rectangle and square shapes

4 files changed, 215 insertions, 7 deletions

diff --git a/drawing.lua b/drawing.lua
index 99d1881..be4952e 100644
--- a/drawing.lua
+++ b/drawing.lua
@@ -63,7 +63,7 @@ function Drawing.draw_shape(left,top, drawing, shape)
     local p1 = drawing.points[shape.p1]
     local p2 = drawing.points[shape.p2]
     love.graphics.line(Drawing.pixels(p1.x)+left,Drawing.pixels(p1.y)+top, Drawing.pixels(p2.x)+left,Drawing.pixels(p2.y)+top)
-  elseif shape.mode == 'polygon' then
+  elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
     local prev = nil
     for _,point in ipairs(shape.vertices) do
       local curr = drawing.points[point]
@@ -82,6 +82,7 @@ function Drawing.draw_shape(left,top, drawing, shape)
     local center = drawing.points[shape.center]
     love.graphics.arc('line', 'open', Drawing.pixels(center.x)+left,Drawing.pixels(center.y)+top, Drawing.pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
   elseif shape.mode == 'deleted' then
+    -- ignore
   else
     print(shape.mode)
     assert(false)
@@ -90,7 +91,9 @@ end
 
 function Drawing.draw_pending_shape(left,top, drawing)
   local shape = drawing.pending
-  if shape.mode == 'freehand' then
+  if shape.mode == nil then
+    -- nothing pending
+  elseif shape.mode == 'freehand' then
     Drawing.draw_shape(left,top, drawing, shape)
   elseif shape.mode == 'line' then
     local mx,my = Drawing.coord(love.mouse.getX()-left), Drawing.coord(love.mouse.getY()-top)
@@ -121,6 +124,34 @@ function Drawing.draw_pending_shape(left,top, drawing)
       prev = curr
     end
     love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, love.mouse.getX(),love.mouse.getY())
+  elseif shape.mode == 'rectangle' then
+    local pmx,pmy = love.mouse.getX(), love.mouse.getY()
+    local first = drawing.points[shape.vertices[1]]
+    if #shape.vertices == 1 then
+      love.graphics.line(Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top, pmx,pmy)
+      return
+    end
+    local second = drawing.points[shape.vertices[2]]
+    local mx,my = Drawing.coord(pmx-left), Drawing.coord(pmy-top)
+    local thirdx,thirdy, fourthx,fourthy = Drawing.complete_rectangle(first.x,first.y, second.x,second.y, mx,my)
+    love.graphics.line(Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top, Drawing.pixels(second.x)+left,Drawing.pixels(second.y)+top)
+    love.graphics.line(Drawing.pixels(second.x)+left,Drawing.pixels(second.y)+top, Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top)
+    love.graphics.line(Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top, Drawing.pixels(fourthx)+left,Drawing.pixels(fourthy)+top)
+    love.graphics.line(Drawing.pixels(fourthx)+left,Drawing.pixels(fourthy)+top, Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top)
+  elseif shape.mode == 'square' then
+    local pmx,pmy = love.mouse.getX(), love.mouse.getY()
+    local first = drawing.points[shape.vertices[1]]
+    if #shape.vertices == 1 then
+      love.graphics.line(Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top, pmx,pmy)
+      return
+    end
+    local second = drawing.points[shape.vertices[2]]
+    local mx,my = Drawing.coord(pmx-left), Drawing.coord(pmy-top)
+    local thirdx,thirdy, fourthx,fourthy = Drawing.complete_square(first.x,first.y, second.x,second.y, mx,my)
+    love.graphics.line(Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top, Drawing.pixels(second.x)+left,Drawing.pixels(second.y)+top)
+    love.graphics.line(Drawing.pixels(second.x)+left,Drawing.pixels(second.y)+top, Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top)
+    love.graphics.line(Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top, Drawing.pixels(fourthx)+left,Drawing.pixels(fourthy)+top)
+    love.graphics.line(Drawing.pixels(fourthx)+left,Drawing.pixels(fourthy)+top, Drawing.pixels(first.x)+left,Drawing.pixels(first.y)+top)
   elseif shape.mode == 'circle' then
     local center = drawing.points[shape.center]
     local mx,my = Drawing.coord(love.mouse.getX()-left), Drawing.coord(love.mouse.getY()-top)
@@ -138,6 +169,9 @@ function Drawing.draw_pending_shape(left,top, drawing)
     shape.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, shape.end_angle)
     local cx,cy = Drawing.pixels(center.x)+left, Drawing.pixels(center.y)+top
     love.graphics.arc('line', 'open', cx,cy, Drawing.pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
+  else
+    print(shape.mode)
+    assert(false)
   end
 end
 
@@ -152,12 +186,15 @@ function Drawing.mouse_pressed(drawing, x,y, button)
   elseif Current_drawing_mode == 'line' or Current_drawing_mode == 'manhattan' then
     local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
     drawing.pending = {mode=Current_drawing_mode, p1=j}
-  elseif Current_drawing_mode == 'polygon' then
+  elseif Current_drawing_mode == 'polygon' or Current_drawing_mode == 'rectangle' or Current_drawing_mode == 'square' then
     local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
     drawing.pending = {mode=Current_drawing_mode, vertices={j}}
   elseif Current_drawing_mode == 'circle' then
     local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
     drawing.pending = {mode=Current_drawing_mode, center=j}
+  else
+    print(Current_drawing_mode)
+    assert(false)
   end
   Lines.current = drawing
 end
@@ -184,6 +221,9 @@ function Drawing.update()
       drawing.pending.target_point.x = mx
       drawing.pending.target_point.y = my
     end
+  else
+    print(Current_drawing_mode)
+    assert(false)
   end
 end
 
@@ -221,10 +261,37 @@ function Drawing.mouse_released(x,y, button)
       elseif Lines.current.pending.mode == 'polygon' then
         local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
         if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
-          local j = Drawing.insert_point(Lines.current.points, mx,my)
+          table.insert(Lines.current.pending.vertices, Drawing.insert_point(Lines.current.points, mx,my))
           table.insert(Lines.current.shapes, Lines.current.pending)
         end
-        table.insert(Lines.current.shapes, Lines.current.pending)
+      elseif Lines.current.pending.mode == 'rectangle' then
+        assert(#Lines.current.pending.vertices <= 2)
+        if #Lines.current.pending.vertices == 2 then
+          local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
+          if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
+            local first = Lines.current.points[Lines.current.pending.vertices[1]]
+            local second = Lines.current.points[Lines.current.pending.vertices[2]]
+            local thirdx,thirdy, fourthx,fourthy = Drawing.complete_rectangle(first.x,first.y, second.x,second.y, mx,my)
+            table.insert(Lines.current.pending.vertices, Drawing.insert_point(Lines.current.points, thirdx,thirdy))
+            table.insert(Lines.current.pending.vertices, Drawing.insert_point(Lines.current.points, fourthx,fourthy))
+            table.insert(Lines.current.shapes, Lines.current.pending)
+          end
+        else
+          -- too few points; draw nothing
+        end
+      elseif Lines.current.pending.mode == 'square' then
+        assert(#Lines.current.pending.vertices <= 2)
+        if #Lines.current.pending.vertices == 2 then
+          local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
+          if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
+            local first = Lines.current.points[Lines.current.pending.vertices[1]]
+            local second = Lines.current.points[Lines.current.pending.vertices[2]]
+            local thirdx,thirdy, fourthx,fourthy = Drawing.complete_square(first.x,first.y, second.x,second.y, mx,my)
+            table.insert(Lines.current.pending.vertices, Drawing.insert_point(Lines.current.points, thirdx,thirdy))
+            table.insert(Lines.current.pending.vertices, Drawing.insert_point(Lines.current.points, fourthx,fourthy))
+            table.insert(Lines.current.shapes, Lines.current.pending)
+          end
+        end
       elseif Lines.current.pending.mode == 'circle' then
         local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
         if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
@@ -239,6 +306,9 @@ function Drawing.mouse_released(x,y, button)
           Lines.current.pending.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, Lines.current.pending.end_angle)
           table.insert(Lines.current.shapes, Lines.current.pending)
         end
+      else
+        print(Lines.current.pending.mode)
+        assert(false)
       end
       Lines.current.pending = {}
       Lines.current = nil
@@ -277,7 +347,37 @@ function Drawing.keychord_pressed(chord)
       drawing.pending.vertices = {drawing.pending.center}
     end
     drawing.pending.mode = 'polygon'
-  elseif love.mouse.isDown('1') and chord == 'p' and Current_drawing_mode == 'polygon' then
+  elseif chord == 'C-r' and not love.mouse.isDown('1') then
+    Current_drawing_mode = 'rectangle'
+  elseif love.mouse.isDown('1') and chord == 'r' then
+    Current_drawing_mode = 'rectangle'
+    local drawing = Drawing.current_drawing()
+    if drawing.pending.mode == 'freehand' then
+      drawing.pending.vertices = {Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)}
+    elseif drawing.pending.mode == 'line' or drawing.pending.mode == 'manhattan' then
+      if drawing.pending.vertices == nil then
+        drawing.pending.vertices = {drawing.pending.p1}
+      end
+    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
+      drawing.pending.vertices = {drawing.pending.center}
+    end
+    drawing.pending.mode = 'rectangle'
+  elseif chord == 'C-s' and not love.mouse.isDown('1') then
+    Current_drawing_mode = 'square'
+  elseif love.mouse.isDown('1') and chord == 's' then
+    Current_drawing_mode = 'square'
+    local drawing = Drawing.current_drawing()
+    if drawing.pending.mode == 'freehand' then
+      drawing.pending.vertices = {Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)}
+    elseif drawing.pending.mode == 'line' or drawing.pending.mode == 'manhattan' then
+      if drawing.pending.vertices == nil then
+        drawing.pending.vertices = {drawing.pending.p1}
+      end
+    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
+      drawing.pending.vertices = {drawing.pending.center}
+    end
+    drawing.pending.mode = 'square'
+  elseif love.mouse.isDown('1') and chord == 'p' and (Current_drawing_mode == 'polygon' or Current_drawing_mode == 'rectangle' or Current_drawing_mode == 'square') then
     local drawing = Drawing.current_drawing()
     local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
     local j = Drawing.insert_point(drawing.points, mx,my)
@@ -397,6 +497,62 @@ function Drawing.keychord_pressed(chord)
   end
 end
 
+function Drawing.complete_rectangle(firstx,firsty, secondx,secondy, x,y)
+  if firstx == secondx then
+    local thirdx = y
+    local thirdy = secondy
+    love.graphics.line(Drawing.pixels(secondx)+left,Drawing.pixels(secondy)+top, Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top)
+    love.graphics.line(Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top, Drawing.pixels(thirdx)+left,Drawing.pixels(firsty)+top)
+    return thirdx,thirdy, thirdx,firsty
+  end
+  if firsty == secondy then
+    local thirdx = secondx
+    local thirdy = y
+    love.graphics.line(Drawing.pixels(secondx)+left,Drawing.pixels(secondy)+top, Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top)
+    love.graphics.line(Drawing.pixels(thirdx)+left,Drawing.pixels(thirdy)+top, Drawing.pixels(firstx)+left,Drawing.pixels(thirdy)+top)
+    return
+  end
+  local first_slope = (secondy-firsty)/(secondx-firstx)
+  -- slope of second edge:
+  --    -1/first_slope
+  -- equation of line containing the second edge:
+  --    y-secondy = -1/first_slope*(x-secondx)
+  -- => 1/first_slope*x + y + (- secondy - secondx/first_slope) = 0
+  -- now we want to find the point on this line that's closest to the mouse pointer.
+  -- https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line#Line_defined_by_an_equation
+  local a = 1/first_slope
+  local c = -secondy - secondx/first_slope
+  local thirdx = ((x-a*y) - a*c) / (a*a + 1)
+  local thirdy = (a*(-x + a*y) - c) / (a*a + 1)
+  -- slope of third edge = first_slope
+  -- equation of line containing third edge:
+  --     y - thirdy = first_slope*(x-thirdx)
+  --  => -first_slope*x + y + (-thirdy + thirdx*first_slope) = 0
+  -- now we want to find the point on this line that's closest to the first point
+  local a = -first_slope
+  local c = -thirdy + thirdx*first_slope
+  local fourthx = ((firstx-a*firsty) - a*c) / (a*a + 1)
+  local fourthy = (a*(-firstx + a*firsty) - c) / (a*a + 1)
+  return thirdx,thirdy, fourthx,fourthy
+end
+
+function Drawing.complete_square(firstx,firsty, secondx,secondy, x,y)
+  -- use x,y only to decide which side of the first edge to complete the square on
+  local deltax = secondx-firstx
+  local deltay = secondy-firsty
+  local thirdx = secondx+deltay
+  local thirdy = secondy-deltax
+  if not geom.same_side(firstx,firsty, secondx,secondy, thirdx,thirdy, x,y) then
+    deltax = -deltax
+    deltay = -deltay
+    thirdx = secondx+deltay
+    thirdy = secondy-deltax
+  end
+  local fourthx = firstx+deltay
+  local fourthy = firsty-deltax
+  return thirdx,thirdy, fourthx,fourthy
+end
+
 function Drawing.current_drawing()
   local x, y = love.mouse.getX(), love.mouse.getY()
   for _,drawing in ipairs(Lines) do
diff --git a/geom.lua b/geom.lua
index 20cc5dd..7dd6628 100644
--- a/geom.lua
+++ b/geom.lua
@@ -7,7 +7,7 @@ function geom.on_shape(x,y, drawing, shape)
     return geom.on_line(x,y, drawing, shape)
   elseif shape.mode == 'manhattan' then
     return x == drawing.points[shape.p1].x or y == drawing.points[shape.p1].y
-  elseif shape.mode == 'polygon' then
+  elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
     return geom.on_polygon(x,y, drawing, shape)
   elseif shape.mode == 'circle' then
     local center = drawing.points[shape.center]
@@ -82,6 +82,28 @@ function geom.on_polygon(x,y, drawing, shape)
   return geom.on_line(x,y, drawing, {p1=shape.vertices[1], p2=shape.vertices[#shape.vertices]})
 end
 
+-- are (x3,y3) and (x4,y4) on the same side of the line between (x1,y1) and (x2,y2)
+function geom.same_side(x1,y1, x2,y2, x3,y3, x4,y4)
+  if x1 == x2 then
+    return math.sign(x3-x1) == math.sign(x4-x1)
+  end
+  if y1 == y2 then
+    return math.sign(y3-y1) == math.sign(y4-y1)
+  end
+  local m = (y2-y1)/(x2-x1)
+  return math.sign(m*(x3-x1) + y1-y3) == math.sign(m*(x4-x1) + y1-y4)
+end
+
+function math.sign(x)
+  if x > 0 then
+    return 1
+  elseif x == 0 then
+    return 0
+  elseif x < 0 then
+    return -1
+  end
+end
+
 function geom.angle_with_hint(x1, y1, x2, y2, hint)
   local result = geom.angle(x1,y1, x2,y2)
   if hint then
diff --git a/help.lua b/help.lua
index 0feaba1..f979b2f 100644
--- a/help.lua
+++ b/help.lua
@@ -32,6 +32,14 @@ function draw_help_without_mouse_pressed(drawing)
     love.graphics.print("* Press 'ctrl+g' to switch to drawing polygons", 16+30,y, 0, Zoom)
     y = y+15*Zoom
   end
+  if Current_drawing_mode ~= 'rectangle' then
+    love.graphics.print("* Press 'ctrl+r' to switch to drawing rectangles", 16+30,y, 0, Zoom)
+    y = y+15*Zoom
+  end
+  if Current_drawing_mode ~= 'square' then
+    love.graphics.print("* Press 'ctrl+s' to switch to drawing squares", 16+30,y, 0, Zoom)
+    y = y+15*Zoom
+  end
   love.graphics.print("* Press 'ctrl+=' or 'ctrl+-' to Zoom in or out", 16+30,y, 0, Zoom)
   y = y+15*Zoom
   love.graphics.print("* Press 'ctrl+0' to reset Zoom", 16+30,y, 0, Zoom)
@@ -90,6 +98,14 @@ function draw_help_with_mouse_pressed(drawing)
     love.graphics.print("* Press 'g' to switch to drawing polygons", 16+30,y, 0, Zoom)
     y = y+15*Zoom
   end
+  if Current_drawing_mode ~= 'rectangle' then
+    love.graphics.print("* Press 'g' to switch to drawing rectangles", 16+30,y, 0, Zoom)
+    y = y+15*Zoom
+  end
+  if Current_drawing_mode ~= 'square' then
+    love.graphics.print("* Press 'g' to switch to drawing squares", 16+30,y, 0, Zoom)
+    y = y+15*Zoom
+  end
   love.graphics.setColor(0,0.5,0, 0.1)
   love.graphics.rectangle('fill', 16,drawing.y, Drawing_width, math.max(Drawing.pixels(drawing.h),y-drawing.y))
 end
diff --git a/icons.lua b/icons.lua
index 0d05d09..8bfa67e 100644
--- a/icons.lua
+++ b/icons.lua
@@ -40,6 +40,20 @@ function icon.polygon(x, y)
   love.graphics.line(x+4,y+12, x+8,y+2)
 end
 
+function icon.rectangle(x, y)
+  love.graphics.line(x+4,y+8, x+4,y+16)
+  love.graphics.line(x+4,y+16, x+16,y+16)
+  love.graphics.line(x+16,y+16, x+16,y+8)
+  love.graphics.line(x+16,y+8, x+4,y+8)
+end
+
+function icon.square(x, y)
+  love.graphics.line(x+6,y+6, x+6,y+16)
+  love.graphics.line(x+6,y+16, x+16,y+16)
+  love.graphics.line(x+16,y+16, x+16,y+6)
+  love.graphics.line(x+16,y+6, x+6,y+6)
+end
+
 function icon.circle(x, y)
   love.graphics.circle('line', x+10,y+10, 8)
 end