home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Amiga ACS 1998 #6
/
amigaacscoverdisc1998-061998.iso
/
games
/
descent
/
source
/
2d
/
ibitblt.c
< prev
next >
Wrap
Text File
|
1998-06-08
|
10KB
|
377 lines
/*
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/2d/rcs/ibitblt.c $
* $Revision: 1.6 $
* $Author: john $
* $Date: 1994/11/28 17:07:29 $
*
* Rountines to copy a bitmap on top of another bitmap, but
* only copying to pixels that are transparent.
*
* $Log: ibitblt.c $
* Revision 1.6 1994/11/28 17:07:29 john
* Took out some unused functions in linear.asm, moved
* gr_linear_movsd from linear.asm to bitblt.c, made sure that
* the code in ibiblt.c sets the direction flags before rep movsing.
*
* Revision 1.5 1994/11/18 22:50:22 john
* Changed shorts to ints in parameters.
*
* Revision 1.4 1994/11/09 16:35:16 john
* First version with working RLE bitmaps.
*
* Revision 1.3 1994/10/03 17:18:05 john
* Fixed bug with edi not getting intialized to zero
* in create_mask.
*
* Revision 1.2 1994/05/31 11:10:55 john
* *** empty log message ***
*
* Revision 1.1 1994/05/30 16:08:27 john
* Initial revision
*
*
*/
#pragma off (unreferenced)
static char rcsid[] = "$Id: ibitblt.c 1.6 1994/11/28 17:07:29 john Exp $";
#pragma on (unreferenced)
#include <conio.h>
#include <dos.h>
#include <stdio.h>
#include <stdlib.h>
#include "types.h"
#include "gr.h"
#include "mem.h"
#include "error.h"
#include "ibitblt.h"
#define MODE_NONE 0
#define MODE_SKIP 1
#define MODE_DRAW 2
#define OPCODE_ADD 0x81
#define OPCODE_ESI 0xC6 // Followed by a dword (add esi, ????)
#define OPCODE_EDI 0xC7 // Followed by a dword (add edi, ????)
#define OPCODE_MOV_ECX 0xB9 // Followed by a dword (mov ecx,????)
#define OPCODE_MOVSB 0xA4 // movsb
#define OPCODE_16BIT 0x66 // movsw
#define OPCODE_MOVSD 0xA5 // movsd
#define OPCODE_REP 0xF3 // rep
#define OPCODE_RET 0xC3 // ret
ubyte *Code_pointer = NULL;
int Code_counter = 0;
void move_and_count( int dsource, int ddest, int ecx )
{
int blocks;
if ( ecx <= 0 )
return;
if ( dsource > 0 )
Code_counter+=6; // ADD ESI, dsource
if ( ddest > 0 )
Code_counter+=6; // ADD EDI, ddest
while ( ecx > 0 ) {
switch(ecx) {
case 1: Code_counter++; ecx = 0; break; // MOVSB
case 2: Code_counter+=2; ecx = 0; break; // MOVSW
case 3: Code_counter+=3; ecx = 0; break; // MOVSW, MOVSB
case 4: Code_counter++; ecx = 0; break; // MOVSD
default:
blocks = ecx / 4;
if ( blocks == 1 )
Code_counter++; // MOVSD
else
Code_counter+=7;
ecx -= blocks*4;
}
}
}
void move_and_draw( int dsource, int ddest, int ecx )
{
int blocks;
int * iptr;
if ( ecx <= 0 )
return;
if ( dsource > 0 ) {
// ADD ESI, dsource
*Code_pointer++ = OPCODE_ADD;
*Code_pointer++ = OPCODE_ESI;
iptr = (int *)Code_pointer;
*iptr++ = dsource;
Code_pointer = (ubyte *)iptr;
}
if ( ddest > 0 ) {
// ADD EDI, ddest
*Code_pointer++ = OPCODE_ADD;
*Code_pointer++ = OPCODE_EDI;
iptr = (int *)Code_pointer;
*iptr++ = ddest;
Code_pointer = (ubyte *)iptr;
}
while ( ecx > 0 ) {
switch( ecx ) {
case 1:
// MOVSB
*Code_pointer++ = OPCODE_MOVSB;
ecx = 0;
break;
case 2:
// MOVSW
*Code_pointer++ = OPCODE_16BIT;
*Code_pointer++ = OPCODE_MOVSD;
ecx = 0;
break;
case 3:
// MOVSW, MOVSB
*Code_pointer++ = OPCODE_16BIT;
*Code_pointer++ = OPCODE_MOVSD;
*Code_pointer++ = OPCODE_MOVSB;
ecx = 0;
break;
case 4:
// MOVSD
*Code_pointer++ = OPCODE_MOVSD;
ecx = 0;
break;
default:
blocks = ecx / 4;
if ( blocks == 1 ) {
// MOVSD
*Code_pointer++ = OPCODE_MOVSD;
} else {
// MOV ECX, blocks
*Code_pointer++ = OPCODE_MOV_ECX;
iptr = (int *)Code_pointer;
*iptr++ = blocks;
Code_pointer = (ubyte *)iptr;
// REP MOVSD
*Code_pointer++ = OPCODE_REP;
*Code_pointer++ = OPCODE_MOVSD;
}
ecx -= blocks*4;
}
}
}
//-----------------------------------------------------------------------------------------
// Given bitmap, bmp, finds the size of the code
int gr_ibitblt_find_code_size( grs_bitmap * mask_bmp, int sx, int sy, int sw, int sh, int srowsize )
{
int x,y;
ubyte pixel;
int draw_mode = MODE_NONE;
int source_offset = 0;
int dest_offset = 0;
int num_to_draw, draw_start_source, draw_start_dest;
int esi, edi;
Assert( (!(mask_bmp->bm_flags&BM_FLAG_RLE)) );
Code_counter = 0;
esi = source_offset = 0;
edi = dest_offset = 0;
draw_start_source = draw_start_dest = 0;
for ( y=sy; y<sy+sh; y++ ) {
for ( x=sx; x<sx+sw; x++ ) {
dest_offset = y*mask_bmp->bm_rowsize+x;
pixel = mask_bmp->bm_data[dest_offset];
if ( pixel!=255 ) {
switch ( draw_mode) {
case MODE_DRAW:
move_and_count( draw_start_source-esi, draw_start_dest-edi, num_to_draw );
esi = draw_start_source + num_to_draw;
edi = draw_start_dest + num_to_draw;
// fall through!!!
case MODE_NONE:
case MODE_SKIP:
break;
}
draw_mode = MODE_SKIP;
} else {
switch ( draw_mode) {
case MODE_SKIP:
case MODE_NONE:
draw_start_source = source_offset;
draw_start_dest = dest_offset;
num_to_draw = 0;
// fall through
case MODE_DRAW:
num_to_draw++;
break;
}
draw_mode = MODE_DRAW;
}
source_offset++;
}
if ( draw_mode == MODE_DRAW ) {
move_and_count( draw_start_source-esi, draw_start_dest-edi, num_to_draw );
esi = draw_start_source + num_to_draw;
edi = draw_start_dest + num_to_draw;
}
draw_mode = MODE_NONE;
source_offset += (srowsize - sw);
}
Code_counter++; // for return
//printf( "Code will be %d bytes\n", Code_counter );
Code_counter += 16; // for safety
return Code_counter;
}
//-----------------------------------------------------------------------------------------
// Given bitmap, bmp, create code that transfers a bitmap of size sw*sh to position
// (sx,sy) on top of bmp, only overwritting transparent pixels of the bitmap.
ubyte *gr_ibitblt_create_mask( grs_bitmap * mask_bmp, int sx, int sy, int sw, int sh, int srowsize )
{
int x,y;
ubyte pixel;
int draw_mode = MODE_NONE;
int source_offset = 0;
int dest_offset = 0;
int num_to_draw, draw_start_source, draw_start_dest;
int esi, edi;
int code_size;
ubyte *code;
Assert( (!(mask_bmp->bm_flags&BM_FLAG_RLE)) );
code_size = gr_ibitblt_find_code_size( mask_bmp, sx, sy, sw, sh, srowsize );
code = malloc( code_size );
if ( code == NULL )
return NULL;
Code_pointer = code;
esi = source_offset = 0;
edi = dest_offset = 0;
draw_start_source = draw_start_dest = 0;
for ( y=sy; y<sy+sh; y++ ) {
for ( x=sx; x<sx+sw; x++ ) {
dest_offset = y*mask_bmp->bm_rowsize+x;
pixel = mask_bmp->bm_data[dest_offset];
if ( pixel!=255 ) {
switch ( draw_mode) {
case MODE_DRAW:
move_and_draw( draw_start_source-esi, draw_start_dest-edi, num_to_draw );
esi = draw_start_source + num_to_draw;
edi = draw_start_dest + num_to_draw;
// fall through!!!
case MODE_NONE:
case MODE_SKIP:
break;
}
draw_mode = MODE_SKIP;
} else {
switch ( draw_mode) {
case MODE_SKIP:
case MODE_NONE:
draw_start_source = source_offset;
draw_start_dest = dest_offset;
num_to_draw = 0;
// fall through
case MODE_DRAW:
num_to_draw++;
break;
}
draw_mode = MODE_DRAW;
}
source_offset++;
}
if ( draw_mode == MODE_DRAW ) {
move_and_draw( draw_start_source-esi, draw_start_dest-edi, num_to_draw );
esi = draw_start_source + num_to_draw;
edi = draw_start_dest + num_to_draw;
}
draw_mode = MODE_NONE;
source_offset += (srowsize - sw);
}
*Code_pointer++ = OPCODE_RET;
if ( Code_pointer >= &code[code_size-1] )
Error( "ibitblt overwrote allocated code block\n" );
//printf( "Code is %d bytes\n", Code_pointer - code );
return code;
}
void gr_ibitblt_do_asm(char *start_si, char *start_di, ubyte * code);
#pragma aux gr_ibitblt_do_asm parm [esi] [edi] [eax] modify [ecx edi esi eax] = \
"pusha" \
"cld" \
"call eax" \
"popa"
void gr_ibitblt(grs_bitmap * source_bmp, grs_bitmap * dest_bmp, ubyte * mask )
{
if (mask != NULL )
gr_ibitblt_do_asm( source_bmp->bm_data, dest_bmp->bm_data, mask );
}
void gr_ibitblt_find_hole_size( grs_bitmap * mask_bmp, int *minx, int *miny, int *maxx, int *maxy )
{
ubyte c;
int x, y, count=0;
Assert( (!(mask_bmp->bm_flags&BM_FLAG_RLE)) );
*minx = mask_bmp->bm_w-1;
*maxx = 0;
*miny = mask_bmp->bm_h-1;
*maxy = 0;
for ( y=0; y<mask_bmp->bm_h; y++ )
for ( x=0; x<mask_bmp->bm_w; x++ ) {
c = mask_bmp->bm_data[mask_bmp->bm_rowsize*y+x];
if (c == 255 ) {
if ( x < *minx ) *minx = x;
if ( y < *miny ) *miny = y;
if ( x > *maxx ) *maxx = x;
if ( y > *maxy ) *maxy = y;
count++;
}
}
if ( count == 0 ) {
Error( "Bitmap for ibitblt doesn't have transparency!\n" );
}
}