AsciiFont.h

00001 /* Copyright (c) 2016 dkato
00002  * SPDX-License-Identifier: Apache-2.0
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 /**************************************************************************//**
00017 * @file          AsciiFont.h
00018 * @brief         AsciiFont API
00019 ******************************************************************************/
00020 
00021 #ifndef ASCII_FONT_H
00022 #define ASCII_FONT_H
00023 
00024 #include "mbed.h"
00025 
00026 /** Draw the character of the ASCII code.
00027  *
00028  * Example
00029  * @code
00030  * #include "mbed.h"
00031  * #include "AsciiFont.h"
00032  * 
00033  * #define WIDTH           (12)
00034  * #define HEIGHT          (16)
00035  * #define BYTE_PER_PIXEL  (1u)
00036  * #define STRIDE          (((WIDTH * BYTE_PER_PIXEL) + 7u) & ~7u) //multiple of 8
00037  * 
00038  * uint8_t text_field[STRIDE * HEIGHT];
00039  * 
00040  * //for debug
00041  * void print_text_field() {
00042  *     int idx = 0;
00043  * 
00044  *     for (int i = 0; i < HEIGHT; i++) {
00045  *         for (int j = 0; j < STRIDE; j++) {
00046  *             printf("%02x", text_field[idx++]);
00047  *         }
00048  *         printf("\r\n");
00049  *     }
00050  *     printf("\r\n");
00051  * }
00052  * 
00053  * int main() {
00054  *     AsciiFont ascii_font(text_field, WIDTH, HEIGHT, STRIDE, BYTE_PER_PIXEL);
00055  * 
00056  *     ascii_font.Erase(0xcc);
00057  *     ascii_font.DrawStr("AB", 0, 0, 0x11, 1);
00058  *     ascii_font.DrawChar('C', AsciiFont::CHAR_PIX_WIDTH,
00059  *                         AsciiFont::CHAR_PIX_HEIGHT, 0x22, 1);
00060  *     print_text_field(); //debug print
00061  * 
00062  *     ascii_font.Erase();
00063  *     ascii_font.DrawStr("D", 0, 0, 0xef, 2);
00064  *     print_text_field(); //debug print
00065  * 
00066  *     ascii_font.Erase(0x11, 6, 0, 6, 8);
00067  *     print_text_field(); //debug print
00068  * }
00069  * @endcode
00070  */
00071 
00072 class AsciiFont {
00073 public:
00074 
00075     /** Constructor: Initializes AsciiFont.
00076      *
00077      * @param p_buf Text field address
00078      * @param width Text field width
00079      * @param height Text field height
00080      * @param stride Buffer stride
00081      * @param colour Background color
00082      * @param byte_per_pixel Byte per pixel
00083      */
00084     AsciiFont(uint8_t * p_buf, int width, int height, int stride, int byte_per_pixel, uint32_t const colour = 0);
00085 
00086     /** Erase text field
00087      *
00088      */
00089     void Erase();
00090 
00091     /** Erase text field
00092      *
00093      * @param colour Background color
00094      */
00095     void Erase(uint32_t const colour);
00096 
00097     /** Erase text field
00098      *
00099      * @param colour Background color
00100      * @param x Erase start position of x coordinate
00101      * @param y Erase start position of y coordinate
00102      * @param width Erase field width
00103      * @param height Erase field height
00104      */
00105     void Erase(uint32_t const colour, int x, int y, int width, int height);
00106 
00107     /** Draw a string
00108      *
00109      * @param str String
00110      * @param x Drawing start position of x coordinate
00111      * @param y Drawing start position of y coordinate
00112      * @param color Font color
00113      * @param font_size Font size (>=1)
00114      * @param max_char_num The maximum number of characters
00115      * @return The drawn number of characters
00116      */
00117     int DrawStr(const char * str, int x, int y, uint32_t const colour, int font_size = 1, uint16_t const max_char_num = 0xffff);
00118 
00119     /** Draw a character
00120      *
00121      * @param x Drawing start position of x coordinate
00122      * @param y Drawing start position of y coordinate
00123      * @param color Font color
00124      * @param font_size Font size (>=1)
00125      * @return true if successfull
00126      */
00127     bool DrawChar(char c, int x, int y, uint32_t const colour, int font_size = 1);
00128 
00129     /** The pixel width of a character. (font_size=1)
00130      *
00131      */
00132     static const int CHAR_PIX_WIDTH  = 6;
00133 
00134     /** The pixel height of a character. (font_size=1)
00135      *
00136      */
00137     static const int CHAR_PIX_HEIGHT = 8;
00138 
00139 private:
00140     uint8_t * p_text_field;
00141     int max_width;
00142     int max_height;
00143     int buf_stride;
00144     int pixel_num;
00145     uint32_t background_colour;
00146 };
00147 #endif