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/**
** sipp - SImple Polygon Processor
**
** A general 3d graphic package
**
** Copyright Equivalent Software HB 1992
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 1, or any later version.
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
** You can receive a copy of the GNU General Public License from the
** Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**/
/**
** sipp_bitmap.c - A sample bitmap for use in SIPP and routines to use it.
**/
#include <sys/types.h>
#include <stdio.h>
#include <sipp.h>
#include <smalloc.h>
#include <sipp_bitmap.h>
/* ================================================================ */
/*
* Return a pointer to a new Sipp_bitmap, with the size WIDTH x HEIGHT.
* Enough space is allocated so each line ends on a byte boundary.
*/
Sipp_bitmap *
sipp_bitmap_create(width, height)
int width;
int height;
{
Sipp_bitmap * bm;
bm = (Sipp_bitmap *) smalloc(sizeof(Sipp_bitmap));
bm->width = width;
bm->height = height;
bm->width_bytes = (width >> 3);
if ((width & 7) != 0) {
bm->width_bytes++;
}
bm->buffer = (u_char *) scalloc(bm->width_bytes * height, sizeof(u_char));
return bm;
}
/*
* Destruct a bitmap, and free allocated memory.
*/
void
sipp_bitmap_destruct(bm)
Sipp_bitmap * bm;
{
if (bm != NULL) {
if (bm->buffer != NULL) {
sfree(bm->buffer);
}
sfree(bm);
}
}
/*
* Draw a line in the Sipp_bitmap BM from (X1, Y1)
* to (X2, Y2)
*/
#define PLOT(bm, width_bytes, yres, x, y) \
(bm)[(y) * (width_bytes) + ((x) >> 3)] |= (1 << (7 - ((x) & 7)))
void
sipp_bitmap_line(bm, x1, y1, x2, y2)
Sipp_bitmap * bm;
int x1, y1;
int x2, y2;
{
int d;
int x, y;
int ax, ay;
int sx, sy;
int dx, dy;
dx = x2 - x1;
ax = abs(dx) << 1;
sx = ((dx < 0) ? -1 : 1);
dy = y2 - y1;
ay = abs(dy) << 1;
sy = ((dy < 0) ? -1 : 1);
x = x1;
y = y1;
if (ax > ay) {
d = ay - (ax >> 1);
for (;;) {
PLOT(bm->buffer, bm->width_bytes, bm->height, x, y);
if (x == x2) {
return;
}
if (d >= 0) {
y += sy;
d -= ax;
}
x += sx;
d += ay;
}
} else {
d = ax - (ay >> 1);
for (;;) {
PLOT(bm->buffer, bm->width_bytes, bm->height, x, y);
if (y == y2) {
return;
}
if (d >= 0) {
x += sx;
d -= ay;
}
y += sy;
d += ax;
}
}
}
/*
* Write the Sipp_bitmap BM to the open file FILE.
*/
void
sipp_bitmap_write(file, bm)
FILE * file;
Sipp_bitmap * bm;
{
int written;
int wrote;
int left;
fprintf(file, "P4\n");
fprintf(file, "#Image rendered with SIPP %s\n", SIPP_VERSION);
fprintf(file, "%d\n%d\n", bm->width, bm->height);
wrote = 0;
written = 0;
left = bm->width_bytes * bm->height;
while ((wrote = fwrite(bm->buffer + written, 1, left, file)) != left) {
written += wrote;
left -= wrote;
}
}
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