/* Copyright Jeff Lassahn.  See graph3d.tex for details. */

#include "liftio.h"
#include <stdlib.h>
#include <math.h>


/* I/O primitives */
static FILE *myfp;
int PutInt(long x)
{
int i;
	for (i=0;i<4;i++) {
		if (EOF==putc(x&0xFF,myfp)) return 0;
		x>>=8;
	}
	return 1;
}

int PutFloat(float x)
{
long n;
int i;
	n=(long)(frexp(x,&i)*0x00400000L)&0x00FFFFFFL;
	n|=((long)i<<24);
	return PutInt(n);;
}

int PutByte(int x)
{
	if (EOF==putc(x&0xFF,myfp)) return 0;
	return 1;
}

int PutTag(char *x)
{
int i;
	for (i=0;i<4;i++) {
		if (EOF==putc(x[i],myfp)) return 0;
	}
	return 1;
}

int GetInt(int *x)
{
int i;
int c;
	*x=0;
	for (i=0;i<4;i++) {
		c=getc(myfp);
		if (c==EOF) return 0;
		*x|=((long)c)<<(i*8);
	}
	return 1;
}

int GetFloat(float *x)
{
int i;
int c;
long n;
	n=0;
	for (i=0;i<3;i++) {
		c=getc(myfp);
		if (c==EOF) return 0;
		n|=((long)c)<<(i*8);
	}
	if (n&0x00800000L)
		n|=-0x01000000L;
	c=getc(myfp);
	if (c==EOF) return 0;
	c=(int)(signed char)c;
	*x=ldexp(n,c-22);
	return 1;
}

int GetByte(unsigned char *x)
{
int c;
	c=getc(myfp);
	if (c==EOF) return 0;
	*x=c;
	return 1;
}

int GetTag(char *x)
{
int i,c;
	for (i=0;i<4;i++) {
		c=getc(myfp);
		if (c==EOF) return 0;
		x[i]=c;
	}
	return 1;
}

/* FILE FORMAT for parts:
	tag "PART"
	int nwindows
	int nvertices
	PG_OBJECTPART
		float detail;
		int npolys;
		PG_POLYGON [npolys]
			int nverts
			int verts [nverts]
		PG_VECTOR [npolys]
			float x,y,z
		PIX_RGB32 [npolys]
			byte r,g,b,a
		int npoints;
		PG_VECTOR [npoints]
			float x,y,z
		PG_POLYGON [nwindows]
			int nverts
			int verts [nverts]
		PG_VECTOR [nwindows]
			float x,y,z

*/

void StartFile(FILE *fp)
{
	myfp=fp;
}

void FreePart(OBJECTPART *p)
{
	if (p->verts)
		free(p->verts);
	if (p->part.polys)
		free(p->part.polys);
	if (p->part.norms)
		free(p->part.norms);
	if (p->part.colors)
		free(p->part.colors);
	if (p->part.points)
		free(p->part.points);
	if (p->part.windows)
		free(p->part.windows);
	if (p->part.wnorms)
		free(p->part.wnorms);
}

/* note: ReadPart doesn't read the tag at the front of the part,
because later we'll want a master read function wich reads the tag
and calls the correct reader. */

int ReadPart(OBJECTPART *p,FILE *fp)
{
int i,j,vp;
	StartFile(fp);
	p->verts=NULL;
	p->part.polys=NULL;
	p->part.norms=NULL;
	p->part.colors=NULL;
	p->part.points=NULL;
	p->part.windows=NULL;
	p->part.wnorms=NULL;

	if (!GetInt(&(p->nwindows))) goto die;
	if (!GetInt(&(p->nverts))) goto die;
	if (p->nverts<0) goto die;
	if (p->nverts>0) {
		p->verts=malloc(p->nverts*sizeof(int));
		if (!p->verts) goto die;
	}
	vp=0;

	if (!GetFloat(&(p->part.detail))) goto die;
	if (!GetInt(&(p->part.npolys))) goto die;
	if (p->part.npolys<0) goto die;
	if (p->part.npolys>0) {
		p->part.polys=malloc(p->part.npolys*sizeof(PG_POLYGON));
		if (!p->part.polys) goto die;
		p->part.norms=malloc(p->part.npolys*sizeof(PG_VECTOR));
		if (!p->part.norms) goto die;
		p->part.colors=malloc(p->part.npolys*sizeof(PIX_RGB32));
		if (!p->part.colors) goto die;
	}

	for (i=0;i<p->part.npolys;i++) {
		if (!GetInt(&(p->part.polys[i].n))) goto die;
		p->part.polys[i].points=&(p->verts[vp]);
		for (j=0;j<p->part.polys[i].n;j++) {
			if (!GetInt(&(p->verts[vp]))) goto die;
			vp++;
		}
	}
	for (i=0;i<p->part.npolys;i++) {
		if (!GetFloat(&(p->part.norms[i].x))) goto die;
		if (!GetFloat(&(p->part.norms[i].y))) goto die;
		if (!GetFloat(&(p->part.norms[i].z))) goto die;
	}
	for (i=0;i<p->part.npolys;i++) {
		if (!GetByte(&(p->part.colors[i].red))) goto die;
		if (!GetByte(&(p->part.colors[i].green))) goto die;
		if (!GetByte(&(p->part.colors[i].blue))) goto die;
		if (!GetByte(&(p->part.colors[i].alpha))) goto die;
	}

	if (!GetInt(&(p->part.npoints))) goto die;
	if (p->part.npoints<0) goto die;
	if (p->part.npoints>0) {
		p->part.points=malloc(p->part.npoints*sizeof(PG_VECTOR));
		if (!p->part.points) goto die;
	}
	for (i=0;i<p->part.npoints;i++) {
		if (!GetFloat(&(p->part.points[i].x))) goto die;
		if (!GetFloat(&(p->part.points[i].y))) goto die;
		if (!GetFloat(&(p->part.points[i].z))) goto die;
	}

	if (p->nwindows>0) {
		p->part.windows=malloc(p->nwindows*sizeof(PG_POLYGON));
		if (!p->part.windows) goto die;
		p->part.wnorms=malloc(p->nwindows*sizeof(PG_VECTOR));
		if (!p->part.wnorms) goto die;
	}
	for (i=0;i<p->nwindows;i++) {
		if (!GetInt(&(p->part.windows[i].n))) goto die;
		p->part.windows[i].points=&(p->verts[vp]);
		for (j=0;j<p->part.windows[i].n;j++) {
			if (!GetInt(&(p->verts[vp]))) goto die;
			vp++;
		}
	}
	for (i=0;i<p->nwindows;i++) {
		if (!GetFloat(&(p->part.wnorms[i].x))) goto die;
		if (!GetFloat(&(p->part.wnorms[i].y))) goto die;
		if (!GetFloat(&(p->part.wnorms[i].z))) goto die;
	}
	return 1;

die:
	FreePart(p);
	return 0;
}

int WritePart(OBJECTPART *p,FILE *fp)
{
int i,j;
	StartFile(fp);
	if (!PutTag("PART")) return 0;
	if (!PutInt(p->nwindows)) return 0;
	if (!PutInt(p->nverts)) return 0;

	if (!PutFloat(p->part.detail)) return 0;
	if (!PutInt(p->part.npolys)) return 0;

	for (i=0;i<p->part.npolys;i++) {
		if (!PutInt(p->part.polys[i].n)) return 0;
		for (j=0;j<p->part.polys[i].n;j++) {
			if (!PutInt(p->part.polys[i].points[j])) return 0;
		}
	}

	for (i=0;i<p->part.npolys;i++) {
		if (!PutFloat(p->part.norms[i].x)) return 0;
		if (!PutFloat(p->part.norms[i].y)) return 0;
		if (!PutFloat(p->part.norms[i].z)) return 0;
	}
	for (i=0;i<p->part.npolys;i++) {
		if (!PutByte(p->part.colors[i].red)) return 0;
		if (!PutByte(p->part.colors[i].green)) return 0;
		if (!PutByte(p->part.colors[i].blue)) return 0;
		if (!PutByte(p->part.colors[i].alpha)) return 0;
	}

	if (!PutInt(p->part.npoints)) return 0;
	for (i=0;i<p->part.npoints;i++) {
		if (!PutFloat(p->part.points[i].x)) return 0;
		if (!PutFloat(p->part.points[i].y)) return 0;
		if (!PutFloat(p->part.points[i].z)) return 0;
	}

	for (i=0;i<p->nwindows;i++) {
		if (!PutInt(p->part.windows[i].n)) return 0;
		for (j=0;j<p->part.windows[i].n;j++) {
			if (!PutInt(p->part.windows[i].points[j])) return 0;
		}
	}
	for (i=0;i<p->nwindows;i++) {
		if (!PutFloat(p->part.wnorms[i].x)) return 0;
		if (!PutFloat(p->part.wnorms[i].y)) return 0;
		if (!PutFloat(p->part.wnorms[i].z)) return 0;
	}
	return 1;
}