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	tffplot.c - ploot - simple plotting tools
	git clone git://bitreich.org/ploot git://enlrupgkhuxnvlhsf6lc3fziv5h2hhfrinws65…
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	---
	tffplot.c (3180B)
	---
	1 #include "ffplot.h"
	2
	3 #include <arpa/inet.h>
	4 #include <stddef.h>
	5 #include <string.h>
	6 #include <stdio.h>
	7 #include <stdint.h>
	8
	9 #include "font.h"
	10 #include "util.h"
	11
	12 /*
	13 * Convert (x,y) coordinates to (row,col) for printing into the buffer.
	14 * The buffer only contain one number, so the coordinate is a single int…
	15 * width * y + y.
	16 * The coordinates are shifted by offx and offy to permit relative coord…
	17 *
	18 * The convention used: y
	19 * - (0,0) is at the lower left corner of the plotvas. \|
	20 * - (0,1) is above it. +--x
	21 */
	22 void
	23 ffplot_pixel(struct ffplot plot, struct ffcolor color,
	24 int x, int y)
	25 {
	26 x += plot->x;
	27 y += plot->y;
	28 if (x < 0 \|\| x >= plot->w \|\| y < 0 \|\| y >= plot->h)
	29 return;
	30 memcpy(plot->buf + plot->w * (plot->h - 1 - y) + x, color, sizeo…
	31 }
	32
	33 void
	34 ffplot_rectangle(struct ffplot plot, struct ffcolor color,
	35 int y1, int x1,
	36 int y2, int x2)
	37 {
	38 int x, y, ymin, xmin, ymax, xmax;
	39
	40 ymin = MIN(y1, y2); ymax = MAX(y1, y2);
	41 xmin = MIN(x1, x2); xmax = MAX(x1, x2);
	42
	43 for (y = ymin; y <= ymax; y++)
	44 for (x = xmin; x <= xmax; x++)
	45 ffplot_pixel(plot, color, x, y);
	46 }
	47
	48 /*
	49 * From Bresenham's line algorithm and dcat's tplot.
	50 */
	51 void
	52 ffplot_line(struct ffplot plot, struct ffcolor color,
	53 int x0, int y0,
	54 int x1, int y1)
	55 {
	56 int dy, dx, sy, sx, err, e;
	57
	58 sx = x0 < x1 ? 1 : -1;
	59 sy = y0 < y1 ? 1 : -1;
	60 dx = ABS(x1 - x0);
	61 dy = ABS(y1 - y0);
	62 err = (dy > dx ? dy : -dx) / 2;
	63
	64 for (;;) {
	65 ffplot_pixel(plot, color, x0, y0);
	66
	67 if (y0 == y1 && x0 == x1)
	68 break;
	69
	70 e = err;
	71 if (e > -dy) {
	72 y0 += sy;
	73 err -= dx;
	74 }
	75 if (e < dx) {
	76 x0 += sx;
	77 err += dy;
	78 }
	79 }
	80 }
	81
	82 /*
	83 * Draw a coloured glyph from font f centered on y.
	84 */
	85 int
	86 ffplot_char(struct ffplot plot, struct ffcolor color, struct font *ft,…
	87 int x, int y)
	88 {
	89 int yf, xf, wf;
	90
	91 if (c & 0x80)
	92 c = '\0';
	93 y -= ft->height / 2;
	94 wf = font_width(ft, c);
	95 for (xf = 0; xf < wf; xf++)
	96 for (yf = 0; yf < ft->height; yf++)
	97 if (ft->glyph[(int)c][wf * (ft->height - yf) + x…
	98 ffplot_pixel(plot, color, x + xf, y + yf…
	99 return wf + 1;
	100 }
	101
	102 /*
	103 * Draw a left aligned string without wrapping it.
	104 */
	105 size_t
	106 ffplot_text_left(struct ffplot plot, struct ffcolor color, struct font…
	107 char *s, int x, int y)
	108 {
	109 for (; *s != '\0'; s++)
	110 x += ffplot_char(plot, color, ft, *s, x, y);
	111 return x;
	112 }
	113
	114 /*
	115 * Draw a center aligned string without wrapping it.
	116 */
	117 size_t
	118 ffplot_text_center(struct ffplot plot, struct ffcolor color, struct fo…
	119 char *s, int x, int y)
	120 {
	121 x -= font_strlen(ft, s) / 2;
	122 return ffplot_text_left(plot, color, ft, s, x, y);
	123 }
	124
	125 /*
	126 * Draw a right aligned string without wrapping it.
	127 */
	128 size_t
	129 ffplot_text_right(struct ffplot plot, struct ffcolor color, struct fon…
	130 char *s, int x, int y)
	131 {
	132 x -= font_strlen(ft, s);
	133 return ffplot_text_left(plot, color, ft, s, x, y);
	134 }
	135
	136 void
	137 ffplot_print(FILE fp, struct ffplot plot)
	138 {
	139 uint32_t w, h;
	140
	141 w = htonl(plot->w);
	142 h = htonl(plot->h);
	143
	144 fprintf(stdout, "ffplot");
	145 fwrite(&w, sizeof(w), 1, fp);
	146 fwrite(&h, sizeof(h), 1, fp);
	147 fwrite(plot->buf, plot->w * plot->h, sizeof(*plot->buf), fp);
	148 }