Draw the character of the ASCII code.

Dependents:   mbed-os_Watson-IoT_ZXing_sample mbed-os_Watson-IoT_ZXing_sample MovPlayer GR-PEACH_HVC-P2_sample_client ... more

Fork of AsciiFont by Daiki Kato

AsciiFont

This is a library to draw the ASCII font characters.

Example

#include "mbed.h"
#include "AsciiFont.h"

#define WIDTH           (12)
#define HEIGHT          (16)
#define BYTE_PER_PIXEL  (1u)
#define STRIDE          (((WIDTH * BYTE_PER_PIXEL) + 7u) & ~7u) //multiple of 8

uint8_t text_field[STRIDE * HEIGHT];

//for debug
void print_text_field() {
    int idx = 0;

    for (int i = 0; i < HEIGHT; i++) {
        for (int j = 0; j < STRIDE; j++) {
            printf("%02x", text_field[idx++]);
        }
        printf("\r\n");
    }
    printf("\r\n");
}

int main() {
    AsciiFont ascii_font(text_field, WIDTH, HEIGHT, STRIDE, BYTE_PER_PIXEL);

    ascii_font.Erase(0xcc);
    ascii_font.DrawStr("AB", 0, 0, 0x11, 1);
    ascii_font.DrawChar('C', AsciiFont::CHAR_PIX_WIDTH,
                        AsciiFont::CHAR_PIX_HEIGHT, 0x22, 1);
    print_text_field(); //debug print

    ascii_font.Erase();
    ascii_font.DrawStr("D", 0, 0, 0xef, 2);
    print_text_field(); //debug print

    ascii_font.Erase(0x11, 6, 0, 6, 8);
    print_text_field(); //debug print
}


API

Import library

Public Member Functions

AsciiFont (uint8_t *p_buf, int width, int height, int stride, int byte_per_pixel, uint32_t const colour=0)
Constructor: Initializes AsciiFont .
void Erase ()
Erase text field.
void Erase (uint32_t const colour)
Erase text field.
void Erase (uint32_t const colour, int x, int y, int width, int height)
Erase text field.
int DrawStr (char *str, int x, int y, uint32_t const colour, int font_size=1, uint16_t const max_char_num=0xffff)
Draw a string.
bool DrawChar (char c, int x, int y, uint32_t const colour, int font_size=1)
Draw a character.

Static Public Attributes

static const int CHAR_PIX_WIDTH = 6
The pixel width of a character.
static const int CHAR_PIX_HEIGHT = 8
The pixel height of a character.
Committer:
dkato
Date:
Mon Oct 03 02:20:49 2016 +0000
Revision:
1:fc1b3db025d6
Parent:
0:99222c303e8f
Child:
2:d0bc8c2974e0
Update ascii.c.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dkato 0:99222c303e8f 1 #include "mbed.h"
dkato 0:99222c303e8f 2 #include "AsciiFont.h"
dkato 0:99222c303e8f 3 #include "ascii.h"
dkato 0:99222c303e8f 4
dkato 0:99222c303e8f 5 #define FONT_WIDTH 6
dkato 0:99222c303e8f 6 #define FONT_HEIGHT 8
dkato 0:99222c303e8f 7
dkato 0:99222c303e8f 8 AsciiFont::AsciiFont(uint8_t * p_buf, int width, int height, int stride, int byte_per_pixel, uint32_t const colour) :
dkato 0:99222c303e8f 9 p_text_field(p_buf), max_width(width), max_height(height), buf_stride(stride), pixel_num(byte_per_pixel), background_colour(colour) {
dkato 0:99222c303e8f 10
dkato 0:99222c303e8f 11 }
dkato 0:99222c303e8f 12
dkato 0:99222c303e8f 13 void AsciiFont::erase() {
dkato 0:99222c303e8f 14 erase(background_colour, 0, 0, max_width, max_height);
dkato 0:99222c303e8f 15 }
dkato 0:99222c303e8f 16
dkato 0:99222c303e8f 17 void AsciiFont::erase(uint32_t const colour) {
dkato 0:99222c303e8f 18 erase(colour, 0, 0, max_width, max_height);
dkato 0:99222c303e8f 19 }
dkato 0:99222c303e8f 20
dkato 0:99222c303e8f 21 void AsciiFont::erase(uint32_t const colour, int x, int y, int width, int height) {
dkato 0:99222c303e8f 22 int idx_base;
dkato 0:99222c303e8f 23 int wk_idx, i, j ,k;
dkato 0:99222c303e8f 24
dkato 0:99222c303e8f 25 background_colour = colour;
dkato 0:99222c303e8f 26 idx_base = (x * pixel_num) + (buf_stride * y);
dkato 0:99222c303e8f 27 for (i = 0; i < height; i++) {
dkato 0:99222c303e8f 28 wk_idx = idx_base + (buf_stride * i);
dkato 0:99222c303e8f 29 for (j = 0; j < width; j++) {
dkato 0:99222c303e8f 30 for (k = (pixel_num - 1); k >= 0; k--) {
dkato 0:99222c303e8f 31 p_text_field[wk_idx++] = (uint8_t)(background_colour >> (8 * k));
dkato 0:99222c303e8f 32 }
dkato 0:99222c303e8f 33 }
dkato 0:99222c303e8f 34 }
dkato 0:99222c303e8f 35 }
dkato 0:99222c303e8f 36
dkato 0:99222c303e8f 37 int AsciiFont::draw_string(char * str, int x, int y, uint32_t const colour, int font_size, uint16_t const max_char_num) {
dkato 0:99222c303e8f 38 int char_num = 0;
dkato 0:99222c303e8f 39
dkato 0:99222c303e8f 40 if ((str == NULL) || (font_size <= 0)) {
dkato 0:99222c303e8f 41 return 0;
dkato 0:99222c303e8f 42 }
dkato 0:99222c303e8f 43 while ((*str != '\0') && (char_num < max_char_num)) {
dkato 0:99222c303e8f 44 if (draw_char(*str, x, y, colour, font_size) == false) {
dkato 0:99222c303e8f 45 break;
dkato 0:99222c303e8f 46 }
dkato 0:99222c303e8f 47 str++;
dkato 0:99222c303e8f 48 x += FONT_WIDTH * font_size;
dkato 0:99222c303e8f 49 char_num++;
dkato 0:99222c303e8f 50 }
dkato 0:99222c303e8f 51 return char_num;
dkato 0:99222c303e8f 52 }
dkato 0:99222c303e8f 53
dkato 0:99222c303e8f 54 bool AsciiFont::draw_char(char c, int x, int y, uint32_t const colour, int font_size) {
dkato 0:99222c303e8f 55 int idx_base;
dkato 0:99222c303e8f 56 int idx_y = 0;
dkato 0:99222c303e8f 57 int wk_idx, i, j ,k, fw, fh;
dkato 0:99222c303e8f 58 char * p_pattern;
dkato 0:99222c303e8f 59 uint8_t mask = 0x80;
dkato 0:99222c303e8f 60 uint32_t wk_colour;
dkato 0:99222c303e8f 61
dkato 0:99222c303e8f 62 if (font_size <= 0) {
dkato 0:99222c303e8f 63 return false;
dkato 0:99222c303e8f 64 }
dkato 0:99222c303e8f 65 if ((x + (FONT_WIDTH * font_size)) >= max_width) {
dkato 0:99222c303e8f 66 return false;
dkato 0:99222c303e8f 67 }
dkato 0:99222c303e8f 68 if ((y + (FONT_HEIGHT * font_size)) >= max_height) {
dkato 0:99222c303e8f 69 return false;
dkato 0:99222c303e8f 70 }
dkato 0:99222c303e8f 71
dkato 0:99222c303e8f 72 if ((c >= 0x20) && (c <= 0x7e)) {
dkato 1:fc1b3db025d6 73 p_pattern = (char *)&g_ascii_table[c - 0x20][0];
dkato 0:99222c303e8f 74 } else {
dkato 1:fc1b3db025d6 75 p_pattern = (char *)&g_ascii_table[10][0]; /* '*' */
dkato 0:99222c303e8f 76 }
dkato 0:99222c303e8f 77 idx_base = (x * pixel_num) + (buf_stride * y);
dkato 0:99222c303e8f 78
dkato 0:99222c303e8f 79 /* Drawing */
dkato 0:99222c303e8f 80 for (i = 0; i < FONT_HEIGHT; i++) {
dkato 0:99222c303e8f 81 for (fh = 0; fh < font_size; fh++) {
dkato 0:99222c303e8f 82 wk_idx = idx_base + (buf_stride * idx_y);
dkato 0:99222c303e8f 83 for (j = 0; j < FONT_WIDTH; j++) {
dkato 0:99222c303e8f 84 if (p_pattern[j] & mask) {
dkato 0:99222c303e8f 85 wk_colour = colour;
dkato 0:99222c303e8f 86 } else {
dkato 0:99222c303e8f 87 wk_colour = background_colour;
dkato 0:99222c303e8f 88 }
dkato 0:99222c303e8f 89 for (fw = 0; fw < font_size; fw++) {
dkato 0:99222c303e8f 90 for (k = (pixel_num - 1); k >= 0; k--) {
dkato 0:99222c303e8f 91 p_text_field[wk_idx++] = (uint8_t)(wk_colour >> (8 * k));
dkato 0:99222c303e8f 92 }
dkato 0:99222c303e8f 93 }
dkato 0:99222c303e8f 94 }
dkato 0:99222c303e8f 95 idx_y++;
dkato 0:99222c303e8f 96 }
dkato 0:99222c303e8f 97 mask = (uint8_t)(mask >> 1);
dkato 0:99222c303e8f 98 }
dkato 0:99222c303e8f 99 return true;
dkato 0:99222c303e8f 100 }