Data commit

Task/Bitmap/Lua/bitmap-1.lua

@@ -0,0 +1,22 @@
+function Allocate_Bitmap( width, height )
+    local bitmap = {}
+    for i = 1, width do
+        bitmap[i] = {}
+        for j = 1, height do
+            bitmap[i][j] = {}
+        end
+    end
+    return bitmap
+end
+
+function Fill_Bitmap( bitmap, color )
+    for i = 1, #bitmap do
+        for j = 1, #bitmap[1] do
+            bitmap[i][j] = color
+        end
+    end
+end
+
+function Get_Pixel( bitmap, x, y )
+    return bitmap[x][y]
+end

Task/Bitmap/Lua/bitmap-2.lua

@@ -0,0 +1,4 @@
+bitmap = Allocate_Bitmap( 100, 50 )
+Fill_Bitmap( bitmap, { 15, 200, 80 } )
+pixel = Get_Pixel( bitmap, 20, 25 )
+print( pixel[1], pixel[2], pixel[3] )

Task/Bitmap/Lua/bitmap-3.lua

@@ -0,0 +1,39 @@
+local Bitmap = {
+  new = function(self, width, height)
+    local instance = setmetatable({ width=width, height=height }, self)
+    instance:alloc()
+    return instance
+  end,
+  alloc = function(self)
+   self.pixels = {}
+    for y = 1, self.height do
+      self.pixels[y] = {}
+      for x = 1, self.width do
+        self.pixels[y][x] = 0x00000000
+      end
+    end
+  end,
+  clear = function(self, c)
+    for y = 1, self.height do
+      for x = 1, self.width do
+        self.pixels[y][x] = c or 0x00000000
+      end
+    end
+  end,
+  get = function(self, x, y)
+    x, y = math.floor(x+1), math.floor(y+1) -- given 0-based indices, use 1-based indices
+    if ((x>=1) and (x<=self.width) and (y>=1) and (y<=self.height)) then
+      return self.pixels[y][x]
+    else
+      return nil
+    end
+  end,
+  set = function(self, x, y, c)
+    x, y = math.floor(x+1), math.floor(y+1) -- given 0-based indices, use 1-based indices
+    if ((x>=1) and (x<=self.width) and (y>=1) and (y<=self.height)) then
+      self.pixels[y][x] = c or 0x00000000
+    end
+  end,
+}
+Bitmap.__index = Bitmap
+setmetatable(Bitmap, { __call = function (t, ...) return t:new(...) end })

Task/Bitmap/Lua/bitmap-4.lua

@@ -0,0 +1,28 @@
+local bitmap = Bitmap(32,32)
+
+-- default pixel representation is 32-bit packed ARGB on [0,255]
+bitmap:clear(0xFFFF0000) -- fill with red
+bitmap:set(1, 1, 0xFF00FF00) -- one green pixel
+bitmap:set(2, 2, 0xFF0000FF) -- one blue pixel
+print(string.format("pixel at 0,0 = %x", bitmap:get(0,0)))
+print(string.format("pixel at 1,1 = %x", bitmap:get(1,1)))
+print(string.format("pixel at 2,2 = %x", bitmap:get(2,2)))
+
+-- but note that pixel representation is agnostic..
+-- (it's just a wrapper around a 2d-array of any valid type)
+
+-- want to switch to RGB-tuple on [0,1]??
+bitmap:clear({1,0,0}) -- fill with red
+bitmap:set(1, 1, {0,1,0}) -- one green pixel
+bitmap:set(2, 2, {0,0,1}) -- one blue pixel
+print(string.format("pixel at 0,0 = %s", table.concat(bitmap:get(0,0),", ")))
+print(string.format("pixel at 1,1 = %s", table.concat(bitmap:get(1,1),", ")))
+print(string.format("pixel at 2,2 = %s", table.concat(bitmap:get(2,2),", ")))
+
+-- or strings??
+bitmap:clear("red") -- fill with red
+bitmap:set(1, 1, "green") -- one green pixel
+bitmap:set(2, 2, "blue") -- one blue pixel
+print(string.format("pixel at 0,0 = %s", bitmap:get(0,0)))
+print(string.format("pixel at 1,1 = %s", bitmap:get(1,1)))
+print(string.format("pixel at 2,2 = %s", bitmap:get(2,2)))