feat: add kind parameter for beginShape function (supporting LINES, POINTS, TRIANGLE_FAN, TRIANGLE_STRIP, and TRIANGLES)

L5.lua

@@ -824,6 +824,12 @@ function defaults()
   SIZEALL = "sizeall"
   NO = "no"
   HAND = "hand"
+  -- beginShape kinds
+  POINTS = "points"
+  LINES = "lines"
+  TRIANGLES = "triangles"
+  TRIANGLE_FAN = "fan"
+  TRIANGLE_STRIP = "strip"
 
   -- global user vars - can be read by user but shouldn't be altered by user
   key = "" --default, overriden with key presses detected in love.update(dt)
@@ -893,6 +899,12 @@ function define_env_globals()
   L5_env.pixelsLoaded = false
   -- custom shape drawing 
   L5_env.vertices = {}
+  L5_env.kind = nil
+  L5_env.shapeKinds = {[POINTS] = true, [LINES] = true, [TRIANGLES]=true, [TRIANGLE_FAN]=true, [TRIANGLE_STRIP]=true}
+  L5_env.mesh = love.graphics.newMesh(
+    {{"VertexPosition", "float", 2}},
+    4096, "triangles", "dynamic"
+  ) -- reusable mesh for non-texture shapes
   -- custom texture mesh
   L5_env.currentTexture = nil
   L5_env.useTexture = false
@@ -2301,10 +2313,27 @@ function textureWrap(_mode)
     end
 end
 
-function beginShape()
+function beginShape(...)
+
+  local n = select('#' , ...)
+  if(n > 1) then
+     error("beginShape(kind) accepts at most one argument", 2)
+  end
+
+  local _kind = select(1, ...)
+
+  if n == 0 then
+    _kind = nil
+  elseif _kind == nil then
+    error("This kind is not defined (undefined variable passed)")
+  elseif not L5_env.shapeKinds[_kind] then -- if any other type is passed
+    error("Invalid kind: " .. tostring(_kind))
+  end
+
   -- reset custom shape vertices table
   L5_env.vertices = {}
   L5_env.useTexture = false
+  L5_env.kind = _kind
 end
 
 function vertex(_x, _y, _u, _v)
@@ -2328,43 +2357,161 @@ function endShape(_close)
   -- no vertices, early exit
   if #L5_env.vertices == 0 then return end
 
+  -- helper function to convert flat {x,y,x,y...} to {{x,y},{x,y}...}
+  local function toVertTable(verts)
+    if type(verts[1]) == "number" then
+      local converted = {}
+      for i = 1, #verts, 2 do
+        converted[#converted+1] = {verts[i], verts[i+1]}
+      end
+      return converted
+    end
+    return verts
+  end
+
+  -- draw points
+  if L5_env.kind == POINTS then
+    local r, g, b, a = love.graphics.getColor()
+    love.graphics.setColor(unpack(L5_env.stroke_color))
+    for i = 1, #L5_env.vertices, 2 do
+      love.graphics.points(L5_env.vertices[i], L5_env.vertices[i+1])
+    end
+    love.graphics.setColor(r, g, b, a)
+
+  -- draw unconnected lines
+  elseif L5_env.kind == LINES then
+    local r, g, b, a = love.graphics.getColor()
+    love.graphics.setColor(unpack(L5_env.stroke_color))
+    for i = 1, #L5_env.vertices - 2, 4 do
+      love.graphics.line(
+        L5_env.vertices[i], L5_env.vertices[i+1],
+        L5_env.vertices[i+2], L5_env.vertices[i+3]
+      )
+    end
+    love.graphics.setColor(r, g, b, a)
+
+  -- draw separated triangles
+  elseif L5_env.kind == TRIANGLES then
+    local verts = toVertTable(L5_env.vertices)
+    if L5_env.useTexture and L5_env.currentTexture then
+      local mesh = love.graphics.newMesh(verts, TRIANGLES)
+      mesh:setTexture(L5_env.currentTexture)
+      L5_env.currentTexture:setWrap(L5_env.textureWrap, L5_env.textureWrap)
+      love.graphics.draw(mesh)
+    else
+      if L5_env.fill_mode == "fill" then
+        L5_env.mesh:setVertices(verts, 1, #verts)
+        L5_env.mesh:setDrawMode("triangles")
+        L5_env.mesh:setDrawRange(1, #verts)
+        love.graphics.draw(L5_env.mesh)
+      end
+      local r, g, b, a = love.graphics.getColor()
+      love.graphics.setColor(unpack(L5_env.stroke_color))
+      for i = 1, #verts, 3 do
+        local v1, v2, v3 = verts[i], verts[i+1], verts[i+2]
+        if v1 == nil or v2 == nil or v3 == nil then break end
+        love.graphics.line(v1[1],v1[2], v2[1],v2[2])
+        love.graphics.line(v2[1],v2[2], v3[1],v3[2])
+        love.graphics.line(v3[1],v3[2], v1[1],v1[2])
+      end
+      love.graphics.setColor(r, g, b, a)
+    end
+
+  -- draw triangle strip
+  elseif L5_env.kind == TRIANGLE_STRIP then
+    local verts = toVertTable(L5_env.vertices)
+    if L5_env.useTexture and L5_env.currentTexture then
+      local mesh = love.graphics.newMesh(verts, TRIANGLE_STRIP)
+      mesh:setTexture(L5_env.currentTexture)
+      L5_env.currentTexture:setWrap(L5_env.textureWrap, L5_env.textureWrap)
+      love.graphics.draw(mesh)
+    else
+      if L5_env.fill_mode == "fill" then
+        L5_env.mesh:setVertices(verts, 1, #verts)
+        L5_env.mesh:setDrawMode("strip")
+        L5_env.mesh:setDrawRange(1, #verts)
+        love.graphics.draw(L5_env.mesh)
+      end
+      local r, g, b, a = love.graphics.getColor()
+      love.graphics.setColor(unpack(L5_env.stroke_color))
+      for i = 1, #verts-2 do
+        local v1, v2, v3 = verts[i], verts[i+1], verts[i+2]
+        if v1 == nil or v2 == nil or v3 == nil then break end
+        love.graphics.line(v1[1],v1[2], v2[1],v2[2])
+        love.graphics.line(v2[1],v2[2], v3[1],v3[2])
+        love.graphics.line(v3[1],v3[2], v1[1],v1[2])
+      end
+      love.graphics.setColor(r, g, b, a)
+    end
+
+  -- draw triangles centered around the first vertex
+  elseif L5_env.kind == TRIANGLE_FAN then
+    local verts = toVertTable(L5_env.vertices)
+    if L5_env.useTexture and L5_env.currentTexture then
+      local mesh = love.graphics.newMesh(verts, TRIANGLE_FAN)
+      mesh:setTexture(L5_env.currentTexture)
+      L5_env.currentTexture:setWrap(L5_env.textureWrap, L5_env.textureWrap)
+      love.graphics.draw(mesh)
+    else
+      if L5_env.fill_mode == "fill" then
+        L5_env.mesh:setVertices(verts, 1, #verts)
+        L5_env.mesh:setDrawMode("fan")
+        L5_env.mesh:setDrawRange(1, #verts)
+        love.graphics.draw(L5_env.mesh)
+      end
+      local r, g, b, a = love.graphics.getColor()
+      love.graphics.setColor(unpack(L5_env.stroke_color))
+      for i = 2, #verts-1 do
+        local v1, v2, v3 = verts[1], verts[i], verts[i+1]
+        if v1 == nil or v2 == nil or v3 == nil then break end
+        love.graphics.line(v1[1],v1[2], v2[1],v2[2])
+        love.graphics.line(v2[1],v2[2], v3[1],v3[2])
+        love.graphics.line(v3[1],v3[2], v1[1],v1[2])
+      end
+      love.graphics.setColor(r, g, b, a)
+    end
+
+  -- polygon fallback (kind == nil) 
   -- if texture() triangulate fan mesh - convex assumed
-  if L5_env.useTexture and L5_env.currentTexture then
-    local mesh = love.graphics.newMesh(L5_env.vertices, "fan")
-    mesh:setTexture(L5_env.currentTexture)
-    L5_env.currentTexture:setWrap(L5_env.textureWrap, L5_env.textureWrap)
-    love.graphics.draw(mesh)
   else
-    -- triangulate handles concave shapes but errors on self-intersecting polygons
-    if L5_env.fill_mode == "fill" then
-      local ok, triangles = pcall(love.math.triangulate, L5_env.vertices)
-      if ok then
-        local meshVerts = {}
-        for _, tri in ipairs(triangles) do
-          for i = 1, 6, 2 do
-            meshVerts[#meshVerts+1] = {tri[i], tri[i+1]}
+    if L5_env.useTexture and L5_env.currentTexture then
+      local mesh = love.graphics.newMesh(L5_env.vertices, "fan")
+      mesh:setTexture(L5_env.currentTexture)
+      L5_env.currentTexture:setWrap(L5_env.textureWrap, L5_env.textureWrap)
+      love.graphics.draw(mesh)
+    else
+      -- triangulate handles concave shapes but errors on self-intersecting polygons
+      if L5_env.fill_mode == "fill" then
+        local ok, triangles = pcall(love.math.triangulate, L5_env.vertices)
+        if ok then
+          local meshVerts = {}
+          for _, tri in ipairs(triangles) do
+            for i = 1, 6, 2 do
+              meshVerts[#meshVerts+1] = {tri[i], tri[i+1]}
+            end
           end
+          L5_env.mesh:setVertices(meshVerts, 1, #meshVerts)
+          L5_env.mesh:setDrawMode("triangles")
+          L5_env.mesh:setDrawRange(1, #meshVerts)
+          love.graphics.draw(L5_env.mesh)
+        else
+          love.graphics.polygon("fill", L5_env.vertices)
         end
-        local mesh = love.graphics.newMesh(meshVerts, "triangles")
-        love.graphics.draw(mesh)
+      end
+      local r, g, b, a = love.graphics.getColor()
+      love.graphics.setColor(unpack(L5_env.stroke_color))
+      if _close == CLOSE then
+        local verts = L5_env.vertices
+        -- draw all segments
+        love.graphics.line(verts[1], verts[2], unpack(verts, 3, #verts))
+        -- close by drawing back to start
+        love.graphics.line(verts[#verts-1], verts[#verts], verts[1], verts[2])
       else
-        love.graphics.polygon("fill", L5_env.vertices)
+        -- continuous lines, doesn't close the last two segments aka OPEN
+        love.graphics.line(L5_env.vertices)
       end
+      love.graphics.setColor(r, g, b, a)
     end
-    local r, g, b, a = love.graphics.getColor()
-    love.graphics.setColor(unpack(L5_env.stroke_color))
-    if _close == CLOSE then
-      local verts = L5_env.vertices
-      -- draw all segments
-      love.graphics.line(verts[1], verts[2], 
-	unpack(verts, 3, #verts))
-      -- close by drawing back to start
-      love.graphics.line(verts[#verts-1], verts[#verts], verts[1], verts[2])    
-    else
-      -- continuous lines, doesn't close the last two segments aka OPEN
-      love.graphics.line(L5_env.vertices)
-    end
-    love.graphics.setColor(r, g, b, a)
   end
 end
 

TODO.txt

@@ -57,7 +57,7 @@
 * [X] ellipseMode doesn't seem to work? 
 * [X] imageMode(): add CORNERS mode
 * [X] add custom shape creation via createShape() (processing) / beginShape() (p5.js), vertex() and endShape() (using love2d polygon - pass vertices as table?)
-* [ ] improve beginShape to get feature parity with p5-processing with `kind`? at the very least, basic shape drawing should match basic examples on reference page.
+* [ ] Add QUADS, QUAD_STRIP, TESS support for kind parameter in beginShape
 
 ## Filter
 

examples/beginShapeLines.lua

@@ -0,0 +1,14 @@
+require("L5")
+
+function setup() 
+  size(400, 400)
+  windowTitle("beginShape(LINES) example")
+
+  fill(0)
+  beginShape(LINES)
+  for i=0,10 do
+    vertex(random(width),random(height))
+  end
+  endShape()
+  describe("custom shape with beginShape(LINES) function, vertices and endShape()")
+end

examples/beginShapePoints.lua

@@ -0,0 +1,14 @@
+require("L5")
+
+function setup() 
+  size(400, 400)
+  windowTitle("beginShape(POINTS) example")
+
+  fill(0)
+  beginShape(POINTS)
+  for i=0,10 do
+    vertex(random(width),random(height))
+  end
+  endShape()
+  describe("custom shape with beginShape(POINTS) function, vertices and endShape()")
+end

examples/beginShapeTriangleFan.lua

@@ -0,0 +1,24 @@
+require("L5")
+
+function setup() 
+  size(400, 400)
+  windowTitle("beginShape(TRIANGLE_FAN) example")
+
+  fill(150, 200, 255)
+  stroke(51)
+  strokeWeight(5)
+
+  beginShape(TRIANGLE_FAN)
+  vertex(200, 200)  -- center
+  vertex(200, 50)   -- top
+  vertex(320, 110)
+  vertex(370, 250)
+  vertex(280, 370)
+  vertex(120, 370)
+  vertex(30,  250)
+  vertex(80,  110)
+  vertex(200, 50)
+  endShape()
+
+  describe("octagon drawn with beginShape(TRIANGLE_FAN) from a center point, with stroke")
+end

examples/beginShapeTriangleStrip.lua

@@ -0,0 +1,23 @@
+require("L5")
+
+function setup()
+  size(400, 400)
+  windowTitle("beginShape(TRIANGLE_STRIP) example")
+
+  fill(255, 180, 100)
+  stroke(51)
+  strokeWeight(2)
+
+  beginShape(TRIANGLE_STRIP)
+  vertex(50,  100)
+  vertex(50,  300)
+  vertex(150, 50)
+  vertex(150, 300)
+  vertex(250, 100)
+  vertex(250, 300)
+  vertex(350, 50)
+  vertex(350, 300)
+  endShape()
+
+  describe("ribbon of triangles drawn with beginShape(TRIANGLE_STRIP), with stroke")
+end

examples/beginShapeTriangles.lua

@@ -0,0 +1,23 @@
+require("L5")
+
+function setup() 
+  size(400, 400)
+  windowTitle("beginShape(TRIANGLES) example")
+
+  fill(0)
+  beginShape(TRIANGLES);
+
+  -- Left triangle
+  vertex(30, 75);
+  vertex(40, 20);
+  vertex(50, 75);
+
+  -- Right triangle
+  vertex(60, 20);
+  vertex(70, 75);
+  vertex(80, 20);
+
+  endShape();
+
+  describe("custom shape with beginShape(TRIANGLES) function, vertices and endShape()")
+end

examples/beginShapeTrianglsWithTexture.lua

@@ -0,0 +1,23 @@
+require("L5")
+
+function setup()
+  size(400, 400)
+  windowTitle("texture() example")
+  textureMode(NORMAL)
+
+  cat = loadImage("examples/assets/cat.png")
+
+  beginShape(TRIANGLES)
+  texture(cat)
+  vertex(50,  100, 0,    0.2)
+  vertex(50,  300, 0,    1)
+  vertex(150, 50,  0.33, 0)
+  vertex(150, 300, 0.33, 1)
+  vertex(250, 100, 0.67, 0.2)
+  vertex(250, 300, 0.67, 1)
+  vertex(350, 50,  1,    0)
+  vertex(350, 300, 1,    1)
+  endShape()
+
+  describe("Wrapping a mesh texture around a custom shape with coordinates specified with u,v")
+end