break;
			}

			case OP_SUBCALL: {
				vms_angvec *a;

				if (anim_angles)
					a = &anim_angles[w(p+2)];
				else
					a = &zero_angles;

				g3_start_instance_angles(vp(p+4),a);

				g3_draw_polygon_model(p+w(p+16),model_bitmaps,anim_angles,model_light,glow_values);

				g3_done_instance();

				p += 20;

				break;

			}

			case OP_GLOW:

				if (glow_values)
					glow_num = w(p+2);
				p += 4;
				break;

			default:
				Int3();
		}
	return 1;
}

extern int gr_find_closest_color_15bpp( int rgb );

#ifndef NDEBUG
int nest_count;
#endif

#pragma off (unreferenced)

//alternate interpreter for morphing object
bool g3_draw_morphing_model(void *model_ptr,grs_bitmap **model_bitmaps,vms_angvec *anim_angles,fix model_light,vms_vector *new_points)
{
	ubyte *p = model_ptr;
	fix *glow_values = NULL;

	glow_num = -1;		//glow off by default

	while (w(p) != OP_EOF)

		switch (w(p)) {

			case OP_DEFPOINTS: {
				int n = w(p+2);

				rotate_point_list(Interp_point_list,new_points,n);
				p += n*sizeof(struct vms_vector) + 4;

				break;
			}

			case OP_DEFP_START: {
				int n = w(p+2);
				int s = w(p+4);

				rotate_point_list(&Interp_point_list[s],new_points,n);
				p += n*sizeof(struct vms_vector) + 8;

				break;
			}

			case OP_FLATPOLY: {
				int nv = w(p+2);
				int i,ntris;

				gr_setcolor(w(p+28));
				
				for (i=0;i<2;i++)
					point_list[i] = Interp_point_list + wp(p+30)[i];

				for (ntris=nv-2;ntris;ntris--) {

					point_list[2] = Interp_point_list + wp(p+30)[i++];

					g3_check_and_draw_poly(3,point_list,NULL,NULL);

					point_list[1] = point_list[2];

				}

				p += 30 + ((nv&~1)+1)*2;
					
				break;
			}

			case OP_TMAPPOLY: {
				int nv = w(p+2);
				g3s_uvl *uvl_list;
				g3s_uvl morph_uvls[3];
				int i,ntris;
				fix light;

				//calculate light from surface normal

				if (glow_num < 0) {			//no glow

					light = -vm_vec_dot(&View_matrix.fvec,vp(p+16));
					light = f1_0/4 + (light*3)/4;
					light = fixmul(light,model_light);
				}
				else {				//yes glow
					light = glow_values[glow_num];
					glow_num = -1;
				}

				//now poke light into l values

				uvl_list = (g3s_uvl *) (p+30+((nv&~1)+1)*2);

				for (i=0;i<3;i++)
					morph_uvls[i].l = light;

				for (i=0;i<2;i++) {
					point_list[i] = Interp_point_list + wp(p+30)[i];

					morph_uvls[i].u = uvl_list[i].u;
					morph_uvls[i].v = uvl_list[i].v;
				}

				for (ntris=nv-2;ntris;ntris--) {

					point_list[2] = Interp_point_list + wp(p+30)[i];
					morph_uvls[2].u = uvl_list[i].u;
					morph_uvls[2].v = uvl_list[i].v;
					i++;

					g3_check_and_draw_tmap(3,point_list,uvl_list,model_bitmaps[w(p+28)],NULL,NULL);

					point_list[1] = point_list[2];
					morph_uvls[1].u = morph_uvls[2].u;
					morph_uvls[1].v = morph_uvls[2].v;

				}

				p += 30 + ((nv&~1)+1)*2 + nv*12;

				break;
			}

			case OP_SORTNORM:

				if (g3_check_normal_facing(vp(p+16),vp(p+4)) > 0) {		//facing

					//draw back then front

					g3_draw_morphing_model(p+w(p+30),model_bitmaps,anim_angles,model_light,new_points);
					g3_draw_morphing_model(p+w(p+28),model_bitmaps,anim_angles,model_light,new_points);

				}
				else {			//not facing.  draw front then back

					g3_draw_morphing_model(p+w(p+28),model_bitmaps,anim_angles,model_light,new_points);
					g3_draw_morphing_model(p+w(p+30),model_bitmaps,anim_angles,model_light,new_points);
				}

				p += 32;

				break;


			case OP_RODBM: {
				g3s_point rod_bot_p,rod_top_p;

				g3_rotate_point(&rod_bot_p,vp(p+20));
				g3_rotate_point(&rod_top_p,vp(p+4));

				g3_draw_rod_tmap(model_bitmaps[w(p+2)],&rod_bot_p,w(p+16),&rod_top_p,w(p+32),f1_0);

				p+=36;
				break;
			}

			case OP_SUBCALL: {
				vms_angvec *a;

				if (anim_angles)
					a = &anim_angles[w(p+2)];
				else
					a = &zero_angles;

				g3_start_instance_angles(vp(p+4),a);

				g3_draw_polygon_model(p+w(p+16),model_bitmaps,anim_angles,model_light,glow_values);

				g3_done_instance();

				p += 20;

				break;

			}

			case OP_GLOW:

				if (glow_values)
					glow_num = w(p+2);
				p += 4;
				break;
		}

	return 1;
}

void init_model_sub(ubyte *p)
{
	Assert(++nest_count < 1000);

	while (w(p) != OP_EOF) {

		switch (w(p)) {

			case OP_DEFPOINTS: {
				int n = w(p+2);
				p += n*sizeof(struct vms_vector) + 4;
				break;
			}

			case OP_DEFP_START: {
				int n = w(p+2);
				p += n*sizeof(struct vms_vector) + 8;
				break;
			}

			case OP_FLATPOLY: {
				int i, nv = w(p+2);

				Assert(nv > 2);		//must have 3 or more points

				*wp(p+28) = (short)gr_find_closest_color_15bpp(w(p+28));

				p += 30 + ((nv&~1)+1)*2;
					
				break;
			}

			case OP_TMAPPOLY: {
				int nv = w(p+2);

				Assert(nv > 2);		//must have 3 or more points

				if (w(p+28) > highest_texture_num)
					highest_texture_num = w(p+28);

				p += 30 + ((nv&~1)+1)*2 + nv*12;
					
				break;
			}

			case OP_SORTNORM:

				init_model_sub(p+w(p+28));
				init_model_sub(p+w(p+30));
				p += 32;

				break;


			case OP_RODBM:
				p += 36;
				break;


			case OP_SUBCALL: {
				init_model_sub(p+w(p+16));
				p += 20;
				break;

			}

			case OP_GLOW:
				p += 4;
				break;
		}
	}
}

//init code for bitmap models
void g3_init_polygon_model(void *model_ptr)
{
	#ifndef NDEBUG
	nest_count = 0;
	#endif

	highest_texture_num = -1;

	init_model_sub((ubyte *) model_ptr);
}