[Linux]数码相框&电子书(一)
[Linux]数码相框&电子书(一)
艾恩凝
2021/7/14
Introduction
项目第一天，主要研究了LCD显示文字，基础不1313了，搞了整整一天，知识点到也就这样了，灵活运用就可以了，几年前搞stm32的时候，现在的屏幕显示字和32的差不多，轻车熟路。其他的没什么好说
Achievement
上面是明白基础知识以后，打上的字
Code
1int fd_fb;
2struct fb_var_screeninfo var; /* Current var */
3struct fb_fix_screeninfo fix; /* Current fix */
4int screen_size;
5unsigned char *fbmem;
6unsigned int line_width;
7unsigned int pixel_width;
8
9int fd_hzk16;
10struct stat hzk_stat;
11unsigned char *hzkmem;
12
13FT_Library library;
14FT_Face face;
15FT_Error error;
16FT_Vector pen;
17FT_GlyphSlot slot;
18FT_Matrix matrix; /* transformation matrix */
19
20double aen_angle;
21
22/* color : 0x00RRGGBB */
23void lcd_put_pixel(int x, int y, unsigned int color)
24{
25 unsigned char *pen_8 = fbmem+y*line_width+x*pixel_width;
26 unsigned short *pen_16;
27 unsigned int *pen_32;
28
29 unsigned int red, green, blue;
30
31 pen_16 = (unsigned short *)pen_8;
32 pen_32 = (unsigned int *)pen_8;
33
34 switch (var.bits_per_pixel)
35 {
36 case 8:
37 {
38 *pen_8 = color;
39 break;
40 }
41 case 16:
42 {
43 /* 565 */
44 red = (color >> 16) & 0xff;
45 green = (color >> 8) & 0xff;
46 blue = (color >> 0) & 0xff;
47 color = ((red >> 3) << 11) | ((green >> 2) << 5) | (blue >> 3);
48 *pen_16 = color;
49 break;
50 }
51 case 32:
52 {
53 *pen_32 = color;
54 break;
55 }
56 default:
57 {
58 printf("can't surport %dbpp\n", var.bits_per_pixel);
59 break;
60 }
61 }
62}
63
64void lcd_put_ascii(int x, int y, unsigned char c)
65{
66 unsigned char *dots = (unsigned char *)&fontdata_8x16[c*16];
67 int i, b;
68 unsigned char byte;
69
70 for (i = 0; i < 16; i++)
71 {
72 byte = dots[i];
73 for (b = 7; b >= 0; b--)
74 {
75 if (byte & (1<<b))
76 {
77 /* show */
78 lcd_put_pixel(x+7-b, y+i, 0xffffff); /* 白 */
79 }
80 else
81 {
82 /* hide */
83 lcd_put_pixel(x+7-b, y+i, 0); /* 黑 */
84 }
85 }
86 }
87}
88
89void lcd_put_chinese(int x, int y, unsigned char *str)
90{
91 unsigned int area = str[0] - 0xA1;
92 unsigned int where = str[1] - 0xA1;
93 unsigned char *dots = hzkmem + (area * 94 + where)*32;
94 unsigned char byte;
95
96 int i, j, b;
97 for (i = 0; i < 16; i++)
98 for (j = 0; j < 2; j++)
99 {
100 byte = dots[i*2 + j];
101 for (b = 7; b >=0; b--)
102 {
103 if (byte & (1<<b))
104 {
105 /* show */
106 lcd_put_pixel(x+j*8+7-b, y+i, 0xffffff); /* 白 */
107 }
108 else
109 {
110 /* hide */
111 lcd_put_pixel(x+j*8+7-b, y+i, 0); /* 黑 */
112 }
113
114 }
115 }
116
117}
118
119
120
121/* Replace this function with something useful. */
122
123void
124draw_bitmap( FT_Bitmap* bitmap,
125 FT_Int x,
126 FT_Int y)
127{
128 FT_Int i, j, p, q;
129 FT_Int x_max = x + bitmap->width;
130 FT_Int y_max = y + bitmap->rows;
131
132 for ( i = x, p = 0; i < x_max; i++, p++ )
133 {
134 for ( j = y, q = 0; j < y_max; j++, q++ )
135 {
136 if ( i < 0 || j < 0 ||
137 i >= var.xres || j >= var.yres )
138 continue;
139
140 //image[j][i] |= bitmap->buffer[q * bitmap->width + p];
141 lcd_put_pixel(i, j, bitmap->buffer[q * bitmap->width + p]);
142 }
143 }
144}
145
146int show_word(__u32 x, __u32 y,char *angle,wchar_t *str){
147 /* 确定座标:
148 * lcd_x = var.xres/2 + 8 + 16
149 * lcd_y = var.yres/2 + 16
150 * 笛卡尔座标系:
151 * x = lcd_x = var.xres/2 + 8 + 16
152 * y = var.yres - lcd_y = var.yres/2 - 16
153 */
154 pen.x = x * 64;
155 pen.y = y * 64;
156
157
158 aen_angle= ( 1.0 * strtoul(angle,NULL,0)/ 360 ) * 3.14159 * 2; /* use 25 degrees */
159 /* set up matrix */
160 matrix.xx = (FT_Fixed)( cos( aen_angle ) * 0x10000L );
161 matrix.xy = (FT_Fixed)(-sin( aen_angle ) * 0x10000L );
162 matrix.yx = (FT_Fixed)( sin( aen_angle ) * 0x10000L );
163 matrix.yy = (FT_Fixed)( cos( aen_angle ) * 0x10000L );
164
165 /* set transformation */
166 FT_Set_Transform( face, &matrix, &pen);
167
168 /* load glyph image into the slot (erase previous one) */
169 error = FT_Load_Char( face, (FT_ULong)str, FT_LOAD_RENDER );
170 if (error)
171 {
172 printf("FT_Load_Char error\n");
173 return -1;
174 }
175
176 draw_bitmap( &slot->bitmap,
177 slot->bitmap_left,
178 var.yres - slot->bitmap_top);
179 return 0;
180
181}
182void show_sentence(__u32 x, __u32 y,int width,int size,char *angle,wchar_t *str){
183 __u32 xx=x;
184 int i = 0;
185 for(i = 0;i < size; i++){
186 show_word(xx, y,angle,(wchar_t *)str[i]);
187 xx = xx + width;
188 }
189
190}
191int main(int argc, char **argv)
192{
193
194 wchar_t *my_blog = L"欢迎访问我的博客：\0";
195 wchar_t *my_address = L"https://aeneag.xyz/";
196
197
198
199 if (argc != 3)
200 {
201 printf("Usage : %s <font_file> <angle>\n", argv[0]);
202 return -1;
203 }
204
205
206 fd_fb = open("/dev/fb0", O_RDWR);
207 if (fd_fb < 0)
208 {
209 printf("can't open /dev/fb0\n");
210 return -1;
211 }
212
213 if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &var))
214 {
215 printf("can't get var\n");
216 return -1;
217 }
218
219 if (ioctl(fd_fb, FBIOGET_FSCREENINFO, &fix))
220 {
221 printf("can't get fix\n");
222 return -1;
223 }
224
225 line_width = var.xres * var.bits_per_pixel / 8;
226 pixel_width = var.bits_per_pixel / 8;
227 screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
228 fbmem = (unsigned char *)mmap(NULL , screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
229 if (fbmem == (unsigned char *)-1)
230 {
231 printf("can't mmap\n");
232 return -1;
233 }
234
235 fd_hzk16 = open("HZK16", O_RDONLY);
236 if (fd_hzk16 < 0)
237 {
238 printf("can't open HZK16\n");
239 return -1;
240 }
241 if(fstat(fd_hzk16, &hzk_stat))
242 {
243 printf("can't get fstat\n");
244 return -1;
245 }
246 hzkmem = (unsigned char *)mmap(NULL , hzk_stat.st_size, PROT_READ, MAP_SHARED, fd_hzk16, 0);
247 if (hzkmem == (unsigned char *)-1)
248 {
249 printf("can't mmap for hzk16\n");
250 return -1;
251 }
252
253 /* clear screen ,black */
254 memset(fbmem, 0, screen_size);
255
256 /* show word */
257 error = FT_Init_FreeType( &library ); /* initialize library */
258 /* error handling omitted */
259
260 error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */
261 /* error handling omitted */
262 slot = face->glyph;
263
264 FT_Set_Pixel_Sizes(face, 24, 0);
265
266 show_sentence(var.xres/2 - 96,var.yres/2 + 24,24,9,argv[2],my_blog);
267 show_sentence(var.xres/2 - 108,var.yres/2 ,12,19,argv[2],my_address);
268#if 0
269 show_word(var.xres/2 - 96, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[0]);
270 show_word(var.xres/2 - 72, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[1]);
271 show_word(var.xres/2 - 48, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[2]);
272 show_word(var.xres/2 - 24, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[3]);
273 show_word(var.xres/2 , var.yres/2 + 24,argv[2],(wchar_t *)my_blog[4]);
274 show_word(var.xres/2 + 24, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[5]);
275 show_word(var.xres/2 + 48, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[6]);
276 show_word(var.xres/2 + 72, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[7]);
277 show_word(var.xres/2 + 96, var.yres/2 + 24,argv[2],(wchar_t *)my_blog[8]);
278
279 show_word(var.xres/2 - 108, var.yres/2 ,argv[2],(wchar_t *)my_address[0]);
280 show_word(var.xres/2 - 96, var.yres/2 ,argv[2],(wchar_t *)my_address[1]);
281 show_word(var.xres/2 - 84, var.yres/2 ,argv[2],(wchar_t *)my_address[2]);
282 show_word(var.xres/2 - 72, var.yres/2 ,argv[2],(wchar_t *)my_address[3]);
283 show_word(var.xres/2 - 60, var.yres/2 ,argv[2],(wchar_t *)my_address[4]);
284 show_word(var.xres/2 - 48, var.yres/2 ,argv[2],(wchar_t *)my_address[5]);
285 show_word(var.xres/2 - 36, var.yres/2 ,argv[2],(wchar_t *)my_address[6]);
286 show_word(var.xres/2 - 24, var.yres/2 ,argv[2],(wchar_t *)my_address[7]);
287 show_word(var.xres/2 - 12, var.yres/2 ,argv[2],(wchar_t *)my_address[8]);
288 show_word(var.xres/2 , var.yres/2 ,argv[2],(wchar_t *)my_address[9]);
289 show_word(var.xres/2 + 12, var.yres/2 ,argv[2],(wchar_t *)my_address[10]);
290 show_word(var.xres/2 + 24, var.yres/2 ,argv[2],(wchar_t *)my_address[11]);
291 show_word(var.xres/2 + 36, var.yres/2 ,argv[2],(wchar_t *)my_address[12]);
292 show_word(var.xres/2 + 48, var.yres/2 ,argv[2],(wchar_t *)my_address[13]);
293 show_word(var.xres/2 + 60, var.yres/2 ,argv[2],(wchar_t *)my_address[14]);
294 show_word(var.xres/2 + 72, var.yres/2 ,argv[2],(wchar_t *)my_address[15]);
295 show_word(var.xres/2 + 84, var.yres/2 ,argv[2],(wchar_t *)my_address[16]);
296 show_word(var.xres/2 + 96, var.yres/2 ,argv[2],(wchar_t *)my_address[17]);
297 show_word(var.xres/2 + 108, var.yres/2 ,argv[2],(wchar_t *)my_address[18]);
298#endif
299
300
301
302 return 0;
303}
代码是这些，有一个警告信息，稍后解决。
警告已解决，优化了代码，代码更新
end
回头看，为什么花了一天时间才搞了这么点东西，自己好菜😭 菜到连个对象都没有。又是流水账的一篇，hhhh
艾恩凝
写于大连
2021/7/14
补充
2021/7/15
显示多行文字，昨天是自己搞的，今天使用了官方例程
code
1#include <sys/mman.h>
2#include <sys/types.h>
3#include <sys/stat.h>
4#include <unistd.h>
5#include <linux/fb.h>
6#include <fcntl.h>
7#include <stdio.h>
8#include <string.h>
9#include <math.h>
10#include <wchar.h>
11
12#include <ft2build.h>
13#include FT_FREETYPE_H
14#include FT_GLYPH_H
15
16typedef struct TGlyph_ {
17 FT_UInt index; /* glyph index */
18 FT_Vector pos; /* glyph origin on the baseline */
19 FT_Glyph image; /* glyph image */
20} TGlyph, *PGlyph;
21
22
23#define MAX_GLYPHS 100
24
25int fd_fb;
26struct fb_var_screeninfo var; /* Current var */
27struct fb_fix_screeninfo fix; /* Current fix */
28int screen_size;
29unsigned char *fbmem;
30unsigned int line_width;
31unsigned int pixel_width;
32
33
34/* color : 0x00RRGGBB */
35void lcd_put_pixel(int x, int y, unsigned int color)
36{
37 unsigned char *pen_8 = fbmem+y*line_width+x*pixel_width;
38 unsigned short *pen_16;
39 unsigned int *pen_32;
40
41 unsigned int red, green, blue;
42
43 pen_16 = (unsigned short *)pen_8;
44 pen_32 = (unsigned int *)pen_8;
45
46 switch (var.bits_per_pixel)
47 {
48 case 8:
49 {
50 *pen_8 = color;
51 break;
52 }
53 case 16:
54 {
55 /* 565 */
56 red = (color >> 16) & 0xff;
57 green = (color >> 8) & 0xff;
58 blue = (color >> 0) & 0xff;
59 color = ((red >> 3) << 11) | ((green >> 2) << 5) | (blue >> 3);
60 *pen_16 = color;
61 break;
62 }
63 case 32:
64 {
65 *pen_32 = color;
66 break;
67 }
68 default:
69 {
70 printf("can't surport %dbpp\n", var.bits_per_pixel);
71 break;
72 }
73 }
74}
75
76
77
78/* Replace this function with something useful. */
79
80void
81draw_bitmap( FT_Bitmap* bitmap,
82 FT_Int x,
83 FT_Int y)
84{
85 FT_Int i, j, p, q;
86 FT_Int x_max = x + bitmap->width;
87 FT_Int y_max = y + bitmap->rows;
88
89 //printf("x = %d, y = %d\n", x, y);
90
91 for ( i = x, p = 0; i < x_max; i++, p++ )
92 {
93 for ( j = y, q = 0; j < y_max; j++, q++ )
94 {
95 if ( i < 0 || j < 0 ||
96 i >= var.xres || j >= var.yres )
97 continue;
98
99 //image[j][i] |= bitmap->buffer[q * bitmap->width + p];
100 lcd_put_pixel(i, j, bitmap->buffer[q * bitmap->width + p]);
101 }
102 }
103}
104
105
106int Get_Glyphs_Frm_Wstr(FT_Face face, wchar_t * wstr, TGlyph glyphs[])
107{
108 int n;
109 PGlyph glyph = glyphs;
110 int pen_x = 0;
111 int pen_y = 0;
112 int error;
113 FT_GlyphSlot slot = face->glyph;;
114
115
116 for (n = 0; n < wcslen(wstr); n++)
117 {
118 glyph->index = FT_Get_Char_Index( face, wstr[n]);
119 /* store current pen position */
120 glyph->pos.x = pen_x;
121 glyph->pos.y = pen_y;
122
123 /* load时是把glyph放入插槽face->glyph */
124 error = FT_Load_Glyph(face, glyph->index, FT_LOAD_DEFAULT);
125 if ( error )
126 continue;
127
128 error = FT_Get_Glyph(face->glyph, &glyph->image );
129 if ( error )
130 continue;
131
132 /* translate the glyph image now */
133 /* 这使得glyph->image里含有位置信息 */
134 FT_Glyph_Transform(glyph->image, 0, &glyph->pos );
135
136 pen_x += slot->advance.x; /* 1/64 point */
137
138 /* increment number of glyphs */
139 glyph++;
140 }
141
142 /* count number of glyphs loaded */
143 return (glyph - glyphs);
144}
145
146void compute_string_bbox(TGlyph glyphs[], FT_UInt num_glyphs, FT_BBox *abbox )
147{
148 FT_BBox bbox;
149 int n;
150
151 bbox.xMin = bbox.yMin = 32000;
152 bbox.xMax = bbox.yMax = -32000;
153
154 for ( n = 0; n < num_glyphs; n++ )
155 {
156 FT_BBox glyph_bbox;
157
158 FT_Glyph_Get_CBox(glyphs[n].image, FT_GLYPH_BBOX_TRUNCATE, &glyph_bbox );
159
160 if (glyph_bbox.xMin < bbox.xMin)
161 bbox.xMin = glyph_bbox.xMin;
162
163 if (glyph_bbox.yMin < bbox.yMin)
164 bbox.yMin = glyph_bbox.yMin;
165
166 if (glyph_bbox.xMax > bbox.xMax)
167 bbox.xMax = glyph_bbox.xMax;
168
169 if (glyph_bbox.yMax > bbox.yMax)
170 bbox.yMax = glyph_bbox.yMax;
171 }
172
173 *abbox = bbox;
174}
175
176
177void Draw_Glyphs(TGlyph glyphs[], FT_UInt num_glyphs, FT_Vector pen)
178{
179 int n;
180 int error;
181
182 for (n = 0; n < num_glyphs; n++)
183 {
184 FT_Glyph_Transform(glyphs[n].image, 0, &pen);
185 /* convert glyph image to bitmap (destroy the glyph copy!) */
186 error = FT_Glyph_To_Bitmap(&glyphs[n].image, FT_RENDER_MODE_NORMAL, 0, /* no additional translation */
187 1 ); /* destroy copy in "image" */
188 if ( !error )
189 {
190 FT_BitmapGlyph bit = (FT_BitmapGlyph)glyphs[n].image;
191 draw_bitmap(&bit->bitmap, bit->left, var.yres - bit->top);
192 FT_Done_Glyph(glyphs[n].image );
193 }
194 }
195}
196
197int main(int argc, char **argv)
198{
199 wchar_t *wstr1 = L"欢迎访问我的博客：";
200 wchar_t *wstr2 = L"https://aeneag.xyz/";
201
202 FT_Library library;
203 FT_Face face;
204 int error;
205 FT_Vector pen;
206 FT_GlyphSlot slot;
207 int i;
208 FT_BBox bbox;
209
210 int line_box_ymin = 10000;
211 int line_box_ymax = 0;
212
213 int line_box_width;
214 int line_box_height;
215
216 TGlyph glyphs[MAX_GLYPHS]; /* glyphs table */
217 FT_UInt num_glyphs;
218
219
220 if (argc != 2)
221 {
222 printf("Usage : %s <font_file>\n", argv[0]);
223 return -1;
224 }
225
226
227 fd_fb = open("/dev/fb0", O_RDWR);
228 if (fd_fb < 0)
229 {
230 printf("can't open /dev/fb0\n");
231 return -1;
232 }
233
234 if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &var))
235 {
236 printf("can't get var\n");
237 return -1;
238 }
239
240 if (ioctl(fd_fb, FBIOGET_FSCREENINFO, &fix))
241 {
242 printf("can't get fix\n");
243 return -1;
244 }
245
246 line_width = var.xres * var.bits_per_pixel / 8;
247 pixel_width = var.bits_per_pixel / 8;
248 screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
249 fbmem = (unsigned char *)mmap(NULL , screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
250 if (fbmem == (unsigned char *)-1)
251 {
252 printf("can't mmap\n");
253 return -1;
254 }
255
256 /* 清屏: 全部设为黑色 */
257 memset(fbmem, 0, screen_size);
258
259 /* 显示矢量字体 */
260 error = FT_Init_FreeType( &library ); /* initialize library */
261 /* error handling omitted */
262
263 error = FT_New_Face( library, argv[1], 0, &face ); /* create face object */
264 /* error handling omitted */
265 slot = face->glyph;
266
267 FT_Set_Pixel_Sizes(face, 24, 0);
268
269 /* wstr1 */
270 num_glyphs = Get_Glyphs_Frm_Wstr(face, wstr1, glyphs);
271
272 compute_string_bbox(glyphs, num_glyphs, &bbox);
273 line_box_width = bbox.xMax - bbox.xMin;
274 line_box_height = bbox.yMax - bbox.yMin;
275
276 pen.x = (var.xres - line_box_width)/2 * 64;
277 pen.y = (var.yres - line_box_height)/2 * 64;
278
279 Draw_Glyphs(glyphs, num_glyphs, pen);
280
281 /* wstr2 */
282 num_glyphs = Get_Glyphs_Frm_Wstr(face, wstr2, glyphs);
283
284 compute_string_bbox(glyphs, num_glyphs, &bbox);
285 line_box_width = bbox.xMax - bbox.xMin;
286 line_box_height = bbox.yMax - bbox.yMin;
287
288 pen.x = (var.xres - line_box_width)/2 * 64;
289 pen.y = pen.y - 24 * 64;
290 Draw_Glyphs(glyphs, num_glyphs, pen);
291
292
293 return 0;
294}
end
艾恩凝
更新写法
艾恩凝
写于大连
2021/7/15
catalogue
[Linux]数码相框&电子书系列
吾心信其可行，
则移山填海之难，
终有成功之日！
——孙文
则移山填海之难，
终有成功之日！
——孙文
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