Implement buffered windows to support transparancy

gfx/render/buffer.lua

@@ -0,0 +1,232 @@
+local Util = require("util")
+
+local DEFAULT_C = " "
+local DEFAULT_FG = colors.white
+local DEFAULT_BG = colors.black
+
+local function ensureC(cVal)
+  return (cVal ~= nil and #cVal == 1 and cVal) or DEFAULT_C
+end
+
+local WindowBuffer = {}
+
+-- Create a shallow wrapper for window object
+function WindowBuffer.wrapWindow(w, defaultC, defaultFg, defaultBg, clearColor)
+  defaultC = ensureC(defaultC)
+  defaultFg = defaultFg or DEFAULT_FG
+  defaultBg = defaultBg or DEFAULT_BG
+  clearColor = clearColor or DEFAULT_BG
+
+  local obj = {}
+
+  function obj.blit(text, fg, bg)
+    w.blit(text, fg, bg)
+  end
+
+  function obj.flush() end
+  function obj.getSize()
+    return w.getSize()
+  end
+
+  function obj._setPixel(x, y, c, fg, bg)
+    w.setCursorPos(x, y)
+    w.setFgColor(fg or defaultFg)
+    w.setBgColor(bg or defaultBg)
+    w.write(c or defaultC)
+  end
+
+  function obj.setPixel(x, y, c, fg, bg)
+    local width, height = obj.getSize()
+    Util.boundCheck(x, y, width, height)
+    obj._setPixel(x, y, c, fg, bg)
+  end
+
+  -- Partial writes are not possible for native window access
+  obj._writePixel = obj._setPixel
+  obj.writePixel = obj.setPixel
+
+  function obj.setCursorPos(x, y)
+    w.setCursorPos(x, y)
+  end
+
+  function obj.getCursorPos()
+    return w.getCursorPos()
+  end
+
+  function obj.clear()
+    w.setBgColor(clearColor)
+    --w.setFgColor(clearColor) -- Shouldn't matter for native clear
+    w.clear()
+  end
+
+  return obj
+end
+
+function WindowBuffer.new(width, height, clearC, clearFg, clearBg)
+  clearC = ensureC(clearC)
+  clearFg = clearFg or DEFAULT_FG
+  clearBg = clearBg or DEFAULT_BG
+
+  local obj = {}
+
+  local function setState(o, c, fg, bg)
+    o.c = c
+    o.bg = bg
+    o.fg = fg
+    return o
+  end
+
+  local function writeState(o, c, fg, bg)
+    o.c = c or o.c
+    o.bg = bg or o.bg
+    o.fg = fg or o.fg
+    return o
+  end
+
+  local buffer = {}
+  for i=1,height do
+    local line = {}
+    for j=1,width do
+      line[j] = setState({})
+    end
+    buffer[i] = line
+  end
+
+  local pX, pY = 1, 1
+
+  function obj.blit(text, fg, bg)
+    assert(#text == #fg, "Foreground color blit length must match text length")
+    assert(#text == #bg, "Background color blit length must match text length")
+
+    local line = buffer[pY]
+    local baseX = pX
+    for i=1,math.min(#text, width - baseX - 1) do
+      local blitChar = line[i]
+      blitChar.c = text:sub(i, i)
+      blitChar.fg = fg:sub(i, i)
+      blitChar.bg = bg:sub(i, i)
+    end
+
+    pX = pX + #text
+  end
+
+  function obj._setPixel(x, y, c, fg, bg)
+    setState(buffer[y][x], c, fg, bg)
+  end
+
+  function obj.setPixel(x, y, c, fg, bg)
+    Util.boundCheck(x, y, width, height)
+    obj._setPixel(x, y, c, fg, bg)
+  end
+
+  function obj._writePixel(x, y, c, fg, bg)
+    writeState(buffer[y][x], c, fg, bg)
+  end
+
+  function obj.writePixel(x, y, c, fg, bg)
+    Util.boundCheck(x, y, width, height)
+    obj._writePixel(x, y, c, fg, bg)
+  end
+
+  function obj.setCursorPos(x, y)
+    pX, pY = x, y
+  end
+
+  function obj.getCursorPos()
+    return pX, pY
+  end
+
+  function obj.clear()
+    for i=1,height do
+      local line = buffer[i]
+      for j=1,width do
+        setState(line[j], clearC, clearFg, clearBg)
+      end
+    end
+  end
+
+  -- TODO: Implement partial flush; obj.flush(win, offsetX, offsetY, width, height)
+
+  function obj.flush(win, offsetX, offsetY)
+    for i=1,height do
+      local line = buffer[i]
+      for j=1,width do
+        local entry = line[j]
+        win._writePixel(j + offsetX, i + offsetY, entry.c, entry.fg, entry.bg)
+      end
+    end
+  end
+
+  return obj
+end
+
+function WindowBuffer.shallowChild(windowBuffer, width, height, offsetX, offsetY, clearC, clearFg, clearBg)
+  -- Assume static for now
+  local parentWidth, parentHeight = windowBuffer.getSize()
+  Util.boundCheck(offsetX, offsetY, parentWidth, parentHeight)
+  Util.boundCheck(offsetX + width, offsetY + height, parentWidth, parentHeight)
+
+  clearC = ensureC(clearC)
+  clearFg = clearFg or DEFAULT_FG
+  clearBg = clearBg or DEFAULT_BG
+
+  local obj = {}
+
+  local pX, pY = 1, 1
+
+  local function setCursorPos()
+    windowBuffer.setCursorPos(pX + offsetX, pY + offsetY)
+  end
+
+  function obj.blit(text, fg, bg)
+    setCursorPos()
+    windowBuffer.blit(text, fg, bg)
+    pX = pX + #text
+  end
+
+  function obj._setPixel(c, fg, bg)
+    setCursorPos()
+    windowBuffer._setPixel(c, fg, bg)
+  end
+
+  function obj.setPixel(c, fg, bg)
+    setCursorPos()
+    windowBuffer.setPixel(c, fg, bg)
+  end
+
+  function obj._writePixel(c, fg, bg)
+    setCursorPos()
+    windowBuffer._writePixel(c, fg, bg)
+  end
+
+  function obj.writePixel(c, fg, bg)
+    setCursorPos()
+    windowBuffer.writePixel(c, fg, bg)
+  end
+
+  function obj.setCursorPos(x, y)
+    pX, pY = x, y
+  end
+
+  function obj.getCursorPos()
+    return pX, pY
+  end
+
+  function obj.getSize()
+    return width, height
+  end
+
+  function obj.clear()
+    for i=1,height do
+      for j=1,width do
+        windowBuffer._setPixel(clearC, clearFg, clearBg)
+      end
+    end
+  end
+
+  obj.flush = windowBuffer.flush()
+
+  return obj
+end
+
+return WindowBuffer