tumble / annotate

bitblt.c@8ca2aaf0513f (annotated)

bitblt.c

Thu, 27 Dec 2001 11:04:43 +0000

author
eric
date
Thu, 27 Dec 2001 11:04:43 +0000
changeset 2
8ca2aaf0513f
child 3
317de52d8a63
permissions
-rw-r--r--

Initial revision

eric@2 1 #include <stdlib.h>
eric@2 2
eric@2 3 #include "bitblt.h"
eric@2 4
eric@2 5 static inline u8 pixel_mask (x)
eric@2 6 {
eric@2 7 #ifdef LSB_LEFT
eric@2 8 return (1 << x);
eric@2 9 #else
eric@2 10 return (1 << (7 - x));
eric@2 11 #endif
eric@2 12 }
eric@2 13
eric@2 14 static inline u32 rect_width (Rect r)
eric@2 15 {
eric@2 16 return (r.lower_right.x - r.upper_left.x);
eric@2 17 }
eric@2 18
eric@2 19 static inline u32 rect_height (Rect r)
eric@2 20 {
eric@2 21 return (r.lower_right.y - r.upper_left.y);
eric@2 22 }
eric@2 23
eric@2 24 Bitmap *create_bitmap (u32 width, u32 height)
eric@2 25 {
eric@2 26 Bitmap *bitmap;
eric@2 27
eric@2 28 bitmap = calloc (1, sizeof (Bitmap));
eric@2 29 if (! bitmap)
eric@2 30 return (NULL);
eric@2 31 bitmap->width = width;
eric@2 32 bitmap->height = height;
eric@2 33 bitmap->rowbytes = (width - 1) / 8 + 1;
eric@2 34 bitmap->bits = calloc (height * bitmap->rowbytes, 1);
eric@2 35 if (! bitmap->bits)
eric@2 36 {
eric@2 37 free (bitmap);
eric@2 38 return (NULL);
eric@2 39 }
eric@2 40 return (bitmap);
eric@2 41 }
eric@2 42
eric@2 43 void free_bitmap (Bitmap *bitmap)
eric@2 44 {
eric@2 45 free (bitmap->bits);
eric@2 46 free (bitmap);
eric@2 47 }
eric@2 48
eric@2 49 boolean get_pixel (Bitmap *bitmap, Point coord)
eric@2 50 {
eric@2 51 u8 *p;
eric@2 52 if ((coord.x >= bitmap->width) || (coord.y >= bitmap->height))
eric@2 53 return (0);
eric@2 54 p = bitmap->bits + coord.y * bitmap->rowbytes + coord.x / 8;
eric@2 55 return ((*p & pixel_mask (coord.x & 7)) != 0);
eric@2 56 }
eric@2 57
eric@2 58 void set_pixel (Bitmap *bitmap, Point coord, boolean value)
eric@2 59 {
eric@2 60 u8 *p;
eric@2 61 if ((coord.x >= bitmap->width) || (coord.y >= bitmap->height))
eric@2 62 return;
eric@2 63 p = bitmap->bits + coord.y * bitmap->rowbytes + coord.x / 8;
eric@2 64 if (value)
eric@2 65 *p |= pixel_mask (coord.x & 7);
eric@2 66 else
eric@2 67 *p &= (0xff ^ pixel_mask (coord.x & 7));
eric@2 68 }
eric@2 69
eric@2 70
eric@2 71 Bitmap *bitblt (Bitmap *src_bitmap,
eric@2 72 Rect src_rect,
eric@2 73 Bitmap *dest_bitmap,
eric@2 74 Point dest_upper_left,
eric@2 75 boolean flip_horizontal,
eric@2 76 boolean flip_vertical,
eric@2 77 boolean transpose,
eric@2 78 int tfn)
eric@2 79 {
eric@2 80 Point src_point, dest_point;
eric@2 81 boolean src_pixel, dest_pixel;
eric@2 82
eric@2 83 if (! dest_bitmap)
eric@2 84 {
eric@2 85 if (transpose)
eric@2 86 dest_bitmap = create_bitmap (rect_height (src_rect),
eric@2 87 rect_width (src_rect));
eric@2 88 else
eric@2 89 dest_bitmap = create_bitmap (rect_width (src_rect),
eric@2 90 rect_height (src_rect));
eric@2 91 if (! dest_bitmap)
eric@2 92 return (NULL);
eric@2 93 }
eric@2 94
eric@2 95 for (src_point.y = src_rect.upper_left.y;
eric@2 96 src_point.y < src_rect.lower_right.y;
eric@2 97 src_point.y++)
eric@2 98 {
eric@2 99 for (src_point.x = src_rect.upper_left.x;
eric@2 100 src_point.x < src_rect.lower_right.x;
eric@2 101 src_point.x++)
eric@2 102 {
eric@2 103 boolean a, b, c;
eric@2 104
eric@2 105 if (transpose)
eric@2 106 {
eric@2 107 dest_point.x = dest_upper_left.x + (src_point.y - src_rect.upper_left.y);
eric@2 108 dest_point.y = dest_upper_left.y + (src_point.x - src_rect.upper_left.x);
eric@2 109 }
eric@2 110 else
eric@2 111 {
eric@2 112 dest_point.x = dest_upper_left.x + (src_point.x - src_rect.upper_left.x);
eric@2 113 dest_point.y = dest_upper_left.y + (src_point.y - src_rect.upper_left.y);
eric@2 114 }
eric@2 115
eric@2 116 a = get_pixel (src_bitmap, src_point);
eric@2 117 b = get_pixel (dest_bitmap, dest_point);
eric@2 118 c = (tfn & (1 << (a * 2 + b))) != 0;
eric@2 119
eric@2 120 set_pixel (dest_bitmap, dest_point, c);
eric@2 121 }
eric@2 122 }
eric@2 123 return (dest_bitmap);
eric@2 124 }