UI: fix img.save(d) to set correct indexes

Author: chrisws

ChangeLog

@@ -1,3 +1,6 @@
+2017-11-28 (0.12.11)
+	Fix img.save(dat) to build correct indexes
+
 2017-11-28 (0.12.10)
 	Released 82f865d61a6eba1c017b8a58e1c892f1b7d6a0c0
 

samples/distro-examples/graphics/img2ascii.bas

@@ -0,0 +1,112 @@
+#http://mattmik.com/articles/ascii/ascii.html
+const chars = "~`!@#$%^&*()+-=[]\;',./_+{}|:"
+const block_width = 4
+const block_height = 6
+
+func calc_block(byref dat, h, y2, w, x2)
+  local y,x,c,r,g,b,n
+  
+  n = 0
+  for y = 0 to h
+    for x = 0 to w
+      c = -dat[y2 + y, x2 + x]
+      r = (c band 0xff0000) rshift 16
+      g = (c band 0xff00) rshift 8
+      b = (c band 0xff)
+      n += (r + g + b) / 3
+    next x
+  next y
+  return n
+end
+
+func get_char(byref tbl, n)
+  local r = tbl[n]
+  if r > 0 then return r
+  for sn in tbl.sorted
+    if (sn > n) then
+      ' round up to the nearest value
+      tbl[n] = tbl[sn]
+      return tbl[sn]
+    endif
+  next n
+  return " "
+end
+
+# analyze the graphic data corresponding to each character in the character set.
+func create_table
+  local img,dat,i,ch,x2,n
+  local w = txtw(chars)
+  local h = txth(chars)
+  local cw = txtw("1")
+  
+  cls: print chars
+  img = image(0, 0, w, h)
+  img.save(dat)
+  cls
+
+  local vals = []
+  local minv = maxint
+  local maxv = 0
+  
+  for i = 1 to len(chars)
+    ch = mid(chars, i, 1)
+    x2 = ((i - 1) * cw)
+    n = calc_block(dat, h - 1, 0, cw - 1, x2) / (w * h)
+    minv = min(minv, n)
+    maxv = max(maxv, n)
+    vals << n
+  next i
+  
+  ' scale the values from 0:255
+  local tbl = {}
+  for i = 1 to len(chars)
+    ch = mid(chars, i, 1)
+    n = 255 * (vals[i - 1] - minv) / (maxv - minv)
+    vals[i - 1] = n
+    tbl[n] = ch
+  next i
+  
+  sort vals
+  tbl["sorted"] = vals
+  return tbl
+end
+
+sub imageToAscii(path)
+  local img,dat,pic,bly,blx,y2,x2,n,minv,maxv,row
+  local tbl = create_table()
+
+  img = image(path)
+  img.save(dat)
+
+  local w = img.width
+  local h = img.height
+  local blw = w / block_width
+  local blh = h / block_height
+  local vals = []
+  local minv = maxint
+  local maxv = 0
+  
+  dim pic(blh, blw)
+
+  for bly = 0 to blh - 1
+    for blx = 0 to blw - 1
+      y2 = bly * block_height
+      x2 = blx * block_width
+      n = calc_block(dat, block_height, y2, block_width - 1, x2) / (w * h)
+      minv = min(minv, n)
+      maxv = max(maxv, n)
+      pic[bly,blx] = n 
+    next blx
+  next bly
+
+  for bly = 0 to blh - 1
+    row = ""
+    for blx = 0 to blw - 1
+      n = 255 * (pic[bly,blx] - minv) / (maxv - minv)
+      row += get_char(tbl, n)
+    next blx
+    print row
+  next bly
+end
+
+imageToAscii("tree.png")

src/ui/image.cpp

@@ -391,7 +391,7 @@ void cmd_image_save(var_s *self) {
         saved = true;
       }
     } else if (array != NULL) {
-      v_tomatrix(array, w, h);
+      v_tomatrix(array, h, w);
       for (int y = 0; y < h; y++) {
         int yoffs = (4 * y * w);
         for (int x = 0; x < w; x++) {