1 /*
2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include <stdlib.h>
12
13
vp8_blit_text(const char * msg,unsigned char * address,const int pitch)14 void vp8_blit_text(const char *msg, unsigned char *address, const int pitch)
15 {
16 int letter_bitmap;
17 unsigned char *output_pos = address;
18 int colpos;
19 const int font[] =
20 {
21 0x0, 0x5C00, 0x8020, 0xAFABEA, 0xD7EC0, 0x1111111, 0x1855740, 0x18000,
22 0x45C0, 0x74400, 0x51140, 0x23880, 0xC4000, 0x21080, 0x80000, 0x111110,
23 0xE9D72E, 0x87E40, 0x12AD732, 0xAAD62A, 0x4F94C4, 0x4D6B7, 0x456AA,
24 0x3E8423, 0xAAD6AA, 0xAAD6A2, 0x2800, 0x2A00, 0x8A880, 0x52940, 0x22A20,
25 0x15422, 0x6AD62E, 0x1E4A53E, 0xAAD6BF, 0x8C62E, 0xE8C63F, 0x118D6BF,
26 0x1094BF, 0xCAC62E, 0x1F2109F, 0x118FE31, 0xF8C628, 0x8A89F, 0x108421F,
27 0x1F1105F, 0x1F4105F, 0xE8C62E, 0x2294BF, 0x164C62E, 0x12694BF, 0x8AD6A2,
28 0x10FC21, 0x1F8421F, 0x744107, 0xF8220F, 0x1151151, 0x117041, 0x119D731,
29 0x47E0, 0x1041041, 0xFC400, 0x10440, 0x1084210, 0x820
30 };
31 colpos = 0;
32
33 while (msg[colpos] != 0)
34 {
35 char letter = msg[colpos];
36 int fontcol, fontrow;
37
38 if (letter <= 'Z' && letter >= ' ')
39 letter_bitmap = font[letter-' '];
40 else if (letter <= 'z' && letter >= 'a')
41 letter_bitmap = font[letter-'a'+'A' - ' '];
42 else
43 letter_bitmap = font[0];
44
45 for (fontcol = 6; fontcol >= 0 ; fontcol--)
46 for (fontrow = 0; fontrow < 5; fontrow++)
47 output_pos[fontrow *pitch + fontcol] =
48 ((letter_bitmap >> (fontcol * 5)) & (1 << fontrow) ? 255 : 0);
49
50 output_pos += 7;
51 colpos++;
52 }
53 }
54
plot(const int x,const int y,unsigned char * image,const int pitch)55 static void plot (const int x, const int y, unsigned char *image, const int pitch)
56 {
57 image [x+y*pitch] ^= 255;
58 }
59
60 /* Bresenham line algorithm */
vp8_blit_line(int x0,int x1,int y0,int y1,unsigned char * image,const int pitch)61 void vp8_blit_line(int x0, int x1, int y0, int y1, unsigned char *image, const int pitch)
62 {
63 int steep = abs(y1 - y0) > abs(x1 - x0);
64 int deltax, deltay;
65 int error, ystep, y, x;
66
67 if (steep)
68 {
69 int t;
70 t = x0;
71 x0 = y0;
72 y0 = t;
73
74 t = x1;
75 x1 = y1;
76 y1 = t;
77 }
78
79 if (x0 > x1)
80 {
81 int t;
82 t = x0;
83 x0 = x1;
84 x1 = t;
85
86 t = y0;
87 y0 = y1;
88 y1 = t;
89 }
90
91 deltax = x1 - x0;
92 deltay = abs(y1 - y0);
93 error = deltax / 2;
94
95 y = y0;
96
97 if (y0 < y1)
98 ystep = 1;
99 else
100 ystep = -1;
101
102 if (steep)
103 {
104 for (x = x0; x <= x1; x++)
105 {
106 plot(y,x, image, pitch);
107
108 error = error - deltay;
109 if (error < 0)
110 {
111 y = y + ystep;
112 error = error + deltax;
113 }
114 }
115 }
116 else
117 {
118 for (x = x0; x <= x1; x++)
119 {
120 plot(x,y, image, pitch);
121
122 error = error - deltay;
123 if (error < 0)
124 {
125 y = y + ystep;
126 error = error + deltax;
127 }
128 }
129 }
130 }
131