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:
Tue Mar 07 05:04:28 2017 +0000
Revision:
5:1eaa4942db53
Parent:
4:8fb5219bbc09
Added range check to Erase function.

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 AsciiFont::AsciiFont(uint8_t * p_buf, int width, int height, int stride, int byte_per_pixel, uint32_t const colour) :
dkato 0:99222c303e8f 6 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 7
dkato 0:99222c303e8f 8 }
dkato 0:99222c303e8f 9
dkato 2:d0bc8c2974e0 10 void AsciiFont::Erase() {
dkato 2:d0bc8c2974e0 11 Erase(background_colour, 0, 0, max_width, max_height);
dkato 0:99222c303e8f 12 }
dkato 0:99222c303e8f 13
dkato 2:d0bc8c2974e0 14 void AsciiFont::Erase(uint32_t const colour) {
dkato 2:d0bc8c2974e0 15 Erase(colour, 0, 0, max_width, max_height);
dkato 0:99222c303e8f 16 }
dkato 0:99222c303e8f 17
dkato 2:d0bc8c2974e0 18 void AsciiFont::Erase(uint32_t const colour, int x, int y, int width, int height) {
dkato 0:99222c303e8f 19 int idx_base;
dkato 0:99222c303e8f 20 int wk_idx, i, j ,k;
dkato 0:99222c303e8f 21
dkato 0:99222c303e8f 22 background_colour = colour;
dkato 5:1eaa4942db53 23 if ((x + width) > max_width) {
dkato 5:1eaa4942db53 24 width = max_width - x;
dkato 5:1eaa4942db53 25 }
dkato 5:1eaa4942db53 26 if ((y + height) > max_height) {
dkato 5:1eaa4942db53 27 height = max_height - y;
dkato 5:1eaa4942db53 28 }
dkato 0:99222c303e8f 29 idx_base = (x * pixel_num) + (buf_stride * y);
dkato 0:99222c303e8f 30 for (i = 0; i < height; i++) {
dkato 0:99222c303e8f 31 wk_idx = idx_base + (buf_stride * i);
dkato 0:99222c303e8f 32 for (j = 0; j < width; j++) {
dkato 0:99222c303e8f 33 for (k = (pixel_num - 1); k >= 0; k--) {
dkato 0:99222c303e8f 34 p_text_field[wk_idx++] = (uint8_t)(background_colour >> (8 * k));
dkato 0:99222c303e8f 35 }
dkato 0:99222c303e8f 36 }
dkato 0:99222c303e8f 37 }
dkato 0:99222c303e8f 38 }
dkato 0:99222c303e8f 39
dkato 4:8fb5219bbc09 40 int AsciiFont::DrawStr(const char * str, int x, int y, uint32_t const colour, int font_size, uint16_t const max_char_num) {
dkato 0:99222c303e8f 41 int char_num = 0;
dkato 0:99222c303e8f 42
dkato 0:99222c303e8f 43 if ((str == NULL) || (font_size <= 0)) {
dkato 0:99222c303e8f 44 return 0;
dkato 0:99222c303e8f 45 }
dkato 0:99222c303e8f 46 while ((*str != '\0') && (char_num < max_char_num)) {
dkato 2:d0bc8c2974e0 47 if (DrawChar(*str, x, y, colour, font_size) == false) {
dkato 0:99222c303e8f 48 break;
dkato 0:99222c303e8f 49 }
dkato 0:99222c303e8f 50 str++;
dkato 2:d0bc8c2974e0 51 x += CHAR_PIX_WIDTH * font_size;
dkato 0:99222c303e8f 52 char_num++;
dkato 0:99222c303e8f 53 }
dkato 0:99222c303e8f 54 return char_num;
dkato 0:99222c303e8f 55 }
dkato 0:99222c303e8f 56
dkato 2:d0bc8c2974e0 57 bool AsciiFont::DrawChar(char c, int x, int y, uint32_t const colour, int font_size) {
dkato 0:99222c303e8f 58 int idx_base;
dkato 0:99222c303e8f 59 int idx_y = 0;
dkato 0:99222c303e8f 60 int wk_idx, i, j ,k, fw, fh;
dkato 0:99222c303e8f 61 char * p_pattern;
dkato 0:99222c303e8f 62 uint8_t mask = 0x80;
dkato 0:99222c303e8f 63 uint32_t wk_colour;
dkato 0:99222c303e8f 64
dkato 0:99222c303e8f 65 if (font_size <= 0) {
dkato 0:99222c303e8f 66 return false;
dkato 0:99222c303e8f 67 }
dkato 2:d0bc8c2974e0 68 if ((x + (CHAR_PIX_WIDTH * font_size)) > max_width) {
dkato 0:99222c303e8f 69 return false;
dkato 0:99222c303e8f 70 }
dkato 2:d0bc8c2974e0 71 if ((y + (CHAR_PIX_HEIGHT * font_size)) > max_height) {
dkato 0:99222c303e8f 72 return false;
dkato 0:99222c303e8f 73 }
dkato 0:99222c303e8f 74
dkato 0:99222c303e8f 75 if ((c >= 0x20) && (c <= 0x7e)) {
dkato 1:fc1b3db025d6 76 p_pattern = (char *)&g_ascii_table[c - 0x20][0];
dkato 0:99222c303e8f 77 } else {
dkato 1:fc1b3db025d6 78 p_pattern = (char *)&g_ascii_table[10][0]; /* '*' */
dkato 0:99222c303e8f 79 }
dkato 0:99222c303e8f 80 idx_base = (x * pixel_num) + (buf_stride * y);
dkato 0:99222c303e8f 81
dkato 0:99222c303e8f 82 /* Drawing */
dkato 2:d0bc8c2974e0 83 for (i = 0; i < CHAR_PIX_HEIGHT; i++) {
dkato 0:99222c303e8f 84 for (fh = 0; fh < font_size; fh++) {
dkato 0:99222c303e8f 85 wk_idx = idx_base + (buf_stride * idx_y);
dkato 2:d0bc8c2974e0 86 for (j = 0; j < CHAR_PIX_WIDTH; j++) {
dkato 0:99222c303e8f 87 if (p_pattern[j] & mask) {
dkato 0:99222c303e8f 88 wk_colour = colour;
dkato 0:99222c303e8f 89 } else {
dkato 0:99222c303e8f 90 wk_colour = background_colour;
dkato 0:99222c303e8f 91 }
dkato 0:99222c303e8f 92 for (fw = 0; fw < font_size; fw++) {
dkato 0:99222c303e8f 93 for (k = (pixel_num - 1); k >= 0; k--) {
dkato 0:99222c303e8f 94 p_text_field[wk_idx++] = (uint8_t)(wk_colour >> (8 * k));
dkato 0:99222c303e8f 95 }
dkato 0:99222c303e8f 96 }
dkato 0:99222c303e8f 97 }
dkato 0:99222c303e8f 98 idx_y++;
dkato 0:99222c303e8f 99 }
dkato 0:99222c303e8f 100 mask = (uint8_t)(mask >> 1);
dkato 0:99222c303e8f 101 }
dkato 0:99222c303e8f 102 return true;
dkato 0:99222c303e8f 103 }
dkato 5:1eaa4942db53 104