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brouhaha.tumble/bitblt.c
Eric Smith 986047af9b Minor updates.
2017-12-27 11:15:09 -07:00

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/*
* tumble: build a PDF file from image files
*
* bitblt routines
* Copyright 2001, 2002, 2003, 2017 Eric Smith <spacewar@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. Note that permission is
* not granted to redistribute this program under the terms of any
* other version of the General Public License.
*
* 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 should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
*/
#include <stdbool.h>
#include <stdint.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bitblt.h"
#include "bitblt_tables.h"
#define SWAP(type,a,b) do { type temp; temp = a; a = b; b = temp; } while (0)
#define DIV_ROUND_UP(count,pow2) (((count) - 1) / (pow2) + 1)
void reverse_bits (uint8_t *p, int byte_count)
{
while (byte_count--)
{
(*p) = bit_reverse_byte [*p];
p++;
}
}
static word_t bit_reverse_word (word_t d)
{
return (bit_reverse_byte [d >> 24] |
(bit_reverse_byte [(d >> 16) & 0xff] << 8) |
(bit_reverse_byte [(d >> 8) & 0xff] << 16) |
(bit_reverse_byte [d & 0xff] << 24));
}
static void reverse_range_of_bytes (uint8_t *b, uint32_t count)
{
uint8_t *b2 = b + count - 1;
while (b < b2)
{
uint8_t t = bit_reverse_byte [*b];
*b = bit_reverse_byte [*b2];
*b2 = t;
b++;
b2--;
}
if (b == b2)
*b = bit_reverse_byte [*b];
}
static word_t *temp_buffer;
static word_t temp_buffer_size;
static void realloc_temp_buffer (uint32_t size)
{
if (size <= temp_buffer_size)
return;
temp_buffer = realloc (temp_buffer, size);
if (! temp_buffer)
{
fprintf (stderr, "realloc failed in bitblt library\n");
exit (2);
}
temp_buffer_size = size;
}
static inline word_t pixel_mask (int x)
{
#if defined (MIXED_ENDIAN) /* disgusting hack for mixed-endian */
word_t m;
m = 0x80 >> (x & 7);
m <<= (x & 24);
return (m);
#elif defined (LSB_RIGHT)
return (1U << ((BITS_PER_WORD - 1) - x));
#else
return (1U << x);
#endif
};
/* mask for range of bits left..right, inclusive */
static inline word_t pixel_range_mask (int left, int right)
{
word_t m1, m2, val;
/* $$$ one of these cases is wrong! */
#if defined (LSB_RIGHT)
m1 = (~ 0U) >> left;
m2 = (~ 0U) << (BITS_PER_WORD - 1 - right);
#else
m1 = (~ 0U) << left;
m2 = (~ 0U) >> (BITS_PER_WORD - 1 - right);
#endif
val = m1 & m2;
printf ("left %d, right %d, mask %08x\n", left, right, val);
return (val);
};
Bitmap *create_bitmap (Rect *rect)
{
Bitmap *bitmap;
uint32_t width = rect_width (rect);
uint32_t height = rect_height (rect);
if ((width <= 0) || (height <= 0))
return (NULL);
bitmap = calloc (1, sizeof (Bitmap));
if (! bitmap)
return (NULL);
bitmap->rect = * rect;
bitmap->row_words = DIV_ROUND_UP (width, BITS_PER_WORD);
bitmap->bits = calloc (1, height * bitmap->row_words * sizeof (word_t));
if (! bitmap->bits)
{
free (bitmap);
return (NULL);
}
return (bitmap);
}
void free_bitmap (Bitmap *bitmap)
{
free (bitmap->bits);
free (bitmap);
}
bool get_pixel (Bitmap *bitmap, Point coord)
{
word_t *p;
int w,b;
if ((coord.x < bitmap->rect.min.x) ||
(coord.x >= bitmap->rect.max.x) ||
(coord.y < bitmap->rect.min.y) ||
(coord.y >= bitmap->rect.max.y))
return (0);
coord.y -= bitmap->rect.min.y;
coord.x -= bitmap->rect.min.x;
w = coord.x / BITS_PER_WORD;
b = coord.x & (BITS_PER_WORD - 1);
p = bitmap->bits + coord.y * bitmap->row_words + w;
return (((*p) & pixel_mask (b)) != 0);
}
void set_pixel (Bitmap *bitmap, Point coord, bool value)
{
word_t *p;
int w,b;
if ((coord.x < bitmap->rect.min.x) ||
(coord.x >= bitmap->rect.max.x) ||
(coord.y < bitmap->rect.min.y) ||
(coord.y >= bitmap->rect.max.y))
return;
coord.y -= bitmap->rect.min.y;
coord.x -= bitmap->rect.min.x;
w = coord.x / BITS_PER_WORD;
b = coord.x & (BITS_PER_WORD - 1);
p = bitmap->bits + coord.y * bitmap->row_words + w;
if (value)
(*p) |= pixel_mask (b);
else
(*p) &= ~pixel_mask (b);
}
/* modifies rect1 to be the intersection of rect1 and rect2;
returns true if intersection is non-null */
static bool clip_rect (Rect *rect1, Rect *rect2)
{
if (rect1->min.y > rect2->max.y)
goto empty;
if (rect1->min.y < rect2->min.y)
{
if (rect1->max.y < rect2->max.y)
goto empty;
rect1->min.y = rect2->min.y;
}
if (rect1->max.y > rect2->max.y)
rect1->max.y = rect2->max.y;
if (rect1->min.x > rect2->max.x)
goto empty;
if (rect1->min.x < rect2->min.x)
{
if (rect1->max.x < rect2->max.x)
goto empty;
rect1->min.x = rect2->min.x;
}
if (rect1->max.x > rect2->max.x)
rect1->max.x = rect2->max.x;
empty:
rect1->min.x = rect1->min.y =
rect1->max.x = rect1->max.y = 0;
return (0);
}
static void blt_background (Bitmap *dest_bitmap,
Rect dest_rect)
{
uint32_t y;
word_t *rp;
uint32_t left_bit, left_word;
uint32_t right_bit, right_word;
word_t left_mask, right_mask;
int32_t word_count;
/* This function requires a non-null dest rect */
assert (dest_rect.min.x < dest_rect.max.x);
assert (dest_rect.min.y < dest_rect.max.y);
/* and that the rows of the dest rect lie entirely within the dest bitmap */
assert (dest_rect.min.y >= dest_bitmap->rect.min.y);
assert (dest_rect.max.y <= dest_bitmap->rect.max.y);
/* clip the x axis of the dest_rect to the bounds of the dest bitmap */
if (dest_rect.min.x < dest_bitmap->rect.min.x)
dest_rect.min.x = dest_bitmap->rect.min.x;
if (dest_rect.max.x > dest_bitmap->rect.max.x)
dest_rect.max.x = dest_bitmap->rect.max.x;
rp = dest_bitmap->bits +
(dest_rect.min.y - dest_bitmap->rect.min.y) * dest_bitmap->row_words +
(dest_rect.min.x - dest_bitmap->rect.min.x) / BITS_PER_WORD;
left_bit = dest_rect.min.x % BITS_PER_WORD;
left_word = dest_rect.min.x / BITS_PER_WORD;
right_bit = (dest_rect.max.x - 1) % BITS_PER_WORD;
right_word = (dest_rect.max.x - 1) / BITS_PER_WORD;
word_count = right_word + 1 - left_word;
/* special case if entire horizontal range fits in a single word */
if (word_count == 1)
{
left_mask = 0;
right_mask = ~ pixel_range_mask (left_bit, right_bit);
word_count = 0;
}
else
{
if (left_bit)
{
left_mask = ~ pixel_range_mask (left_bit, BITS_PER_WORD - 1);
word_count--;
}
if (right_bit != (BITS_PER_WORD - 1))
{
right_mask = ~ pixel_range_mask (0, right_bit);
word_count--;
}
}
for (y = 0; y < rect_height (& dest_rect); y++)
{
word_t *wp = rp;
/* partial word at left, if any */
if (left_mask)
*(wp++) &= left_mask;
/* use Duff's Device for the full words */
if (word_count)
{
int32_t i = word_count;
switch (i % 8)
{
while (i > 0)
{
*(wp++) = 0;
case 7: *(wp++) = 0;
case 6: *(wp++) = 0;
case 5: *(wp++) = 0;
case 4: *(wp++) = 0;
case 3: *(wp++) = 0;
case 2: *(wp++) = 0;
case 1: *(wp++) = 0;
case 0: i -= 8;
}
}
}
/* partial word at right, if any */
if (right_mask)
*wp &= right_mask;
/* advance to next row */
rp += dest_bitmap->row_words;
}
}
#if 0
static void blt (Bitmap *src_bitmap,
Rect *src_rect,
Bitmap *dest_bitmap,
Rect *dest_rect)
{
int32_t y;
word_t *rp;
/* This function requires a non-null src rect */
assert (dest_rect->min.x < dest_rect->max.x);
assert (dest_rect->min.y < dest_rect->max.y);
/* and a non-null dest rect */
assert (dest_rect->min.x < dest_rect->max.x);
assert (dest_rect->min.y < dest_rect->max.y);
/* and that the widths and heights of the rects match */
assert (rect_width (src_rect) == rect_width (dest_rect));
assert (rect_height (src_rect) == rect_height (dest_rect));
/* and that the rows of the src rect lie entirely within the src bitmap */
assert (dest_rect->min.y >= dest_bitmap->rect->min.y);
assert (dest_rect->max.y <= dest_bitmap->rect->max.y);
/* and that the rows of the dest rect lie entirely within the dest bitmap */
assert (dest_rect->min.y >= dest_bitmap->rect->min.y);
assert (dest_rect->max.y <= dest_bitmap->rect->max.y);
/* clip the x axis of the dest_rect to the bounds of the dest bitmap,
and adjust the src_rect to match */
if (dest_rect->min.x < dest_bitmap->rect.min.x)
{
src_rect->min.x += ???;
dest_rect->min.x = dest_bitmap->rect.min.x;
}
if (dest_rect->max.x > dest_bitmap->rect.max.x)
{
dest_rect->max.x = dest_bitmap->rect.max.x;
}
rp = ???;
for (y = 0; y < rect_height (dest_rect); y++)
{
???;
rp += dest_bitmap->row_words;
}
}
/*
* The destination rectangle is first clipped to the dest bitmap, and
* the source rectangle is adjusted in the corresponding manner.
* What's left is divided into five sections, any of which may be
* null. The portion that actually corresponds to the intersection of
* the source rectangle and the source bitmpa is the "middle". The
* other four sections will use the background color as the source
* operand.
*
*
* y0 -> -------------------------------------------------
* | top |
* | |
* y1 -> -------------------------------------------------
* | left | middle | right |
* | | | |
* y2 -> -------------------------------------------------
* | bottom |
* | |
* y3 -> -------------------------------------------------
*
* ^ ^ ^ ^
* | | | |
* x0 x1 x2 x3
*
* */
Bitmap *bitblt (Bitmap *src_bitmap,
Rect *src_rect,
Bitmap *dest_bitmap,
Point *dest_min,
int tfn,
int background)
{
Rect sr, dr; /* src and dest rects, clipped to visible portion of
dest rect */
uint32_t drw, drh; /* dest rect width, height - gets adjusted */
Point src_point, dest_point;
/* dest coordinates: */
uint32_t x0, x1, x2, x3;
uint32_t y0, y1, y2, y3;
{
sr = * src_rect;
uint32_t srw = rect_width (& sr);
uint32_t srh = rect_height (& sr);
if ((srw < 0) || (srh < 0))
goto done; /* the source rect is empty! */
dr.min.x = dest_min->x;
dr.min.y = dest_min->y;
dr.max.x = dr.min.x + srw;
dr.max.y = dr.min.y + srh;
}
if (! dest_bitmap)
{
dest_bitmap = create_bitmap (& dr);
if (! dest_bitmap)
return (NULL);
}
if ((dr.min.x >= dest_bitmap->rect.max.x) ||
(dr.min.y >= dest_bitmap->rect.max.y))
goto done; /* the dest rect isn't even in the dest bitmap! */
/* crop dest rect to dest bitmap */
delta = dest_bitmap->rect.min.x - dr.min.x;
if (delta > 0)
{
sr.min.x += delta;
dr.min.x += delta;
}
delta = dest_bitmap->rect.min.y - dr.min.y;
if (delta > 0)
{
sr.min.y += delta;
dr.min.y += delta;
}
delta = dr.max.x - dest_bitmap->rect.max.x;
if (delta > 0)
{
sr.max.x -= delta;
dr.max.x -= delta;
}
delta = dr.max.y - dest_bitmap->rect.max.y;
if (delta > 0)
{
sr.max.x -= delta;
dr.max.x -= delta;
}
drw = rect_width (& dr);
drh = rect_height (& dh);
x0 = dr.min.x;
y0 = dr.min.y;
x3 = dr.max.x;
y3 = dr.max.y;
#if 0
/* if the source rect min y is >= the source bitmap max y,
we transfer background color to the entire dest rect */
if (sr.min.y >= src->rect.max.y)
{
blt_background (dest_bitmap, dr);
goto done;
}
#endif
/* top */
if (y0 != y1)
{
dr2.min.x = x0;
dr2.max.x = x3;
dr2.min.y = y0;
dr2.max.y = y1;
blt_background (dest_bitmap, & dr2);
}
/*
* top: if the source rect min y is less than the source bitmap min y,
* we need to transfer some backgound color to the top part of the dest
* rect
*/
if (sr.min.y < src->rect.min.y)
{
Rect dr2;
uint32 bg_height;
bg_height = src->rect.min.y - sr.min.y;
if (bg_height > sh)
bg_height = sh;
dr2 = dr;
dr2.max.y = dr2.min.y + bg_height;
blt_background (dest_bitmap, & dr2);
/* now reduce the rect height by the number of lines of background
color */
sr.min.y += bg_height;
dr.min.y += bg_height;
sh -= bg_height;
dh -= bg_height;
if (sr.min.y == sr.max.y)
goto done;
}
if (y1 != y2)
{
/* left */
if (x0 != x1)
{
dr2.min.x = x1;
dr2.max.x = x1;
dr2.min.y = y1;
dr2.max.y = y2
blt_background (dest_bitmap, & dr2);
}
/* middle */
if (x1 != x2)
{
/* ??? */
}
/* right */
if (x2 != x3)
{
dr2.min.x = x2;
dr2.max.x = x3;
dr2.min.y = y1;
dr2.max.y = y2
blt_background (dest_bitmap, & dr2);
}
}
/* bottom */
if (y2 != y3)
{
dr2.min.x = x0;
dr2.max.x = x3;
dr2.min.y = y2;
dr2.max.y = y3;
blt_background (dest_bitmap, & dr2);
}
done:
return (dest_bitmap);
}
#else
Bitmap *bitblt (Bitmap *src_bitmap,
Rect *src_rect,
Bitmap *dest_bitmap,
Point *dest_min,
int tfn,
int background)
{
Point src_point, dest_point;
if (! dest_bitmap)
{
Rect dest_rect = {{ 0, 0 }, { dest_min->x + rect_width (src_rect),
dest_min->y + rect_height (src_rect) }};
dest_bitmap = create_bitmap (& dest_rect);
if (! dest_bitmap)
return (NULL);
}
if (tfn == TF_SRC)
{
for (src_point.y = src_rect->min.y;
src_point.y < src_rect->max.y;
src_point.y++)
{
dest_point.y = dest_min->y + src_point.y - src_rect->min.y;
for (src_point.x = src_rect->min.x;
src_point.x < src_rect->max.x;
src_point.x++)
{
bool a;
dest_point.x = dest_min->x + src_point.x - src_rect->min.x;
a = get_pixel (src_bitmap, src_point);
set_pixel (dest_bitmap, dest_point, a);
}
}
}
else
{
for (src_point.y = src_rect->min.y;
src_point.y < src_rect->max.y;
src_point.y++)
{
dest_point.y = dest_min->y + src_point.y - src_rect->min.y;
for (src_point.x = src_rect->min.x;
src_point.x < src_rect->max.x;
src_point.x++)
{
bool a, b, c;
dest_point.x = dest_min->x + src_point.x - src_rect->min.x;
a = get_pixel (src_bitmap, src_point);
b = get_pixel (dest_bitmap, dest_point);
c = (tfn & (1 << (a * 2 + b))) != 0;
set_pixel (dest_bitmap, dest_point, c);
}
}
}
return (dest_bitmap);
}
#endif
/* in-place transformations */
void flip_h (Bitmap *src)
{
word_t *rp; /* row pointer */
int32_t y;
int shift1, shift2;
rp = src->bits;
if ((rect_width (& src->rect) & 7) == 0)
{
for (y = src->rect.min.y; y < src->rect.max.y; y++)
{
reverse_range_of_bytes ((uint8_t *) rp, rect_width (& src->rect) / 8);
rp += src->row_words;
}
return;
}
realloc_temp_buffer ((src->row_words + 1) * sizeof (word_t));
temp_buffer [0] = 0;
shift1 = rect_width (& src->rect) & (BITS_PER_WORD - 1);
shift2 = BITS_PER_WORD - shift1;
for (y = src->rect.min.y; y < src->rect.max.y; y++)
{
word_t d1, d2;
word_t *p1; /* work src ptr */
word_t *p2; /* work dest ptr */
memcpy (temp_buffer + 1, rp, src->row_words * sizeof (word_t));
p1 = temp_buffer + src->row_words;
p2 = rp;
d2 = *(p1--);
while (p1 >= temp_buffer)
{
word_t t;
d1 = *(p1--);
t = (d1 >> shift1) | (d2 << shift2);
*(p2++) = bit_reverse_word (t);
d2 = d1;
}
rp += src->row_words;
}
}
void flip_v (Bitmap *src)
{
word_t *p1, *p2;
realloc_temp_buffer (src->row_words * sizeof (word_t));
p1 = src->bits;
p2 = src->bits + src->row_words * (rect_height (& src->rect) - 1);
while (p1 < p2)
{
memcpy (temp_buffer, p1, src->row_words * sizeof (word_t));
memcpy (p1, p2, src->row_words * sizeof (word_t));
memcpy (p2, temp_buffer, src->row_words * sizeof (word_t));
p1 += src->row_words;
p2 -= src->row_words;
}
}
void rot_180 (Bitmap *src) /* combination of flip_h and flip_v */
{
flip_h (src);
flip_v (src);
}
/* "in-place" transformations - will allocate new memory and free old */
// XXX hideously inefficient!
void transpose (Bitmap *src)
{
Rect transposed_rect;
Bitmap *dest;
Point src_coord, dest_coord;
transposed_rect.min.x = src->rect.min.y;
transposed_rect.max.x = src->rect.max.y;
transposed_rect.min.y = src->rect.min.x;
transposed_rect.max.y = src->rect.max.x;
dest = create_bitmap (& transposed_rect);
for (src_coord.y = src->rect.min.y; src_coord.y < src->rect.max.y; src_coord.y++)
{
dest_coord.x = src_coord.y;
for (src_coord.x = src->rect.min.x; src_coord.x < src->rect.max.x; src_coord.x++)
{
dest_coord.y = src_coord.x;
set_pixel(dest, dest_coord, get_pixel(src, src_coord));
}
}
SWAP(Bitmap, *src, *dest);
free_bitmap(dest);
}
void rot_90 (Bitmap *src) /* transpose + flip_h */
{
transpose (src);
flip_h (src);
}
void rot_270 (Bitmap *src) /* transpose + flip_v */
{
transpose (src);
flip_v (src);
}
/* frees original! */
Bitmap *resize_bitmap (Bitmap *src,
int width_pixels,
int height_pixels)
{
Rect src_rect;
Point dest_min;
Bitmap *dest;
src_rect.min.x = (rect_width (& src->rect) - width_pixels) / 2;
src_rect.min.y = (rect_height (& src->rect) - height_pixels) / 2;
src_rect.max.x = src_rect.min.x + width_pixels;
src_rect.max.y = src_rect.min.y + height_pixels;
dest_min.x = 0;
dest_min.y = 0;
dest = bitblt (src, & src_rect, NULL, & dest_min, TF_SRC, 0);
free_bitmap (src);
return (dest);
}
/* "in place" rotation */
void rotate_bitmap (Bitmap *src, int rotation)
{
switch (rotation)
{
case 0: break;
case 90: rot_90 (src); break;
case 180: rot_180 (src); break;
case 270: rot_270 (src); break;
default:
fprintf (stderr, "rotation %d, but must be 0, 90, 180, or 270\n", rotation);
}
}
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