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
15static 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
27static void plot(int x, int y, unsigned char *image, int pitch) {
28  image[x + y * pitch] ^= 255;
29}
30
31void 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 */
60void 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