Working but not full implementation of Sprites

conf.lua

@@ -1,3 +1,10 @@
+-- conf.lua
+if love._os == "Windows" then
+  local ffi = require "ffi"
+  ffi.cdef[[ bool SetProcessDPIAware(); ]]
+  ffi.C.SetProcessDPIAware();
+end
+
 function love.conf(t)
     -- TODO: only enable in debug mode
     t.console = true

header.lua

@@ -1,7 +1,7 @@
 !if LOVE2D then
 require("playbit.graphics")
 
---[[ since there is no CoreLibs/playdate, this file should always 
+--[[ since there is no CoreLibs/playdate, this file should always
 be included here so the methods are always available ]]--
 require("playdate.playdate")
 --[[ not really a way around including this one, but probably doesn't really
@@ -19,7 +19,14 @@ function import(path)
 end
 
 local firstFrame = true
-local windowWidth, windowHeight = playbit.graphics.getWindowSize()
+
+-- initialize playbit window using initial love.window mode
+local windowWidth, windowHeight, windowFlags = love.window.getMode()
+playbit.graphics.setWindowSize(windowWidth, windowHeight)
+playbit.graphics.setFullscreen(windowFlags.fullscreen)
+-- scale canvas to fit the window
+local canvasWidth, canvasHeight = playbit.graphics.getCanvasSize()
+playbit.graphics.setCanvasScale(windowWidth / canvasWidth)
 
 playbit.graphics.canvas:setFilter("nearest", "nearest")
 
@@ -35,6 +42,8 @@ math.randomseed(os.time())
 local font = playdate.graphics.font.new("fonts/Phozon/Phozon")
 playdate.graphics.setFont(font)
 
+local updateCoroutine
+
 function love.draw()
   -- must be changed at start of frame when canvas is not active
   local newCanvasWidth, newCanvasHeight = playbit.graphics.getCanvasSize()
@@ -66,9 +75,8 @@ function love.draw()
 
   -- render to canvas to allow 2x scaling
   love.graphics.setCanvas(playbit.graphics.canvas)
-  love.graphics.setShader(playbit.graphics.shader)
 
-  --[[ 
+  --[[
     Love2d won't allow a canvas to be set outside of the draw function, so we need to do this on the first frame of draw.
     Otherwise setting the bg color outside of playdate.update() won't be consistent with PD.
   --]]
@@ -86,7 +94,14 @@ function love.draw()
   love.graphics.translate(playbit.graphics.drawOffset.x, playbit.graphics.drawOffset.y)
 
   -- main update
-  playdate.update()
+  if not updateCoroutine or coroutine.status(updateCoroutine) == "dead" then
+    updateCoroutine = coroutine.create(playdate.update)
+  end
+
+  local ok, err = coroutine.resume(updateCoroutine)
+  if not ok then
+    error(err)
+  end
 
   -- debug draw
   if playdate.debugDraw then
@@ -102,22 +117,19 @@ function love.draw()
   love.graphics.setCanvas()
 
   -- clear shader so that canvas is rendered normally
-  love.graphics.setShader()
-
-  -- always render pure white so its not tinted
-  local r, g, b = love.graphics.getColor()
-  love.graphics.setColor(1, 1, 1, 1)
+  local shader = love.graphics.getShader()
+  love.graphics.setShader(playbit.graphics.shaders.final)
 
   -- draw canvas to screen
   local currentCanvasScale = playbit.graphics.getCanvasScale()
   local x, y = playbit.graphics.getCanvasPosition()
   love.graphics.draw(playbit.graphics.canvas, x, y, 0, currentCanvasScale, currentCanvasScale)
 
-  -- reset back to set color
-  love.graphics.setColor(r, g, b, 1)
+  -- reset back the shader
+  love.graphics.setShader(shader)
 
   -- update emulated input
   playdate.updateInput()
 end
 
-!end
+!end

playbit/graphics.lua

@@ -10,20 +10,47 @@ module.COLOR_BLACK = { 49 / 255, 47 / 255, 40 / 255, 1 }
 
 module.colorWhite = module.COLOR_WHITE
 module.colorBlack = module.COLOR_BLACK
-module.shader = love.graphics.newShader("playdate/shader")
+
+module.shaders =
+{
+  final   = love.graphics.newShader("playbit/shaders/final.glsl"),
+  color   = love.graphics.newShader("playbit/shaders/color.glsl"),
+  pattern = love.graphics.newShader("playbit/shaders/pattern.glsl"),
+  image   = { }
+}
+
+local shader = love.filesystem.read("playbit/shaders/image.glsl")
+for i = 0, 9 do
+  local src = "#define DRAW_MODE " .. i .. "\n" .. shader
+  module.shaders.image[i] = love.graphics.newShader(src)
+end
+
+module.shader = nil
 module.drawOffset = { x = 0, y = 0}
 module.drawColorIndex = 1
 module.drawColor = module.colorWhite
 module.backgroundColorIndex = 0
 module.backgroundColor = module.colorBlack
 module.activeFont = {}
-module.drawMode = "copy"
+module.imageDrawMode = 0
 module.canvas = love.graphics.newCanvas()
 module.contextStack = {}
 -- shared quad to reduce gc
 module.quad = love.graphics.newQuad(0, 0, 1, 1, 1, 1)
 module.lastClearColor = module.colorWhite
-module.drawPattern = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
+module.drawPattern = nil
+module.lineWidth = 1
+
+module.textToImageDrawMode = {
+  ["copy"] = 0,
+  ["inverted"] = 7,
+  ["xor"] = 5,
+  ["nxor"] = 6,
+  ["whitetransparent"] = 1,
+  ["blacktransparent"] = 2,
+  ["fillwhite"] = 3,
+  ["fillblack"] = 4
+}
 
 local canvasScale = 1
 local canvasWidth = 400
@@ -107,44 +134,62 @@ end
 ---@param white table An array of 4 values that correspond to RGBA that range from 0 to 1.
 ---@param black table An array of 4 values that correspond to RGBA that range from 0 to 1.
 function module.setColors(white, black)
-  if white == nil then
-    white = module.COLOR_WHITE
-  end
-  if black == nil then
-    black = module.COLOR_BLACK
-  end
-
-  module.colorWhite = white
-  module.colorBlack = black
-  module.shader:send("white", white)
-  module.shader:send("black", black)
-
-  if module.backgroundColorIndex == 1 then
-    module.backgroundColor = module.colorWhite
-  else
-    module.backgroundColor = module.colorBlack
-  end
+  module.colorWhite = white or module.COLOR_WHITE
+  module.colorBlack = black or module.COLOR_BLACK
+  module.shaders.final:send("white", white)
+  module.shaders.final:send("black", black)
+end
+
+local function copyAndSwapCanvases()
+  local shader = love.graphics.getShader()
 
-  if module.drawColorIndex == 1 then
-    module.drawColor = module.colorWhite
-  else
-    module.drawColor = module.colorBlack
+  -- create second canvas if needed of the same size.
+  if not module.canvas2 then
+    local w, h = module.canvas:getWidth(), module.canvas:getHeight()
+    module.canvas2 = love.graphics.newCanvas(w, h)
   end
+
+  -- copy original canvas to another one
+  love.graphics.push()
+  love.graphics.origin()
+  love.graphics.setCanvas(module.canvas2)
+  love.graphics.setShader()
+  love.graphics.draw(module.canvas)
+  love.graphics.pop()
+
+  -- swap canvases.
+  module.canvas, module.canvas2 = module.canvas2, module.canvas
+
+  -- restore shader and the color
+  love.graphics.setShader(shader)
 end
 
-function module.updateContext()
-  if #module.contextStack == 0 then
-    return
-  end
+local function getShader(mode, imageDrawMode)
+  if mode == "line" then
+    return module.shaders.color
 
-  local activeContext = module.contextStack[#module.contextStack]
+  elseif mode == "fill" then
+    if module.drawPattern then
+      return module.shaders.pattern
+    else
+      return module.shaders.color
+    end
 
-  -- love2d doesn't allow calling newImageData() when canvas is active
-  love.graphics.setCanvas()
-  local imageData = activeContext._canvas:newImageData()
-  love.graphics.setCanvas(activeContext._canvas)
+  elseif mode == "image" then
+    return module.shaders.image[imageDrawMode]
+  end
+end
 
-  -- update image
-  activeContext.data:replacePixels(imageData)
+function module.setDrawMode(mode, imageDrawMode)
+  local shader = getShader(mode, imageDrawMode or module.imageDrawMode)
+  if module.shader ~= shader then
+    module.shader = shader
+    -- TODO: we have to do this before every drawing call.
+    if shader:hasUniform("canvas") then
+      copyAndSwapCanvases()
+      shader:send("canvas", module.canvas2)
+    end
+    love.graphics.setShader(shader)
+  end
 end
-!end
+!end

playbit/shaders/color.glsl

@@ -0,0 +1,11 @@
+#pragma language glsl3
+
+extern vec4 drawColor;
+
+vec4 effect(vec4 color, Image tex, vec2 tex_coords, vec2 screen_coords)
+{
+    float outColor = drawColor.r;
+    float outAlpha = drawColor.a;
+
+    return vec4(outColor, outColor, outColor, outAlpha);
+}

playbit/shaders/final.glsl

@@ -0,0 +1,15 @@
+#pragma language glsl3
+
+extern vec4 white = vec4(176.0f / 255.0f, 174.0f / 255.0f, 167.0f / 255.0f, 1);
+extern vec4 black = vec4( 49.0f / 255.0f,  47.0f / 255.0f,  40.0f / 255.0f, 1);
+
+vec4 effect(vec4 color, Image tex, vec2 tex_coords, vec2 screen_coords)
+{
+    vec4 inColor = Texel(tex, tex_coords) * color;
+
+    vec4 outColor;
+    outColor.rgb = mix(black.rgb, white.rgb, inColor.r);
+    outColor.a   = 1;
+
+    return outColor;
+}

playbit/shaders/image.glsl

@@ -0,0 +1,49 @@
+#pragma language glsl3
+
+extern Image canvas;
+
+vec4 effect(vec4 color, Image tex, vec2 tex_coords, vec2 screen_coords)
+{
+    vec4  texColor   = Texel(tex, tex_coords);
+    float grayscale  = dot(texColor.rgb, vec3(0.2126, 0.7152, 0.0722));
+    float inColor    = step(0.5, grayscale);
+    float inAlpha    = step(0.5, texColor.a);
+
+#if DRAW_MODE == 1   // White Transparent
+    float outColor   = inColor;
+    float outAlpha   = inAlpha * (1.0 - inColor);
+
+#elif DRAW_MODE == 2 // Black Transparent
+    float outColor   = inColor;
+    float outAlpha   = inAlpha * inColor;
+
+#elif DRAW_MODE == 3 // Fill White
+    float outColor   = 1;
+    float outAlpha   = inAlpha;
+
+#elif DRAW_MODE == 4 // Fill Black
+    float outColor   = 0;
+    float outAlpha   = inAlpha;
+
+#elif DRAW_MODE == 5 // XOR
+    vec4 canvasColor = Texel(canvas, screen_coords / love_ScreenSize.xy);
+    float outColor   = abs(canvasColor.r - inColor);
+    float outAlpha   = inAlpha;
+
+#elif DRAW_MODE == 6 // NXOR
+    vec4 canvasColor = Texel(canvas, screen_coords / love_ScreenSize.xy);
+    float outColor   = 1.0 - abs(canvasColor.r - inColor);
+    float outAlpha   = inAlpha;
+
+#elif DRAW_MODE == 7 // Inverted
+    float outColor   = 1.0 - inColor;
+    float outAlpha   = inAlpha;
+
+#else                // Copy
+    float outColor   = inColor;
+    float outAlpha   = inAlpha;
+
+#endif
+
+    return vec4(outColor, outColor, outColor,  outAlpha);
+}

playbit/shaders/pattern.glsl

@@ -0,0 +1,15 @@
+#pragma language glsl3
+
+extern float pattern[64];
+
+vec4 effect(vec4 color, Image tex, vec2 tex_coords, vec2 screen_coords)
+{
+    // Use mod() to get the position of the current pixel within the 8x8 pattern
+    int x = int(mod(screen_coords.x, 8.0));
+    int y = int(mod(screen_coords.y, 8.0));
+
+    float outColor = pattern[x + y * 8];
+    float outAlpha = 1;
+
+    return vec4(outColor, outColor, outColor, outAlpha);
+}

playbit/util.lua

@@ -23,4 +23,24 @@ function module.sign(a)
   else
     return 0
   end
+end
+
+function module.clamp01(x)
+  if x <= 0 then
+    return 0
+  elseif x >= 1 then
+    return 1
+  else
+    return x
+  end
+end
+
+function module.clamp(x, min, max)
+  if x <= min then
+    return min
+  elseif x >= max then
+    return max
+  else
+    return x
+  end
 end