descent/TEXMAP/SCANLINE.C

/*
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: f:/miner/source/texmap/rcs/scanline.c $
 * $Revision: 1.2 $
 * $Author: john $
 * $Date: 1995/02/20 18:23:39 $
 * 
 * Routines to draw the texture mapped scanlines.
 * 
 * $Log: scanline.c $
 * Revision 1.2  1995/02/20  18:23:39  john
 * Added new module for C versions of inner loops.
 * 
 * Revision 1.1  1995/02/20  17:42:27  john
 * Initial revision
 * 
 * 
 */


#pragma off (unreferenced)
static char rcsid[] = "$Id: scanline.c 1.2 1995/02/20 18:23:39 john Exp $";
#pragma on (unreferenced)

#include <math.h>
#include <limits.h>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>

#include "fix.h"
#include "mono.h"
#include "gr.h"
#include "grdef.h"
#include "texmap.h"
#include "texmapl.h"
#include "scanline.h"

void c_tmap_scanline_flat()
{
	ubyte *dest;
	int x;

	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y )  );

	for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
		*dest++ = tmap_flat_color;
	}
}

void c_tmap_scanline_shaded()
{
	int fade;
	ubyte *dest;
	int x;

	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y)  );

	fade = tmap_flat_shade_value<<8;
	for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
		*dest++ = gr_fade_table[ fade |(*dest)];
	}
}

void c_tmap_scanline_lin_nolight()
{
	ubyte *dest;
	uint c;
	int x;
	fix u,v,dudx, dvdx;

	u = fx_u;
	v = fx_v*64;
	dudx = fx_du_dx; 
	dvdx = fx_dv_dx*64; 

	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y)  );

	if (!Transparency_on)	{
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			*dest++ = (uint)pixptr[ (f2i(v)&(64*63)) + (f2i(u)&63) ];
			u += dudx;
			v += dvdx;
		}
	} else {
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			c = (uint)pixptr[ (f2i(v)&(64*63)) + (f2i(u)&63) ];
			if ( c!=255)
				*dest = c;
			dest++;
			u += dudx;
			v += dvdx;
		}
	}
}


void c_tmap_scanline_lin()
{
	ubyte *dest;
	uint c;
	int x;
	fix u,v,l,dudx, dvdx, dldx;

	u = fx_u;
	v = fx_v*64;
	dudx = fx_du_dx; 
	dvdx = fx_dv_dx*64; 

	l = fx_l>>8;
	dldx = fx_dl_dx>>8;
	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y)  );

	if (!Transparency_on)	{
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			*dest++ = gr_fade_table[ (l&(0xff00)) + (uint)pixptr[ (f2i(v)&(64*63)) + (f2i(u)&63) ] ];
			l += dldx;
			u += dudx;
			v += dvdx;
		}
	} else {
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			c = (uint)pixptr[ (f2i(v)&(64*63)) + (f2i(u)&63) ];
			if ( c!=255)
				*dest = gr_fade_table[ (l&(0xff00)) + c ];
			dest++;
			l += dldx;
			u += dudx;
			v += dvdx;
		}
	}
}


void c_tmap_scanline_per_nolight()
{
	ubyte *dest;
	uint c;
	int x;
	fix u,v,z,dudx, dvdx, dzdx;

	u = fx_u;
	v = fx_v*64;
	z = fx_z;
	dudx = fx_du_dx; 
	dvdx = fx_dv_dx*64; 
	dzdx = fx_dz_dx;

	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y)  );

	if (!Transparency_on)	{
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			*dest++ = (uint)pixptr[ ( (v/z)&(64*63) ) + ((u/z)&63) ];
			u += dudx;
			v += dvdx;
			z += dzdx;
		}
	} else {
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			c = (uint)pixptr[ ( (v/z)&(64*63) ) + ((u/z)&63) ];
			if ( c!=255)
				*dest = c;
			dest++;
			u += dudx;
			v += dvdx;
			z += dzdx;
		}
	}
}

void c_tmap_scanline_per()
{
	ubyte *dest;
	uint c;
	int x;
	fix u,v,z,l,dudx, dvdx, dzdx, dldx;

	u = fx_u;
	v = fx_v*64;
	z = fx_z;
	dudx = fx_du_dx; 
	dvdx = fx_dv_dx*64; 
	dzdx = fx_dz_dx;

	l = fx_l>>8;
	dldx = fx_dl_dx>>8;
	dest = (ubyte *)(write_buffer + fx_xleft + (bytes_per_row * fx_y)  );

	if (!Transparency_on)	{
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			*dest++ = gr_fade_table[ (l&(0xff00)) + (uint)pixptr[ ( (v/z)&(64*63) ) + ((u/z)&63) ] ];
			l += dldx;
			u += dudx;
			v += dvdx;
			z += dzdx;
		}
	} else {
		for (x= fx_xright-fx_xleft+1 ; x > 0; --x ) {
			c = (uint)pixptr[ ( (v/z)&(64*63) ) + ((u/z)&63) ];
			if ( c!=255)
				*dest = gr_fade_table[ (l&(0xff00)) + c ];
			dest++;
			l += dldx;
			u += dudx;
			v += dvdx;
			z += dzdx;
		}
	}
}