Add UTF-8 braille output

Makefile

@@ -14,6 +14,7 @@ all: ${PROJECT}
 
 OBJS=	args.o \
 	ascii.o \
+	braille.o \
 	counter.o \
 	draw.o \
 	fnv.o \

args.c

@@ -20,6 +20,7 @@ static void usage(const char *msg) {
         "            [-m MODE] [-r] [-s] [-S] [-x] [FILE]\n"
         "\n"
         "Common options:\n"
+        "    -b: render to UTF-8 braille characters\n"
         "    -d WxH: set width and height (e.g. \"-d 72x40\", \"-d 640x480\")\n"
         "    -f: flip x & y axes in plot\n"
         "    -h: print this message\n"
@@ -52,11 +53,14 @@ static void parse_dims(config *cfg, const char *opt) {
 
 void args_handle(config *cfg, int argc, char **argv) {
     int fl;
-    while ((fl = getopt(argc, argv, "Acd:fhl:m:rsSx")) != -1) {
+    while ((fl = getopt(argc, argv, "Abcd:fhl:m:rsSx")) != -1) {
         switch (fl) {
         case 'A':               /* no axis */
             cfg->axis = false;
             break;
+        case 'b':               /* braille */
+            cfg->plot_type = PLOT_BRAILLE;
+            break;
         case 'c':               /* use colorblind-safe default colors */
             cfg->colorblind = true;
             break;

braille.c

@@ -0,0 +1,176 @@
+#include "braille.h"
+#include "scale.h"
+
+/* Plotting to UTF-8 braille characters. */
+
+static void init_rows(plot_info *pi);
+static void draw_axes(plot_info *pi);
+static void print_header(plot_info *pi, uint8_t columns);
+static void plot_points(config *cfg, plot_info *pi, data_set *ds);
+
+static void free_rows(plot_info *pi);
+
+static void utf8(int cp, char c[]) {
+    if (cp <= 0x7f) {
+        c[0] =  cp;
+        return;
+    }
+
+    if (cp <= 0x7ff) {
+        c[0] = (cp >>  6) + 192;
+        c[1] = (cp  & 63) + 128;
+        return;
+    }
+
+    if (0xd800 <= cp && cp <= 0xdfff) {
+        /* invalid */
+        goto error;
+    }
+
+    if (cp <= 0xffff) {
+        c[0] =  (cp >> 12) + 224;
+        c[1] = ((cp >>  6) &  63) + 128;
+        c[2] =  (cp  & 63) + 128;
+        return;
+    }
+
+    if (cp <= 0x10ffff) {
+        c[0] =  (cp >> 18) + 240;
+        c[1] = ((cp >> 12) &  63) + 128;
+        c[2] = ((cp >>  6) &  63) + 128;
+        c[3] =  (cp  & 63) + 128;
+        return;
+    }
+
+error:
+
+    fprintf(stderr, "codepoint out of range\n");
+    exit(1);
+}
+
+int braille_plot(config *cfg, plot_info *pi, data_set *ds) {
+    struct {
+        int j;
+        int i;
+        int m;
+    } braille[] = {
+        { 0, 0, 0x2801 }, { 1, 0, 0x2808 },
+        { 0, 1, 0x2802 }, { 1, 1, 0x2810 },
+        { 0, 2, 0x2804 }, { 1, 2, 0x2820 },
+        { 0, 3, 0x2840 }, { 1, 3, 0x2880 }
+    };
+
+    init_rows(pi);
+    if (cfg->axis) {
+        draw_calc_axis_pos(pi);
+        draw_axes(pi);
+    }
+
+    print_header(pi, ds->columns);
+    plot_points(cfg, pi, ds);
+
+    for (size_t i = 0; i < pi->h - 3; i += 4) {
+        for (size_t j = 0; j < pi->w - 1; j += 2) {
+            char s[5] = { 0x00, 0x00, 0x00, 0x00, 0x00 };
+            size_t k;
+            int cp;
+
+            cp = 0x2800; /* blank */
+
+            for (k = 0; k < sizeof braille / sizeof *braille; k++) {
+                if (pi->rows[i + braille[k].i][j + braille[k].j] != ' ') {
+                    cp |= braille[k].m;
+                }
+            }
+
+            utf8(cp, s);
+
+            printf("%s", s);
+        }
+        printf("\n");
+    }
+    free_rows(pi);
+    return 0;
+}
+
+static void free_rows(plot_info *pi) {
+    if (pi) {
+        for (size_t i = 0; i < pi->h; i++) {
+            free(pi->rows[i]);
+        }
+        free(pi->rows);
+        pi->rows = NULL;
+    }
+}
+
+static void init_rows(plot_info *pi) {
+    char **rows = calloc(pi->h, sizeof(*rows));
+    if (rows == NULL) { err(1, "calloc"); }
+
+    for (size_t i = 0; i < pi->h; i++) {
+        rows[i] = malloc(pi->w + 1);
+        if (rows[i] == NULL) { err(1, "malloc"); }
+        memset(rows[i], ' ', pi->w);
+        rows[i][pi->w] = '\0';
+    }
+    pi->rows = rows;
+}
+
+static void print_header(plot_info *pi, uint8_t columns) {
+    if (pi->log_x) {
+        printf("    x: log [%g - %g]", exp(pi->min_x), exp(pi->max_x));
+    } else {
+        printf("    x: [%g - %g]", pi->min_x, pi->max_x);
+    }
+
+    if (pi->log_y) {
+        printf("    y: log [%g - %g]", exp(pi->min_y), exp(pi->max_y));
+    } else {
+        printf("    y: [%g - %g]", pi->min_y, pi->max_y);
+    }
+
+    printf("\n");
+}
+
+static void draw_axes(plot_info *pi) {
+    char c;
+
+    /* TODO: use same step size calc as SVG */
+
+    for (size_t i = 0; i < pi->h; i++) {
+        if (pi->draw_y_axis) {
+            c = '|';
+        } else {
+            c = ' ';
+        }
+
+        pi->rows[i][pi->axis_x] = c;
+    }
+
+    for (size_t i = 0; i < pi->w; i++) {
+        if (pi->draw_x_axis) {
+            c = '-';
+        } else {
+            c = ' ';
+        }
+        pi->rows[pi->axis_y][i] = c;
+    }
+
+    pi->rows[pi->axis_y][pi->axis_x] = '+';
+}
+
+static void plot_points(config *cfg, plot_info *pi, data_set *ds) {
+    for (uint8_t c = 0; c < ds->columns; c++) {
+        for (size_t r = 0; r < ds->rows; r++) {
+            point *p = &ds->pairs[c][r];
+
+            if (IS_EMPTY(p->x) || IS_EMPTY(p->y)) { continue; }
+            transform_t t = scale_get_transform(pi->log_x, pi->log_y);
+            scaled_point sp;
+            scale_point(pi, p, &sp, t);
+            LOG(2, "{ %g, %g } => [%u, %u]\n", p->x, p->y, sp.x, sp.y);
+
+            pi->rows[sp.y][sp.x] = '@';
+        }
+    }
+}

braille.h

@@ -0,0 +1,9 @@
+#ifndef BRAILLE_H
+#define BRAILLE_H
+
+#include "guff.h"
+#include "draw.h"
+
+int braille_plot(config *cfg, plot_info *pi, data_set *ds);
+
+#endif

draw.c

@@ -5,6 +5,7 @@
 #include "scale.h"
 
 #include "ascii.h"
+#include "braille.h"
 #include "svg.h"
 #include "counter.h"
 
@@ -50,6 +51,10 @@ int draw(config *cfg, data_set *ds) {
         res = ascii_plot(cfg, &pi, ds);
         break;
 
+    case PLOT_BRAILLE:
+        res = braille_plot(cfg, &pi, ds);
+        break;
+
     case PLOT_SVG:
         res = svg_plot(cfg, &pi, ds);
         break;

man/guff.1.ronn

@@ -4,7 +4,7 @@ guff(1) -- a plot device
 ## SYNOPSIS
 
 `guff` [-A] [-c] [-d WxH] [-f] [-h] [-l xyc]
-       [-m MODE] [-r] [-s] [-S] [-x] [FILE]
+       [-m MODE] [-r] [-s|-b] [-S] [-x] [FILE]
 
 
 ## DESCRIPTION
@@ -66,9 +66,10 @@ end-of-stream or a blank line is reached:
 
     $ guff
 
-Same, but generate SVG:
+Same, but generate SVG and UTF-8 braille characters:
 
     $ guff -s
+    $ guff -b
 
 Read number rows from a file:
 

types.h

@@ -15,6 +15,7 @@ typedef struct {
 
 typedef enum {
     PLOT_ASCII,
+    PLOT_BRAILLE,
     PLOT_SVG,
 } output_t;