* src/bitmap.c:

+ Dither chroma outside of rgb2hsv_default().
    + Clip fromx and fromy values.
  * NOTES:
    + Link to the XTerm control sequences.
  * examples/view.c:
    + Draw status bar.
    + Move with 'h' 'j' 'k' 'l', à la vi.
    + '?' toggles a help menu.

NOTES

@@ -17,11 +17,12 @@ $Id$
         setab=\E[4%p1%dm, setaf=\E[3%p1%dm
 
       From the xterm-16color terminfo:
+      (http://www.sct.gu.edu.au/~anthony/info/X/Xterm_xf86.terminfo)
 
         setab=\E[%?%p1%{8}%<%t%p1%{40}%+%e%p1%{92}%+%;%dm,
         setaf=\E[%?%p1%{8}%<%t%p1%{30}%+%e%p1%{82}%+%;%dm,
 
-      (http://www.sct.gu.edu.au/~anthony/info/X/Xterm_xf86.terminfo)
+      These values can be simply retrieved with a tigetstr() call.
 
    o  I tested the following terminals:
 
@@ -75,9 +76,11 @@ $Id$
        + gnome-terminal (no bright bg)
        + konsole (no bright bg, $blink really blinks)
 
-   o  In an XTerm-compatible terminal, \e[9xm sets bright foreground and
-      \e[10xm bright background colours. Unfortunately all terminals don't
-      support these escape sequences. Here is a testcase:
+   o In an XTerm-compatible terminal, \e[9xm sets bright foreground
+     and \e[10xm bright background colours. Documentation on this can be
+     found at http://ftp.xfree86.org/pub/XFree86/4.2.1/doc/ctlseqs.TXT .
+     Unfortunately all terminals don't support these escape sequences. Here
+     is a testcase:
 
       for fgpre in 3 9; do for fg in 0 4 2 6 1 5 3 7; do
         for bgpre in 4 10; do

examples/view.c

@@ -24,6 +24,7 @@
 #include "config.h"
 
 #include <stdio.h>
+#include <string.h>
 
 #define X_DISPLAY_MISSING 1
 #include <Imlib2.h>
@@ -40,7 +41,7 @@ const enum caca_dithering dithering_list[] =
 
 int main(int argc, char **argv)
 {
-    int quit = 0, update = 1;
+    int quit = 0, update = 1, help = 0;
     int x, y, w, h, zoom = 0;
 
     if(argc != 2)
@@ -108,22 +109,34 @@ int main(int argc, char **argv)
                 zoom = 0;
                 update = 1;
                 break;
+            case CACA_EVENT_KEY_PRESS | 'k':
+            case CACA_EVENT_KEY_PRESS | 'K':
             case CACA_EVENT_KEY_PRESS | CACA_KEY_UP:
                 if(zoom > 0) y -= 1 + h / (2 + zoom) / 8;
                 update = 1;
                 break;
+            case CACA_EVENT_KEY_PRESS | 'j':
+            case CACA_EVENT_KEY_PRESS | 'J':
             case CACA_EVENT_KEY_PRESS | CACA_KEY_DOWN:
                 if(zoom > 0) y += 1 + h / (2 + zoom) / 8;
                 update = 1;
                 break;
+            case CACA_EVENT_KEY_PRESS | 'h':
+            case CACA_EVENT_KEY_PRESS | 'H':
             case CACA_EVENT_KEY_PRESS | CACA_KEY_LEFT:
                 if(zoom > 0) x -= 1 + w / (2 + zoom) / 8;
                 update = 1;
                 break;
+            case CACA_EVENT_KEY_PRESS | 'l':
+            case CACA_EVENT_KEY_PRESS | 'L':
             case CACA_EVENT_KEY_PRESS | CACA_KEY_RIGHT:
                 if(zoom > 0) x += 1 + w / (2 + zoom) / 8;
                 update = 1;
                 break;
+            case CACA_EVENT_KEY_PRESS | '?':
+                help = !help;
+                update = 1;
+                break;
             case CACA_EVENT_KEY_PRESS | 'q':
             case CACA_EVENT_KEY_PRESS | 'Q':
                 quit = 1;
@@ -133,14 +146,17 @@ int main(int argc, char **argv)
 
         if(update)
         {
+            int ww = caca_get_width();
+            int wh = caca_get_height();
+
             caca_clear();
             caca_set_dithering(dithering_list[dithering]);
             if(zoom < 0)
             {
-                int xo = (caca_get_width() - 1) / 2;
-                int yo = (caca_get_height() - 1) / 2;
-                int xn = (caca_get_width() - 1) / (2 - zoom);
-                int yn = (caca_get_height() - 1) / (2 - zoom);
+                int xo = (ww - 1) / 2;
+                int yo = (wh - 1) / 2;
+                int xn = (ww - 1) / (2 - zoom);
+                int yn = (wh - 1) / (2 - zoom);
                 caca_draw_bitmap(xo - xn, yo - yn, xo + xn, yo + yn,
                                  bitmap, pixels);
             }
@@ -154,17 +170,39 @@ int main(int argc, char **argv)
                 if(xn + x > w) x = w - xn;
                 if(yn + y > h) y = h - yn;
                 newbitmap = caca_create_bitmap(32, 2 * xn, 2 * yn, 4 * w,
-                                            0x00ff0000, 0x0000ff00, 0x000000ff);
-                caca_draw_bitmap(0, 0, caca_get_width() - 1,
-                                 caca_get_height() - 1, newbitmap,
+                                           0x00ff0000, 0x0000ff00, 0x000000ff);
+                caca_draw_bitmap(0, 0, ww - 1, wh - 1, newbitmap,
                                  pixels + 4 * (x - xn) + 4 * w * (y - yn));
                 caca_free_bitmap(newbitmap);
             }
             else
             {
-                caca_draw_bitmap(0, 0, caca_get_width() - 1,
-                                 caca_get_height() - 1, bitmap, pixels);
+                caca_draw_bitmap(0, 0, ww - 1, wh - 1, bitmap, pixels);
+            }
+
+            caca_set_color(CACA_COLOR_WHITE, CACA_COLOR_BLUE);
+            caca_draw_line(0, 0, ww - 1, 0, ' ');
+            caca_printf(1, 0, "cacaview %s", VERSION);
+            caca_putstr(ww - strlen("'?' for help") - 1, 0,
+                        "'?' for help");
+
+            if(help)
+            {
+                caca_putstr(2, 2,  " +: zoom in          ");
+                caca_putstr(2, 3,  " -: zoom out         ");
+                caca_putstr(2, 4,  " x: reset zoom       ");
+                caca_putstr(2, 5,  " ------------------- ");
+                caca_putstr(2, 6,  " hjkl: move view     ");
+                caca_putstr(2, 7,  " arrows: move view   ");
+                caca_putstr(2, 8,  " ------------------- ");
+                caca_putstr(2, 9,  " d: dithering method ");
+                caca_putstr(2, 10, " ------------------- ");
+                caca_putstr(2, 11, " ?: help             ");
+                caca_putstr(2, 12, " q: quit             ");
+
+                help = 0;
             }
+
             caca_refresh();
             update = 0;
         }

src/bitmap.c

@@ -221,9 +221,7 @@ static void get_rgb_default(struct caca_bitmap *bitmap, unsigned char *pixels,
             bits = *(uint32_t *)(pixels + 0);
             break;
         case 3:
-            bits = (pixels[0] << 16)
-                    | (pixels[1] << 8)
-                    | (pixels[2]);
+            bits = (pixels[0] << 16) | (pixels[1] << 8) | (pixels[2]);
             break;
         case 2:
             bits = *(uint16_t *)(pixels + 0);
@@ -256,27 +254,25 @@ static void rgb2hsv_default(int r, int g, int b, int *hue, int *sat, int *val)
     if(min > g) min = g; if(max < g) max = g;
     if(min > b) min = b; if(max < b) max = b;
 
-    delta = max - min; /* 0 - 65535 */
-    *val = max; /* 0 - 65535 */
-    *sat = max ? 0x100 * delta / max * 0x100: 0; /* 0 - 65536 */
+    delta = max - min; /* 0 - 0xffff */
+    *val = max; /* 0 - 0xffff */
 
-    if(*sat > (_get_dither() + 24) * 0x400)
+    if(delta)
     {
-        /* XXX: Values should be between 1 and 6, but since we
-         * are dithering, there may be overflows, hence our bigger
-         * *_colors[] tables. */
+        *sat = 0x1000 * delta / max * 0x10; /* 0 - 0xffff */
+
+        /* Generate *hue between 0 and 0x5ffff */
         if( r == max )
             *hue = 0x10000 + 0x100 * (g - b) / delta * 0x100;
         else if( g == max )
             *hue = 0x30000 + 0x100 * (b - r) / delta * 0x100;
         else
             *hue = 0x50000 + 0x100 * (r - g) / delta * 0x100;
-
-        *hue = (*hue + 0x8000 + 0x1000 * _get_dither()) / 0x10000;
     }
     else
     {
         *sat = 0;
+        *hue = 0;
     }
 }
 
@@ -360,6 +356,10 @@ void caca_draw_bitmap(int x1, int y1, int x2, int y2,
             int fromx = w * (x - x1) / (x2 - x1 + 1);
             int fromy = h * (y - y1) / (y2 - y1 + 1);
 
+            /* Clip values (yuck) */
+            if(fromx == 0) fromx = 1;
+            if(fromy == 0) fromy = 1;
+
             /* First get RGB */
             R = 0, G = 0, B = 0;
             get_rgb_default(bitmap, pixels, fromx, fromy, &r, &g, &b);
@@ -377,12 +377,12 @@ void caca_draw_bitmap(int x1, int y1, int x2, int y2,
             /* Now get HSV from RGB */
             rgb2hsv_default(R, G, B, &hue, &sat, &val);
 
-            if(!sat)
+            if(sat < 0x6000 + _get_dither() * 0x800)
                 caca_set_color(white_colors[val * 3 / 0x10000], CACA_COLOR_BLACK);
             else if(val > (_get_dither() + 40) * 0x400)
-                caca_set_color(light_colors[hue], CACA_COLOR_BLACK);
+                caca_set_color(light_colors[(hue + 0x8000 + _get_dither() * 0x1000) / 0x10000], CACA_COLOR_BLACK);
             else
-                caca_set_color(dark_colors[hue], CACA_COLOR_BLACK);
+                caca_set_color(dark_colors[(hue + 0x8000 + _get_dither() * 0x1000) / 0x10000], CACA_COLOR_BLACK);
 
             /* FIXME: choose better characters! */
             ch = (val + 0x200 * _get_dither()) * 10 / 0x10000;