Renesas / AsciiFont

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
AsciiFont - AsciiFont Class Reference

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.

Diff: AsciiFont.cpp

Revision:
0:99222c303e8f
Child:
1:fc1b3db025d6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/AsciiFont.cpp	Tue Sep 27 07:03:20 2016 +0000
@@ -0,0 +1,100 @@
+#include "mbed.h"
+#include "AsciiFont.h"
+#include "ascii.h"
+
+#define FONT_WIDTH           6
+#define FONT_HEIGHT          8
+
+AsciiFont::AsciiFont(uint8_t * p_buf, int width, int height, int stride, int byte_per_pixel, uint32_t const colour) : 
+    p_text_field(p_buf), max_width(width), max_height(height), buf_stride(stride), pixel_num(byte_per_pixel), background_colour(colour) {
+    
+}
+
+void AsciiFont::erase() {
+    erase(background_colour, 0, 0, max_width, max_height);
+}
+
+void AsciiFont::erase(uint32_t const colour) {
+    erase(colour, 0, 0, max_width, max_height);
+}
+
+void AsciiFont::erase(uint32_t const colour, int x, int y, int width, int height) {
+    int idx_base;
+    int wk_idx, i, j ,k;
+
+    background_colour = colour;
+    idx_base = (x * pixel_num) + (buf_stride * y);
+    for (i = 0; i < height; i++) {
+        wk_idx = idx_base + (buf_stride * i);
+        for (j = 0; j < width; j++) {
+            for (k = (pixel_num - 1); k >= 0; k--) {
+                p_text_field[wk_idx++] = (uint8_t)(background_colour >> (8 * k));
+            }
+        }
+    }
+}
+
+int AsciiFont::draw_string(char * str, int x, int y, uint32_t const colour, int font_size, uint16_t const max_char_num) {
+    int char_num = 0;
+
+    if ((str == NULL) || (font_size <= 0)) {
+        return 0;
+    }
+    while ((*str != '\0') && (char_num < max_char_num)) {
+        if (draw_char(*str, x, y, colour, font_size) == false) {
+            break;
+        }
+        str++;
+        x += FONT_WIDTH * font_size;
+        char_num++;
+    }
+    return char_num;
+}
+
+bool AsciiFont::draw_char(char c, int x, int y, uint32_t const colour, int font_size) {
+    int idx_base;
+    int idx_y = 0;
+    int wk_idx, i, j ,k, fw, fh;
+    char * p_pattern;
+    uint8_t mask = 0x80;
+    uint32_t wk_colour;
+
+    if (font_size <= 0) {
+        return false;
+    }
+    if ((x + (FONT_WIDTH * font_size)) >= max_width) {
+        return false;
+    }
+    if ((y + (FONT_HEIGHT * font_size)) >= max_height) {
+        return false;
+    }
+
+    if ((c >= 0x20) && (c <= 0x7e)) {
+        p_pattern = (char *)&ASCII_TABLE[c - 0x20][0];
+    } else {
+        p_pattern = (char *)&ASCII_TABLE[10][0]; /* '*' */
+    }
+    idx_base = (x * pixel_num) + (buf_stride * y);
+
+    /* Drawing */
+    for (i = 0; i < FONT_HEIGHT; i++) {
+        for (fh = 0; fh < font_size; fh++) {
+            wk_idx = idx_base + (buf_stride * idx_y);
+            for (j = 0; j < FONT_WIDTH; j++) {
+                if (p_pattern[j] & mask) {
+                    wk_colour = colour;
+                } else {
+                    wk_colour = background_colour;
+                }
+                for (fw = 0; fw < font_size; fw++) {
+                    for (k = (pixel_num - 1); k >= 0; k--) {
+                        p_text_field[wk_idx++] = (uint8_t)(wk_colour >> (8 * k));
+                    }
+                }
+            }
+            idx_y++;
+        }
+        mask = (uint8_t)(mask >> 1);
+    }
+    return true;
+}