Added functionality to draw pixel and read color

README.md

@@ -159,6 +159,42 @@ Draw a line between two points:
 
 `alpha` - alpha channel 0..255. Optional parameter for rgba textures
 
+#### drawpixels.pixel(buffer_info, x, y, red, green, blue, alpha)
+Draw a pixel:
+
+`buffer_info` - buffer information
+
+`x` - x position of pixel
+
+`y` - y position of pixel
+
+`red` - red channel of the color 0..255
+
+`green` - green channel of the color 0..255
+
+`blue` - blue channel of the color 0..255
+
+`alpha` - alpha channel 0..255. Optional parameter for rgba textures
+
+#### drawpixels.color(buffer_info, x, y)
+Read color from a position in the buffer:
+
+`buffer_info` - buffer information
+
+`x` - x position to get color from
+
+`y` - y position to get color from
+
+RETURNS:
+
+`red` - red channel of the color 0..255
+
+`green` - green channel of the color 0..255
+
+`blue` - blue channel of the color 0..255
+
+`alpha` - alpha channel 0..255. Optional parameter for rgba textures
+
 --------
 
 If you have any questions or suggestions contact me: [email protected]

drawpixels/src/drawpixels.cpp

@@ -182,6 +182,50 @@ static int draw_line(lua_State* L) {
   return 0;
 }
 
+static int draw_pixel(lua_State* L) {
+  int top = lua_gettop(L) + 4;
+
+  read_and_validate_buffer_info(L, 1);
+  int32_t x = luaL_checknumber(L, 2);
+  int32_t y = luaL_checknumber(L, 3);
+  uint32_t r = luaL_checknumber(L, 4);
+  uint32_t g = luaL_checknumber(L, 5);
+  uint32_t b = luaL_checknumber(L, 6);
+  uint32_t a = 0;
+  if (lua_isnumber(L, 7) == 1)
+  {
+    a = luaL_checknumber(L, 7);
+  }
+
+  putpixel(x, y, r, g, b, a);
+
+  assert(top == lua_gettop(L));
+  return 0;
+}
+
+static int read_color(lua_State* L) {
+  int top = lua_gettop(L) + 4;
+
+  read_and_validate_buffer_info(L, 1);
+  int32_t x = luaL_checknumber(L, 2);
+  int32_t y = luaL_checknumber(L, 3);
+
+  if (!in_buffer(x, y)) {
+    assert(top == lua_gettop(L));
+    return 0;
+  }
+
+  int i = xytoi(x, y);
+  lua_pushnumber(L, buffer_info.bytes[i]);
+  lua_pushnumber(L, buffer_info.bytes[i + 1]);
+  lua_pushnumber(L, buffer_info.bytes[i + 2]);
+  if (buffer_info.channels == 4) {
+    lua_pushnumber(L, buffer_info.bytes[i + 3]);
+  }
+  assert(top + buffer_info.channels == lua_gettop(L));
+  return buffer_info.channels;
+}
+
 //https://en.wikipedia.org/wiki/Midpoint_circle_algorithm
 static int draw_circle(lua_State* L) {
   int top = lua_gettop(L) + 4;
@@ -426,6 +470,8 @@ static const luaL_reg Module_methods[] = {
   {"fill", fill_texture},
   {"rect", draw_rect},
   {"filled_rect", draw_filled_rect},
+  {"pixel", draw_pixel},
+  {"color", read_color},
   {0, 0}
 };
 

example/canvas.script

@@ -64,6 +64,10 @@ local function color_vector_to_bytes(color)
   return color.x * 255, color.y * 255, color.z * 255, color.w * 255
 end
 
+local function bytes_to_color_vector(r, g, b, a)
+  return vmath.vector4(r / 255, g / 255, b / 255, a / 255)
+end
+
 function on_input(self, action_id, action)
   if action_id == hash("touch") then
     local pos = vmath.vector3(action.x, action.y, 0)
@@ -97,7 +101,10 @@ function on_input(self, action_id, action)
       while length > 0 do
         local r, g, b, a = color_vector_to_bytes(self.current_color)
         if self.current_tool == "pencil" then
-          drawpixels.filled_rect(self.buffer_info, self.touch_pos.x, self.touch_pos.y, 4, 4, r, g, b, a)
+          drawpixels.pixel(self.buffer_info, self.touch_pos.x, self.touch_pos.y, r, g, b, a)
+        elseif self.current_tool == "colorpicker" then
+          local r,g,b,a = drawpixels.color(self.buffer_info, self.touch_pos.x, self.touch_pos.y)
+          self.current_color = bytes_to_color_vector(r, g, b, a)
         elseif self.current_tool == "circle" then
           drawpixels.circle(self.buffer_info, self.touch_pos.x, self.touch_pos.y, 40, r, g, b, a)
         elseif self.current_tool == "line" and self.last_pos and next(self.last_pos) then

example/draw_pixels.atlas

@@ -31,6 +31,9 @@ images {
 images {
   image: "/example/images/line.png"
 }
+images {
+  image: "/example/images/gimp-tool-color-picker.png"
+}
 margin: 0
 extrude_borders: 2
 inner_padding: 0

example/toolbox.gui

@@ -674,7 +674,7 @@ nodes {
 }
 nodes {
   position {
-    x: -46.804
+    x: -64.0
     y: 10.711
     z: 0.0
     w: 1.0
@@ -729,7 +729,7 @@ nodes {
 }
 nodes {
   position {
-    x: -46.804
+    x: -64.0
     y: -34.704
     z: 0.0
     w: 1.0
@@ -784,7 +784,7 @@ nodes {
 }
 nodes {
   position {
-    x: -105.0
+    x: -133.0
     y: 10.0
     z: 0.0
     w: 1.0
@@ -802,7 +802,7 @@ nodes {
     w: 1.0
   }
   size {
-    x: 60.0
+    x: 24.0
     y: 30.0
     z: 0.0
     w: 1.0
@@ -851,8 +851,8 @@ nodes {
     w: 1.0
   }
   scale {
-    x: 1.0
-    y: 1.0
+    x: 0.8
+    y: 0.8
     z: 1.0
     w: 1.0
   }
@@ -863,14 +863,14 @@ nodes {
     w: 1.0
   }
   color {
-    x: 1.0
-    y: 1.0
-    z: 1.0
+    x: 0.3019608
+    y: 0.3019608
+    z: 0.3019608
     w: 1.0
   }
   type: TYPE_TEXT
   blend_mode: BLEND_MODE_ALPHA
-  text: "Clear"
+  text: "CLR"
   font: "system_font"
   id: "text"
   xanchor: XANCHOR_NONE
@@ -957,7 +957,7 @@ nodes {
 }
 nodes {
   position {
-    x: -120.0
+    x: -133.0
     y: -35.0
     z: 0.0
     w: 1.0
@@ -1012,7 +1012,7 @@ nodes {
 }
 nodes {
   position {
-    x: -160.0
+    x: -167.0
     y: -35.0
     z: 0.0
     w: 1.0
@@ -1067,7 +1067,7 @@ nodes {
 }
 nodes {
   position {
-    x: -160.0
+    x: -167.0
     y: 10.0
     z: 0.0
     w: 1.0
@@ -1177,7 +1177,7 @@ nodes {
 }
 nodes {
   position {
-    x: -83.0
+    x: -99.0
     y: -35.0
     z: 0.0
     w: 1.0
@@ -1230,6 +1230,61 @@ nodes {
   template_node_child: false
   size_mode: SIZE_MODE_AUTO
 }
+nodes {
+  position {
+    x: -99.0
+    y: 10.711
+    z: 0.0
+    w: 1.0
+  }
+  rotation {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 1.0
+  }
+  scale {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  size {
+    x: 24.0
+    y: 24.0
+    z: 0.0
+    w: 1.0
+  }
+  color {
+    x: 1.0
+    y: 1.0
+    z: 1.0
+    w: 1.0
+  }
+  type: TYPE_BOX
+  blend_mode: BLEND_MODE_ALPHA
+  texture: "draw_pixels/gimp-tool-color-picker"
+  id: "colorpicker"
+  xanchor: XANCHOR_NONE
+  yanchor: YANCHOR_NONE
+  pivot: PIVOT_CENTER
+  adjust_mode: ADJUST_MODE_FIT
+  parent: "toolbox"
+  layer: ""
+  inherit_alpha: true
+  slice9 {
+    x: 0.0
+    y: 0.0
+    z: 0.0
+    w: 0.0
+  }
+  clipping_mode: CLIPPING_MODE_NONE
+  clipping_visible: true
+  clipping_inverted: false
+  alpha: 1.0
+  template_node_child: false
+  size_mode: SIZE_MODE_AUTO
+}
 material: "/builtins/materials/gui.material"
 adjust_reference: ADJUST_REFERENCE_LEGACY
 max_nodes: 512

example/toolbox.gui_script

@@ -34,6 +34,10 @@ local function use_line()
   msg.post("canvas", "change_tool", { tool = "line" })
 end
 
+local function use_colorpicker()
+  msg.post("canvas", "change_tool", { tool = "colorpicker" })
+end
+
 local function clear()
   msg.post("canvas", "clear")
 end
@@ -51,6 +55,7 @@ function init(self)
   self.nodes[gui.get_node("filled_rect")] = use_filled_rect
   self.nodes[gui.get_node("rotated_rect")] = use_rotated_rect
   self.nodes[gui.get_node("line")] = use_line
+  self.nodes[gui.get_node("colorpicker")] = use_colorpicker
   for i = 1, 10 do
     self.nodes[gui.get_node("color" .. i)] = pick_color
   end