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 #include "vp9/common/vp9_textblit.h"
14
15 static const int font[] = {
16 0x0, 0x5C00, 0x8020, 0xAFABEA, 0xD7EC0, 0x1111111, 0x1855740, 0x18000,
17 0x45C0, 0x74400, 0x51140, 0x23880, 0xC4000, 0x21080, 0x80000, 0x111110,
18 0xE9D72E, 0x87E40, 0x12AD732, 0xAAD62A, 0x4F94C4, 0x4D6B7, 0x456AA,
19 0x3E8423, 0xAAD6AA, 0xAAD6A2, 0x2800, 0x2A00, 0x8A880, 0x52940, 0x22A20,
20 0x15422, 0x6AD62E, 0x1E4A53E, 0xAAD6BF, 0x8C62E, 0xE8C63F, 0x118D6BF,
21 0x1094BF, 0xCAC62E, 0x1F2109F, 0x118FE31, 0xF8C628, 0x8A89F, 0x108421F,
22 0x1F1105F, 0x1F4105F, 0xE8C62E, 0x2294BF, 0x164C62E, 0x12694BF, 0x8AD6A2,
23 0x10FC21, 0x1F8421F, 0x744107, 0xF8220F, 0x1151151, 0x117041, 0x119D731,
24 0x47E0, 0x1041041, 0xFC400, 0x10440, 0x1084210, 0x820
25 };
26
plot(int x,int y,unsigned char * image,int pitch)27 static void plot(int x, int y, unsigned char *image, int pitch) {
28 image[x + y * pitch] ^= 255;
29 }
30
vp9_blit_text(const char * msg,unsigned char * address,const int pitch)31 void vp9_blit_text(const char *msg, unsigned char *address, const int pitch) {
32 int letter_bitmap;
33 unsigned char *output_pos = address;
34 int colpos = 0;
35
36 while (msg[colpos] != 0) {
37 char letter = msg[colpos];
38 int fontcol, fontrow;
39
40 if (letter <= 'Z' && letter >= ' ')
41 letter_bitmap = font[letter - ' '];
42 else if (letter <= 'z' && letter >= 'a')
43 letter_bitmap = font[letter - 'a' + 'A' - ' '];
44 else
45 letter_bitmap = font[0];
46
47 for (fontcol = 6; fontcol >= 0; fontcol--)
48 for (fontrow = 0; fontrow < 5; fontrow++)
49 output_pos[fontrow * pitch + fontcol] =
50 ((letter_bitmap >> (fontcol * 5)) & (1 << fontrow) ? 255 : 0);
51
52 output_pos += 7;
53 colpos++;
54 }
55 }
56
57
58
59 /* Bresenham line algorithm */
vp9_blit_line(int x0,int x1,int y0,int y1,unsigned char * image,int pitch)60 void vp9_blit_line(int x0, int x1, int y0, int y1, unsigned char *image,
61 int pitch) {
62 int steep = abs(y1 - y0) > abs(x1 - x0);
63 int deltax, deltay;
64 int error, ystep, y, x;
65
66 if (steep) {
67 int t;
68 t = x0;
69 x0 = y0;
70 y0 = t;
71
72 t = x1;
73 x1 = y1;
74 y1 = t;
75 }
76
77 if (x0 > x1) {
78 int t;
79 t = x0;
80 x0 = x1;
81 x1 = t;
82
83 t = y0;
84 y0 = y1;
85 y1 = t;
86 }
87
88 deltax = x1 - x0;
89 deltay = abs(y1 - y0);
90 error = deltax / 2;
91
92 y = y0;
93
94 if (y0 < y1)
95 ystep = 1;
96 else
97 ystep = -1;
98
99 if (steep) {
100 for (x = x0; x <= x1; x++) {
101 plot(y, x, image, pitch);
102
103 error = error - deltay;
104 if (error < 0) {
105 y = y + ystep;
106 error = error + deltax;
107 }
108 }
109 } else {
110 for (x = x0; x <= x1; x++) {
111 plot(x, y, image, pitch);
112
113 error = error - deltay;
114 if (error < 0) {
115 y = y + ystep;
116 error = error + deltax;
117 }
118 }
119 }
120 }
121