embox

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/**
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 * @file text_overlay.c
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 * @brief Some functions to put text to frame
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 * @author Denis Deryugin <deryugin.denis@gmail.com>
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 * @version
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 * @date 14.12.2017
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 */
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#include <string.h>
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#include <drivers/video/fb.h>
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#include <drivers/video/font.h>
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static struct fb_info *text_fb = 0;
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static void *overlay_sw_base = 0;
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struct font_desc const *font = &font_vga_8x16;
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#define CHAR_WIDTH  8
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#define CHAR_HEIGHT 16
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void fb_overlay_init(struct fb_info *fbi, void *base) {
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	text_fb = fbi;
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	overlay_sw_base = base;
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}
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/**
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 * @brief Print character to framebuffer (x, y), where coords are used as
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 *        symbol coordinates, not pixels
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 */
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void fb_overlay_put_char(int x, int y, char ch) {
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	char const *data;
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	uint8_t *dest;
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	int bytes_per_pixel = text_fb->var.bits_per_pixel / 8;
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	data = font->data + (unsigned char)ch * CHAR_HEIGHT * CHAR_WIDTH / 8;
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	dest = overlay_sw_base + bytes_per_pixel * x * CHAR_WIDTH +
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		bytes_per_pixel * y * CHAR_HEIGHT * text_fb->var.xres;
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	for (int i = 0; i < CHAR_HEIGHT; i++) {
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		for (int j = 0; j < CHAR_WIDTH; j++) {
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 			if ((*data) & (1 << (CHAR_WIDTH - j  - 1)))
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				memset(dest, 0xFF, bytes_per_pixel);
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			else
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				memset(dest, 0x00, bytes_per_pixel);
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			dest += bytes_per_pixel;
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		}
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		data++;
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		dest -= CHAR_WIDTH * bytes_per_pixel;
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		dest += text_fb->var.xres * bytes_per_pixel;
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	}
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}
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/**
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 * @brief Print message to fb starting at (x, y), coords are passed as
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 *        symbol numbers, not pixels
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 */
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void fb_overlay_put_string(int x, int y, char *str) {
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	while (*str) {
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		fb_overlay_put_char(x++, y, *str);
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		str++;
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	}
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}
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/**
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 * @brief Same as fb_overlay_put_string(), but stops on '\n'
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 */
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void fb_overlay_put_line(int x, int y, char *str) {
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	while (*str && *str != '\n') {
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		fb_overlay_put_char(x++, y, *str);
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		str++;
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	}
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}
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