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/*
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 .
*/
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/*
*
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* Start of conversion to new texture mapper .
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*
*/
# define VESA 0
# define NUM_TMAPS 16
# define HEADLIGHT_LIGHTING 0
# define WIREFRAME 0
# define PERSPECTIVE 1
# include <math.h>
# include <limits.h>
# include <stdio.h>
# include <stdlib.h>
# include "3d.h"
# include "gr.h"
# include "error.h"
# include "texmap.h"
# include "texmapl.h"
# include "rle.h"
# include "scanline.h"
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# include "render.h"
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# include "../main/textures.h"
# ifdef EDITOR
# define EDITOR_TMAP 1 //if in, include extra stuff
# endif
# define F15_5 (F1_0*15 + F0_5)
// Temporary texture map, interface from Matt's 3d system to Mike's texture mapper.
g3ds_tmap Tmap1 ;
grs_bitmap Texmap_ptrs [ NUM_TMAPS ] ;
grs_bitmap Texmap4_ptrs [ NUM_TMAPS ] ;
fix Range_max = 0 ; // debug, kill me
int Interpolation_method = 0 ; // 0 = choose best method
int Lighting_on = 1 ; // initialize to no lighting
int Tmap_flat_flag = 0 ; // 1 = render texture maps as flat shaded polygons.
int Current_seg_depth ; // HACK INTERFACE: how far away the current segment (& thus texture) is
int Max_perspective_depth ;
int Max_flat_depth ;
extern int Window_clip_left , Window_clip_bot , Window_clip_right , Window_clip_top ;
// These variables are the interface to assembler. They get set for each texture map, which is a real waste of time.
// They should be set only when they change, which is generally when the window bounds change. And, even still, it's
// a pretty bad interface.
int bytes_per_row = - 1 ;
unsigned char * write_buffer ;
int window_left ;
int window_right ;
int window_top ;
int window_bottom ;
int window_width ;
int window_height ;
# ifdef EDITOR_TMAP
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# define MAX_Y_POINTERS 1024
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# else
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# define MAX_Y_POINTERS 1024
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# endif
int y_pointers [ MAX_Y_POINTERS ] ;
fix fix_recip [ FIX_RECIP_TABLE_SIZE ] ;
int Lighting_enabled ;
int Fix_recip_table_computed = 0 ;
fix fx_l , fx_u , fx_v , fx_z , fx_du_dx , fx_dv_dx , fx_dz_dx , fx_dl_dx ;
int fx_xleft , fx_xright , fx_y ;
unsigned char * pixptr ;
int per2_flag = 0 ;
int Transparency_on = 0 ;
int dither_intensity_lighting = 0 ;
ubyte * tmap_flat_cthru_table ;
ubyte tmap_flat_color ;
ubyte tmap_flat_shade_value ;
// -------------------------------------------------------------------------------------
void init_fix_recip_table ( void )
{
int i ;
fix_recip [ 0 ] = F1_0 ;
for ( i = 1 ; i < FIX_RECIP_TABLE_SIZE ; i + + )
fix_recip [ i ] = F1_0 / i ;
Fix_recip_table_computed = 1 ;
}
// -------------------------------------------------------------------------------------
// Initialize interface variables to assembler.
// These things used to be constants. This routine is now (10/6/93) getting called for
// every texture map. It should get called whenever the window changes, or, preferably,
// not at all. I'm pretty sure these variables are only being used for range checking.
void init_interface_vars_to_assembler ( void )
{
grs_bitmap * bp ;
bp = & grd_curcanv - > cv_bitmap ;
Assert ( bp ! = NULL ) ;
Assert ( bp - > bm_data ! = NULL ) ;
Assert ( bp - > bm_h < = MAX_Y_POINTERS ) ;
// If bytes_per_row has changed, create new table of pointers.
if ( bytes_per_row ! = ( int ) bp - > bm_rowsize ) {
int y_val , i ;
bytes_per_row = ( int ) bp - > bm_rowsize ;
y_val = 0 ;
for ( i = 0 ; i < MAX_Y_POINTERS ; i + + ) {
y_pointers [ i ] = y_val ;
y_val + = bytes_per_row ;
}
}
write_buffer = ( unsigned char * ) bp - > bm_data ;
window_left = 0 ;
window_right = ( int ) bp - > bm_w - 1 ;
window_top = 0 ;
window_bottom = ( int ) bp - > bm_h - 1 ;
Window_clip_left = window_left ;
Window_clip_right = window_right ;
Window_clip_top = window_top ;
Window_clip_bot = window_bottom ;
window_width = bp - > bm_w ;
window_height = bp - > bm_h ;
if ( ! Fix_recip_table_computed )
init_fix_recip_table ( ) ;
}
// -------------------------------------------------------------------------------------
// VARIABLES
extern g3ds_tmap Tmap1 ;
// -------------------------------------------------------------------------------------
// Returns number preceding val modulo modulus.
// prevmod(3,4) = 2
// prevmod(0,4) = 3
int prevmod ( int val , int modulus )
{
if ( val > 0 )
return val - 1 ;
else
return modulus - 1 ;
// return (val + modulus - 1) % modulus;
}
// Returns number succeeding val modulo modulus.
// succmod(3,4) = 0
// succmod(0,4) = 1
int succmod ( int val , int modulus )
{
if ( val < modulus - 1 )
return val + 1 ;
else
return 0 ;
// return (val + 1) % modulus;
}
// -------------------------------------------------------------------------------------
// Select topmost vertex (minimum y coordinate) and bottommost (maximum y coordinate) in
// texture map. If either is part of a horizontal edge, then select leftmost vertex for
// top, rightmost vertex for bottom.
// Important: Vertex is selected with integer precision. So, if there are vertices at
// (0.0,0.7) and (0.5,0.3), the first vertex is selected, because they y coordinates are
// considered the same, so the smaller x is favored.
// Parameters:
// nv number of vertices
// v3d pointer to 3d vertices containing u,v,x2d,y2d coordinates
// Results in:
// *min_y_ind
// *max_y_ind
// -------------------------------------------------------------------------------------
void compute_y_bounds ( g3ds_tmap * t , int * vlt , int * vlb , int * vrt , int * vrb , int * bottom_y_ind )
{
int i ;
int min_y , max_y ;
int min_y_ind ;
int original_vrt ;
fix min_x ;
// Scan all vertices, set min_y_ind to vertex with smallest y coordinate.
min_y = f2i ( t - > verts [ 0 ] . y2d ) ;
max_y = min_y ;
min_y_ind = 0 ;
min_x = f2i ( t - > verts [ 0 ] . x2d ) ;
* bottom_y_ind = 0 ;
for ( i = 1 ; i < t - > nv ; i + + ) {
if ( f2i ( t - > verts [ i ] . y2d ) < min_y ) {
min_y = f2i ( t - > verts [ i ] . y2d ) ;
min_y_ind = i ;
min_x = f2i ( t - > verts [ i ] . x2d ) ;
} else if ( f2i ( t - > verts [ i ] . y2d ) = = min_y ) {
if ( f2i ( t - > verts [ i ] . x2d ) < min_x ) {
min_y_ind = i ;
min_x = f2i ( t - > verts [ i ] . x2d ) ;
}
}
if ( f2i ( t - > verts [ i ] . y2d ) > max_y ) {
max_y = f2i ( t - > verts [ i ] . y2d ) ;
* bottom_y_ind = i ;
}
}
//--removed mk, 11/27/94-- // Check for a non-upright-hourglass polygon and fix, if necessary, by bashing a y coordinate.
//--removed mk, 11/27/94-- // min_y_ind = index of minimum y coordinate, *bottom_y_ind = index of maximum y coordinate
//--removed mk, 11/27/94--{
//--removed mk, 11/27/94-- int max_temp, min_temp;
//--removed mk, 11/27/94--
//--removed mk, 11/27/94-- max_temp = *bottom_y_ind;
//--removed mk, 11/27/94-- if (*bottom_y_ind < min_y_ind)
//--removed mk, 11/27/94-- max_temp += t->nv;
//--removed mk, 11/27/94--
//--removed mk, 11/27/94-- for (i=min_y_ind; i<max_temp; i++) {
//--removed mk, 11/27/94-- if (f2i(t->verts[i%t->nv].y2d) > f2i(t->verts[(i+1)%t->nv].y2d)) {
//--removed mk, 11/27/94-- Int3();
//--removed mk, 11/27/94-- t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
//--removed mk, 11/27/94-- }
//--removed mk, 11/27/94-- }
//--removed mk, 11/27/94--
//--removed mk, 11/27/94-- min_temp = min_y_ind;
//--removed mk, 11/27/94-- if (min_y_ind < *bottom_y_ind)
//--removed mk, 11/27/94-- min_temp += t->nv;
//--removed mk, 11/27/94--
//--removed mk, 11/27/94-- for (i=*bottom_y_ind; i<min_temp; i++) {
//--removed mk, 11/27/94-- if (f2i(t->verts[i%t->nv].y2d) < f2i(t->verts[(i+1)%t->nv].y2d)) {
//--removed mk, 11/27/94-- Int3();
//--removed mk, 11/27/94-- t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
//--removed mk, 11/27/94-- }
//--removed mk, 11/27/94-- }
//--removed mk, 11/27/94--}
// Set "vertex left top", etc. based on vertex with topmost y coordinate
* vlt = min_y_ind ;
* vrt = * vlt ;
* vlb = prevmod ( * vlt , t - > nv ) ;
* vrb = succmod ( * vrt , t - > nv ) ;
// If right edge is horizontal, then advance along polygon bound until it no longer is or until all
// vertices have been examined.
// (Left edge cannot be horizontal, because *vlt is set to leftmost point with highest y coordinate.)
original_vrt = * vrt ;
while ( f2i ( t - > verts [ * vrt ] . y2d ) = = f2i ( t - > verts [ * vrb ] . y2d ) ) {
if ( succmod ( * vrt , t - > nv ) = = original_vrt ) {
break ;
}
* vrt = succmod ( * vrt , t - > nv ) ;
* vrb = succmod ( * vrt , t - > nv ) ;
}
}
// -------------------------------------------------------------------------------------
// Returns dx/dy given two vertices.
// If dy == 0, returns 0.0
// -------------------------------------------------------------------------------------
//--fix compute_dx_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex)
//--{
//-- int dy;
//--
//-- // compute delta x with respect to y for any edge
//-- dy = f2i(t->verts[bottom_vertex].y2d - t->verts[top_vertex].y2d) + 1;
//-- if (dy)
//-- return (t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d) / dy;
//-- else
//-- return 0;
//--
//--}
fix compute_du_dy_lin ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( t - > verts [ bottom_vertex ] . u - t - > verts [ top_vertex ] . u , recip_dy ) ;
}
fix compute_dv_dy_lin ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( t - > verts [ bottom_vertex ] . v - t - > verts [ top_vertex ] . v , recip_dy ) ;
}
fix compute_dl_dy_lin ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( t - > verts [ bottom_vertex ] . l - t - > verts [ top_vertex ] . l , recip_dy ) ;
}
fix compute_dx_dy ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( t - > verts [ bottom_vertex ] . x2d - t - > verts [ top_vertex ] . x2d , recip_dy ) ;
}
fix compute_du_dy ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( fixmul ( t - > verts [ bottom_vertex ] . u , t - > verts [ bottom_vertex ] . z ) - fixmul ( t - > verts [ top_vertex ] . u , t - > verts [ top_vertex ] . z ) , recip_dy ) ;
}
fix compute_dv_dy ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( fixmul ( t - > verts [ bottom_vertex ] . v , t - > verts [ bottom_vertex ] . z ) - fixmul ( t - > verts [ top_vertex ] . v , t - > verts [ top_vertex ] . z ) , recip_dy ) ;
}
fix compute_dz_dy ( g3ds_tmap * t , int top_vertex , int bottom_vertex , fix recip_dy )
{
return fixmul ( t - > verts [ bottom_vertex ] . z - t - > verts [ top_vertex ] . z , recip_dy ) ;
}
int Skip_short_flag = 0 ;
// -------------------------------------------------------------------------------------
// Texture map current scanline in perspective.
// -------------------------------------------------------------------------------------
void ntmap_scanline_lighted ( grs_bitmap * srcb , int y , fix xleft , fix xright , fix uleft , fix uright , fix vleft , fix vright , fix zleft , fix zright , fix lleft , fix lright )
{
fix dx , recip_dx ;
fx_xright = f2i ( xright ) ;
//edited 06/27/99 Matt Mueller - moved these tests up from within the switch so as not to do a bunch of needless calculations when we are just gonna return anyway. Slight fps boost?
if ( fx_xright < Window_clip_left )
return ;
fx_xleft = f2i ( xleft ) ;
if ( fx_xleft > Window_clip_right )
return ;
//end edit -MM
dx = fx_xright - fx_xleft ;
if ( ( dx < 0 ) | | ( xright < 0 ) | | ( xleft > xright ) ) // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
return ;
// setup to call assembler scanline renderer
if ( dx < FIX_RECIP_TABLE_SIZE )
recip_dx = fix_recip [ dx ] ;
else
recip_dx = F1_0 / dx ;
fx_u = uleft ;
fx_v = vleft ;
fx_z = zleft ;
fx_du_dx = fixmul ( uright - uleft , recip_dx ) ;
fx_dv_dx = fixmul ( vright - vleft , recip_dx ) ;
fx_dz_dx = fixmul ( zright - zleft , recip_dx ) ;
fx_y = y ;
pixptr = srcb - > bm_data ;
switch ( Lighting_enabled ) {
case 0 :
//added 05/17/99 Matt Mueller - prevent writing before the buffer
if ( ( fx_y = = 0 ) & & ( fx_xleft < 0 ) )
fx_xleft = 0 ;
//end addition -MM
if ( fx_xright > Window_clip_right )
fx_xright = Window_clip_right ;
cur_tmap_scanline_per ( ) ;
break ;
case 1 : {
fix mul_thing ;
if ( lleft < 0 ) lleft = 0 ;
if ( lright < 0 ) lright = 0 ;
if ( lleft > ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) ) lleft = ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) ;
if ( lright > ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) ) lright = ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) ;
fx_l = lleft ;
fx_dl_dx = fixmul ( lright - lleft , recip_dx ) ;
// This is a pretty ugly hack to prevent lighting overflows.
mul_thing = dx * fx_dl_dx ;
if ( lleft + mul_thing < 0 )
fx_dl_dx + = 12 ;
else if ( lleft + mul_thing > ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) )
fx_dl_dx - = 12 ;
//added 05/17/99 Matt Mueller - prevent writing before the buffer
if ( ( fx_y = = 0 ) & & ( fx_xleft < 0 ) )
fx_xleft = 0 ;
//end addition -MM
if ( fx_xright > Window_clip_right )
fx_xright = Window_clip_right ;
cur_tmap_scanline_per ( ) ;
break ;
}
case 2 :
# ifdef EDITOR_TMAP
fx_xright = f2i ( xright ) ;
fx_xleft = f2i ( xleft ) ;
tmap_flat_color = 1 ;
cur_tmap_scanline_flat ( ) ;
# else
Int3 ( ) ; // Illegal, called an editor only routine!
# endif
break ;
}
}
int Do_vertical_scan = 0 ;
int Break_on_flat = 0 ;
// -------------------------------------------------------------------------------------
// Render a texture map with lighting using perspective interpolation in inner and outer loops.
// -------------------------------------------------------------------------------------
void ntexture_map_lighted ( grs_bitmap * srcb , g3ds_tmap * t )
{
int vlt , vrt , vlb , vrb ; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
int topy , boty , y , dy ;
fix dx_dy_left , dx_dy_right ;
fix du_dy_left , du_dy_right ;
fix dv_dy_left , dv_dy_right ;
fix dz_dy_left , dz_dy_right ;
fix dl_dy_left , dl_dy_right ;
fix recip_dyl , recip_dyr ;
int max_y_vertex ;
fix xleft , xright , uleft , vleft , uright , vright , zleft , zright , lleft , lright ;
int next_break_left , next_break_right ;
g3ds_vertex * v3d ;
//remove stupid warnings in compile
dl_dy_left = F1_0 ;
dl_dy_right = F1_0 ;
lleft = F1_0 ;
lright = F1_0 ;
v3d = t - > verts ;
// Determine top and bottom y coords.
compute_y_bounds ( t , & vlt , & vlb , & vrt , & vrb , & max_y_vertex ) ;
// Set top and bottom (of entire texture map) y coordinates.
topy = f2i ( v3d [ vlt ] . y2d ) ;
boty = f2i ( v3d [ max_y_vertex ] . y2d ) ;
if ( topy > Window_clip_bot )
return ;
if ( boty > Window_clip_bot )
boty = Window_clip_bot ;
// Set amount to change x coordinate for each advance to next scanline.
dy = f2i ( t - > verts [ vlb ] . y2d ) - f2i ( t - > verts [ vlt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dyl = fix_recip [ dy ] ;
else
recip_dyl = F1_0 / dy ;
dx_dy_left = compute_dx_dy ( t , vlt , vlb , recip_dyl ) ;
du_dy_left = compute_du_dy ( t , vlt , vlb , recip_dyl ) ;
dv_dy_left = compute_dv_dy ( t , vlt , vlb , recip_dyl ) ;
dz_dy_left = compute_dz_dy ( t , vlt , vlb , recip_dyl ) ;
dy = f2i ( t - > verts [ vrb ] . y2d ) - f2i ( t - > verts [ vrt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dyr = fix_recip [ dy ] ;
else
recip_dyr = F1_0 / dy ;
du_dy_right = compute_du_dy ( t , vrt , vrb , recip_dyr ) ;
dx_dy_right = compute_dx_dy ( t , vrt , vrb , recip_dyr ) ;
dv_dy_right = compute_dv_dy ( t , vrt , vrb , recip_dyr ) ;
dz_dy_right = compute_dz_dy ( t , vrt , vrb , recip_dyr ) ;
if ( Lighting_enabled ) {
dl_dy_left = compute_dl_dy_lin ( t , vlt , vlb , recip_dyl ) ;
dl_dy_right = compute_dl_dy_lin ( t , vrt , vrb , recip_dyr ) ;
lleft = v3d [ vlt ] . l ;
lright = v3d [ vrt ] . l ;
}
// Set initial values for x, u, v
xleft = v3d [ vlt ] . x2d ;
xright = v3d [ vrt ] . x2d ;
zleft = v3d [ vlt ] . z ;
zright = v3d [ vrt ] . z ;
uleft = fixmul ( v3d [ vlt ] . u , zleft ) ;
uright = fixmul ( v3d [ vrt ] . u , zright ) ;
vleft = fixmul ( v3d [ vlt ] . v , zleft ) ;
vright = fixmul ( v3d [ vrt ] . v , zright ) ;
// scan all rows in texture map from top through first break.
next_break_left = f2i ( v3d [ vlb ] . y2d ) ;
next_break_right = f2i ( v3d [ vrb ] . y2d ) ;
for ( y = topy ; y < boty ; y + + ) {
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x,u,v
if ( y = = next_break_left ) {
fix recip_dy ;
// Handle problem of double points. Search until y coord is different. Cannot get
// hung in an infinite loop because we know there is a vertex with a lower y coordinate
// because in the for loop, we don't scan all spanlines.
while ( y = = f2i ( v3d [ vlb ] . y2d ) ) {
vlt = vlb ;
vlb = prevmod ( vlb , t - > nv ) ;
}
next_break_left = f2i ( v3d [ vlb ] . y2d ) ;
dy = f2i ( t - > verts [ vlb ] . y2d ) - f2i ( t - > verts [ vlt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dy = fix_recip [ dy ] ;
else
recip_dy = F1_0 / dy ;
dx_dy_left = compute_dx_dy ( t , vlt , vlb , recip_dy ) ;
xleft = v3d [ vlt ] . x2d ;
zleft = v3d [ vlt ] . z ;
uleft = fixmul ( v3d [ vlt ] . u , zleft ) ;
vleft = fixmul ( v3d [ vlt ] . v , zleft ) ;
lleft = v3d [ vlt ] . l ;
du_dy_left = compute_du_dy ( t , vlt , vlb , recip_dy ) ;
dv_dy_left = compute_dv_dy ( t , vlt , vlb , recip_dy ) ;
dz_dy_left = compute_dz_dy ( t , vlt , vlb , recip_dy ) ;
if ( Lighting_enabled ) {
dl_dy_left = compute_dl_dy_lin ( t , vlt , vlb , recip_dy ) ;
lleft = v3d [ vlt ] . l ;
}
}
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x. Not necessary to set new values for u,v.
if ( y = = next_break_right ) {
fix recip_dy ;
while ( y = = f2i ( v3d [ vrb ] . y2d ) ) {
vrt = vrb ;
vrb = succmod ( vrb , t - > nv ) ;
}
next_break_right = f2i ( v3d [ vrb ] . y2d ) ;
dy = f2i ( t - > verts [ vrb ] . y2d ) - f2i ( t - > verts [ vrt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dy = fix_recip [ dy ] ;
else
recip_dy = F1_0 / dy ;
dx_dy_right = compute_dx_dy ( t , vrt , vrb , recip_dy ) ;
xright = v3d [ vrt ] . x2d ;
zright = v3d [ vrt ] . z ;
uright = fixmul ( v3d [ vrt ] . u , zright ) ;
vright = fixmul ( v3d [ vrt ] . v , zright ) ;
du_dy_right = compute_du_dy ( t , vrt , vrb , recip_dy ) ;
dv_dy_right = compute_dv_dy ( t , vrt , vrb , recip_dy ) ;
dz_dy_right = compute_dz_dy ( t , vrt , vrb , recip_dy ) ;
if ( Lighting_enabled ) {
dl_dy_right = compute_dl_dy_lin ( t , vrt , vrb , recip_dy ) ;
lright = v3d [ vrt ] . l ;
}
}
if ( Lighting_enabled ) {
if ( y > = Window_clip_top )
ntmap_scanline_lighted ( srcb , y , xleft , xright , uleft , uright , vleft , vright , zleft , zright , lleft , lright ) ;
lleft + = dl_dy_left ;
lright + = dl_dy_right ;
} else
if ( y > = Window_clip_top )
ntmap_scanline_lighted ( srcb , y , xleft , xright , uleft , uright , vleft , vright , zleft , zright , lleft , lright ) ;
uleft + = du_dy_left ;
vleft + = dv_dy_left ;
uright + = du_dy_right ;
vright + = dv_dy_right ;
xleft + = dx_dy_left ;
xright + = dx_dy_right ;
zleft + = dz_dy_left ;
zright + = dz_dy_right ;
}
// We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
// but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
ntmap_scanline_lighted ( srcb , y , xleft , xright , uleft , uright , vleft , vright , zleft , zright , lleft , lright ) ;
}
// -------------------------------------------------------------------------------------
// Texture map current scanline using linear interpolation.
// -------------------------------------------------------------------------------------
void ntmap_scanline_lighted_linear ( grs_bitmap * srcb , int y , fix xleft , fix xright , fix uleft , fix uright , fix vleft , fix vright , fix lleft , fix lright )
{
fix u , v , l ;
fix dx , recip_dx ;
fix du_dx , dv_dx , dl_dx ;
u = uleft ;
v = vleft ;
l = lleft ;
dx = f2i ( xright ) - f2i ( xleft ) ;
if ( ( dx < 0 ) | | ( xright < 0 ) | | ( xleft > xright ) ) // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
return ;
// setup to call assembler scanline renderer
if ( dx < FIX_RECIP_TABLE_SIZE )
recip_dx = fix_recip [ dx ] ;
else
recip_dx = F1_0 / dx ;
du_dx = fixmul ( uright - uleft , recip_dx ) ;
dv_dx = fixmul ( vright - vleft , recip_dx ) ;
fx_u = uleft ;
fx_v = vleft ;
fx_du_dx = du_dx ;
fx_dv_dx = dv_dx ;
fx_y = y ;
fx_xright = f2i ( xright ) ;
fx_xleft = f2i ( xleft ) ;
pixptr = srcb - > bm_data ;
switch ( Lighting_enabled ) {
case 0 :
//added 07/11/99 adb - prevent writing before the buffer
if ( fx_xleft < 0 )
fx_xleft = 0 ;
//end addition -adb
cur_tmap_scanline_lin_nolight ( ) ;
break ;
case 1 :
if ( lleft < F1_0 / 2 )
lleft = F1_0 / 2 ;
if ( lright < F1_0 / 2 )
lright = F1_0 / 2 ;
if ( lleft > MAX_LIGHTING_VALUE * NUM_LIGHTING_LEVELS )
lleft = MAX_LIGHTING_VALUE * NUM_LIGHTING_LEVELS ;
if ( lright > MAX_LIGHTING_VALUE * NUM_LIGHTING_LEVELS )
lright = MAX_LIGHTING_VALUE * NUM_LIGHTING_LEVELS ;
//added 07/11/99 adb - prevent writing before the buffer
if ( fx_xleft < 0 )
fx_xleft = 0 ;
//end addition -adb
{
fix mul_thing ;
fx_l = lleft ;
fx_dl_dx = fixmul ( lright - lleft , recip_dx ) ;
// This is a pretty ugly hack to prevent lighting overflows.
mul_thing = dx * fx_dl_dx ;
if ( lleft + mul_thing < 0 )
fx_dl_dx + = 12 ;
else if ( lleft + mul_thing > ( NUM_LIGHTING_LEVELS * F1_0 - F1_0 / 2 ) )
fx_dl_dx - = 12 ;
}
fx_l = lleft ;
dl_dx = fixmul ( lright - lleft , recip_dx ) ;
fx_dl_dx = dl_dx ;
cur_tmap_scanline_lin ( ) ;
break ;
case 2 :
# ifdef EDITOR_TMAP
fx_xright = f2i ( xright ) ;
fx_xleft = f2i ( xleft ) ;
tmap_flat_color = 1 ;
cur_tmap_scanline_flat ( ) ;
# else
Int3 ( ) ; // Illegal, called an editor only routine!
# endif
break ;
}
}
// -------------------------------------------------------------------------------------
// Render a texture map with lighting using perspective interpolation in inner and outer loops.
// -------------------------------------------------------------------------------------
void ntexture_map_lighted_linear ( grs_bitmap * srcb , g3ds_tmap * t )
{
int vlt , vrt , vlb , vrb ; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
int topy , boty , y , dy ;
fix dx_dy_left , dx_dy_right ;
fix du_dy_left , du_dy_right ;
fix dv_dy_left , dv_dy_right ;
fix dl_dy_left , dl_dy_right ;
int max_y_vertex ;
fix xleft , xright , uleft , vleft , uright , vright , lleft , lright ;
int next_break_left , next_break_right ;
fix recip_dyl , recip_dyr ;
g3ds_vertex * v3d ;
//remove stupid warnings in compile
dl_dy_left = F1_0 ;
dl_dy_right = F1_0 ;
lleft = F1_0 ;
lright = F1_0 ;
v3d = t - > verts ;
// Determine top and bottom y coords.
compute_y_bounds ( t , & vlt , & vlb , & vrt , & vrb , & max_y_vertex ) ;
// Set top and bottom (of entire texture map) y coordinates.
topy = f2i ( v3d [ vlt ] . y2d ) ;
boty = f2i ( v3d [ max_y_vertex ] . y2d ) ;
if ( topy > Window_clip_bot )
return ;
if ( boty > Window_clip_bot )
boty = Window_clip_bot ;
dy = f2i ( t - > verts [ vlb ] . y2d ) - f2i ( t - > verts [ vlt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dyl = fix_recip [ dy ] ;
else
recip_dyl = F1_0 / dy ;
dy = f2i ( t - > verts [ vrb ] . y2d ) - f2i ( t - > verts [ vrt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dyr = fix_recip [ dy ] ;
else
recip_dyr = F1_0 / dy ;
// Set amount to change x coordinate for each advance to next scanline.
dx_dy_left = compute_dx_dy ( t , vlt , vlb , recip_dyl ) ;
dx_dy_right = compute_dx_dy ( t , vrt , vrb , recip_dyr ) ;
du_dy_left = compute_du_dy_lin ( t , vlt , vlb , recip_dyl ) ;
du_dy_right = compute_du_dy_lin ( t , vrt , vrb , recip_dyr ) ;
dv_dy_left = compute_dv_dy_lin ( t , vlt , vlb , recip_dyl ) ;
dv_dy_right = compute_dv_dy_lin ( t , vrt , vrb , recip_dyr ) ;
if ( Lighting_enabled ) {
dl_dy_left = compute_dl_dy_lin ( t , vlt , vlb , recip_dyl ) ;
dl_dy_right = compute_dl_dy_lin ( t , vrt , vrb , recip_dyr ) ;
lleft = v3d [ vlt ] . l ;
lright = v3d [ vrt ] . l ;
}
// Set initial values for x, u, v
xleft = v3d [ vlt ] . x2d ;
xright = v3d [ vrt ] . x2d ;
uleft = v3d [ vlt ] . u ;
uright = v3d [ vrt ] . u ;
vleft = v3d [ vlt ] . v ;
vright = v3d [ vrt ] . v ;
// scan all rows in texture map from top through first break.
next_break_left = f2i ( v3d [ vlb ] . y2d ) ;
next_break_right = f2i ( v3d [ vrb ] . y2d ) ;
for ( y = topy ; y < boty ; y + + ) {
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x,u,v
if ( y = = next_break_left ) {
fix recip_dy ;
// Handle problem of double points. Search until y coord is different. Cannot get
// hung in an infinite loop because we know there is a vertex with a lower y coordinate
// because in the for loop, we don't scan all spanlines.
while ( y = = f2i ( v3d [ vlb ] . y2d ) ) {
vlt = vlb ;
vlb = prevmod ( vlb , t - > nv ) ;
}
next_break_left = f2i ( v3d [ vlb ] . y2d ) ;
dy = f2i ( t - > verts [ vlb ] . y2d ) - f2i ( t - > verts [ vlt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dy = fix_recip [ dy ] ;
else
recip_dy = F1_0 / dy ;
dx_dy_left = compute_dx_dy ( t , vlt , vlb , recip_dy ) ;
xleft = v3d [ vlt ] . x2d ;
uleft = v3d [ vlt ] . u ;
vleft = v3d [ vlt ] . v ;
lleft = v3d [ vlt ] . l ;
du_dy_left = compute_du_dy_lin ( t , vlt , vlb , recip_dy ) ;
dv_dy_left = compute_dv_dy_lin ( t , vlt , vlb , recip_dy ) ;
if ( Lighting_enabled ) {
dl_dy_left = compute_dl_dy_lin ( t , vlt , vlb , recip_dy ) ;
lleft = v3d [ vlt ] . l ;
}
}
// See if we have reached the end of the current left edge, and if so, set
// new values for dx_dy and x. Not necessary to set new values for u,v.
if ( y = = next_break_right ) {
fix recip_dy ;
while ( y = = f2i ( v3d [ vrb ] . y2d ) ) {
vrt = vrb ;
vrb = succmod ( vrb , t - > nv ) ;
}
dy = f2i ( t - > verts [ vrb ] . y2d ) - f2i ( t - > verts [ vrt ] . y2d ) ;
if ( dy < FIX_RECIP_TABLE_SIZE )
recip_dy = fix_recip [ dy ] ;
else
recip_dy = F1_0 / dy ;
next_break_right = f2i ( v3d [ vrb ] . y2d ) ;
dx_dy_right = compute_dx_dy ( t , vrt , vrb , recip_dy ) ;
xright = v3d [ vrt ] . x2d ;
uright = v3d [ vrt ] . u ;
vright = v3d [ vrt ] . v ;
du_dy_right = compute_du_dy_lin ( t , vrt , vrb , recip_dy ) ;
dv_dy_right = compute_dv_dy_lin ( t , vrt , vrb , recip_dy ) ;
if ( Lighting_enabled ) {
dl_dy_right = compute_dl_dy_lin ( t , vrt , vrb , recip_dy ) ;
lright = v3d [ vrt ] . l ;
}
}
if ( Lighting_enabled ) {
ntmap_scanline_lighted_linear ( srcb , y , xleft , xright , uleft , uright , vleft , vright , lleft , lright ) ;
lleft + = dl_dy_left ;
lright + = dl_dy_right ;
} else
ntmap_scanline_lighted_linear ( srcb , y , xleft , xright , uleft , uright , vleft , vright , lleft , lright ) ;
uleft + = du_dy_left ;
vleft + = dv_dy_left ;
uright + = du_dy_right ;
vright + = dv_dy_right ;
xleft + = dx_dy_left ;
xright + = dx_dy_right ;
}
// We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
// but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
ntmap_scanline_lighted_linear ( srcb , y , xleft , xright , uleft , uright , vleft , vright , lleft , lright ) ;
}
// fix DivNum = F1_0*12;
extern void draw_tmap_flat ( grs_bitmap * bp , int nverts , g3s_point * * vertbuf ) ;
// -------------------------------------------------------------------------------------
// Interface from Matt's data structures to Mike's texture mapper.
// -------------------------------------------------------------------------------------
void draw_tmap ( grs_bitmap * bp , int nverts , g3s_point * * vertbuf )
{
int i ;
// These variables are used in system which renders texture maps which lie on one scanline as a line.
// fix div_numerator;
int lighting_on_save = Lighting_on ;
Assert ( nverts < = MAX_TMAP_VERTS ) ;
# ifdef USE_MULT_CODE
if ( ! divide_table_filled ) fill_divide_table ( ) ;
# endif
// -- now called from g3_start_frame -- init_interface_vars_to_assembler();
// If no transparency and seg depth is large, render as flat shaded.
if ( ( Current_seg_depth > Max_linear_depth ) & & ( ( bp - > bm_flags & 3 ) = = 0 ) ) {
draw_tmap_flat ( bp , nverts , vertbuf ) ;
return ;
}
if ( bp - > bm_flags & BM_FLAG_RLE )
bp = rle_expand_texture ( bp ) ; // Expand if rle'd
Transparency_on = bp - > bm_flags & BM_FLAG_TRANSPARENT ;
if ( bp - > bm_flags & BM_FLAG_NO_LIGHTING )
Lighting_on = 0 ;
// Setup texture map in Tmap1
Tmap1 . nv = nverts ; // Initialize number of vertices
// div_numerator = DivNum; //f1_0*3;
for ( i = 0 ; i < nverts ; i + + ) {
g3ds_vertex * tvp = & Tmap1 . verts [ i ] ;
g3s_point * vp = vertbuf [ i ] ;
tvp - > x2d = vp - > p3_sx ;
tvp - > y2d = vp - > p3_sy ;
// Check for overflow on fixdiv. Will overflow on vp->z <= something small. Allow only as low as 256.
if ( vp - > p3_z < 256 ) {
vp - > p3_z = 256 ;
// Int3(); // we would overflow if we divided!
}
tvp - > z = fixdiv ( F1_0 * 12 , vp - > p3_z ) ;
tvp - > u = vp - > p3_u < < 6 ; //* bp->bm_w;
tvp - > v = vp - > p3_v < < 6 ; //* bp->bm_h;
Assert ( Lighting_on < 3 ) ;
if ( Lighting_on )
tvp - > l = vp - > p3_l * NUM_LIGHTING_LEVELS ;
}
Lighting_enabled = Lighting_on ;
// Now, call my texture mapper.
if ( Lighting_on ) {
switch ( Interpolation_method ) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
case 0 : // choose best interpolation
per2_flag = 1 ;
if ( Current_seg_depth > Max_perspective_depth )
ntexture_map_lighted_linear ( bp , & Tmap1 ) ;
else
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
case 1 : // linear interpolation
per2_flag = 1 ;
ntexture_map_lighted_linear ( bp , & Tmap1 ) ;
break ;
case 2 : // perspective every 8th pixel interpolation
per2_flag = 1 ;
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
case 3 : // perspective every pixel interpolation
per2_flag = 0 ; // this hack means do divide every pixel
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
default :
Assert ( 0 ) ; // Illegal value for Interpolation_method, must be 0,1,2,3
}
} else {
switch ( Interpolation_method ) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
case 0 : // choose best interpolation
per2_flag = 1 ;
if ( Current_seg_depth > Max_perspective_depth )
ntexture_map_lighted_linear ( bp , & Tmap1 ) ;
else
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
case 1 : // linear interpolation
per2_flag = 1 ;
ntexture_map_lighted_linear ( bp , & Tmap1 ) ;
break ;
case 2 : // perspective every 8th pixel interpolation
per2_flag = 1 ;
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
case 3 : // perspective every pixel interpolation
per2_flag = 0 ; // this hack means do divide every pixel
ntexture_map_lighted ( bp , & Tmap1 ) ;
break ;
default :
Assert ( 0 ) ; // Illegal value for Interpolation_method, must be 0,1,2,3
}
}
Lighting_on = lighting_on_save ;
}