[nacltoons] Use box2d sensors to detect collisions.

nacltoons/data/res/loader.lua

Index: nacltoons/data/res/loader.lua
diff --git a/nacltoons/data/res/loader.lua b/nacltoons/data/res/loader.lua
index 63d5a338937931c712d76d7d616398b70ab3bb44..c1adadde26d537b5868a21be26429c4274679986 100644
--- a/nacltoons/data/res/loader.lua
+++ b/nacltoons/data/res/loader.lua
@@ -38,22 +38,23 @@ local function LoadGame(filename)
     return game
 end
 
-local function AddShapeToBody(body, shape)
+local function AddShapeToBody(body, shape, sensor)
     Log('adding fixture')
     local fixture_def = b2FixtureDef:new_local()
     fixture_def.shape = shape
     fixture_def.density = 1.0
     fixture_def.friction = 0.5
     fixture_def.restitution = 0.3
+    fixture_def.isSensor = sensor
     Log('adding fixture 2')
     body:CreateFixture(fixture_def)
     Log('adding fixture done')
 end
 
-local function AddSphereToBody(body, radius)
+local function AddSphereToBody(body, radius, sensor)
     local shape = b2CircleShape:new_local()
     shape.m_radius = ScreenToWorld(radius)
-    AddShapeToBody(body, shape)
+    AddShapeToBody(body, shape, sensor)
 end
 
 --- Create a fix pivot point between the world and the given object.
@@ -91,8 +92,10 @@ local function CreateLine(world, brush, from, to, object)
     end
 
     -- calculate thickness based on brush sprite size
-    local brush_size = brush:getContentSize();
-    local thinkness = math.max(brush_size.height/2, brush_size.width/2);
+    local brush_tex = brush:getTexture()
+    local brush_size = brush_tex:getContentSizeInPixels()
+    local thickness = math.max(brush_size.height/2, brush_size.width/2);
+    Log('thickness: '..thickness)
 
     -- calculate length and angle of line based on start and end points
     local length = ccpDistance(from, to);
@@ -105,7 +108,7 @@ local function CreateLine(world, brush, from, to, object)
     local center = b2Vec2:new_local(ScreenToWorld(dist_x/2),
                                     ScreenToWorld(dist_y/2))
     local shape = b2PolygonShape:new_local()
-    shape:SetAsBox(ScreenToWorld(length/2), ScreenToWorld(thinkness),
+    shape:SetAsBox(ScreenToWorld(length/2), ScreenToWorld(thickness),
                    center, angle)
     local fixture_def = b2FixtureDef:new_local()
     fixture_def.shape = shape
@@ -115,24 +118,22 @@ local function CreateLine(world, brush, from, to, object)
     body:CreateFixture(fixture_def)
 
     -- Now create a visible CCPhysicsSprite that the body is attached to
-    local brush_tex = brush:getTexture()
     local sprite = CCPhysicsSprite:createWithTexture(brush_tex)
     sprite:setB2Body(body)
     sprite:setPTMRatio(PTM_RATIO)
 
     -- And add a sequence of non-physics sprites as children of the first
     local dist = CCPointMake(dist_x, dist_y)
-    local num_children = length / thinkness
+    local num_children = length / thickness
     local inc_x = dist_x / num_children
     local inc_y = dist_y / num_children
-    local child_location = CCPointMake(0, 0)
-    for i = 2,num_children do
+    local child_location = CCPointMake(thickness, thickness)
+    for i = 1,num_children do

[binji, 2013/03/04 19:31:13]

won't this draw the 1st sprite twice?

[Sam Clegg, 2013/03/04 20:08:18]

The initial physics sprite is drawn at the line origin.

The first thing in the look is to add "inc_x" and "inc_y" to the location, so it
won't draw in the same place.

That being said, the two ends of the line are not being 
drawn in exactly the same way, so there is certainly a bug
here somewhere (just a minor discrepancy between the physics
and drawing).

         child_location.x = child_location.x + inc_x
         child_location.y = child_location.y + inc_y
 
         local child_sprite = CCSprite:createWithTexture(brush_tex)
         child_sprite:setPosition(child_location)
-        child_sprite:setAnchorPoint(CCPointMake(0, 0))
         sprite:addChild(child_sprite)
     end
 
@@ -145,17 +146,19 @@ local function PointFromLua(origin, point)
     return CCPointMake(point[1] + origin.x, point[2] + origin.y)
 end
 
---- Create ball, a physics object
-local function CreateTheBall(image, location, b2d_world)
+--- Create a physics sprite at a fiven location with a given image
+local function CreatePhysicsSprite(b2d_world, location, image, sensor)
     Log('goal: '..location.x..'x'..location.y)
     local ball = CCPhysicsSprite:create(image)
     local body_def = b2BodyDef:new_local()
-    body_def.type = b2_dynamicBody
+    if not sensor then
+        body_def.type = b2_dynamicBody
+    end
     local body = b2d_world:CreateBody(body_def)
     ball:setB2Body(body)
     ball:setPTMRatio(PTM_RATIO)
     ball:setPosition(location)
-    AddSphereToBody(body, ball:boundingBox().size.height/2)
+    AddSphereToBody(body, ball:boundingBox().size.height/2, sensor)
     return ball
 end
 
@@ -171,31 +174,28 @@ local function LoadLevel(game, level_number)
     local origin = CCDirector:sharedDirector():getVisibleOrigin()
     local layer = PhysicsLayer:GetCurrent()
     local world = layer:GetWorld()
-    local cache = CCTextureCache:sharedTextureCache()
 
-    local ball = CreateTheBall(game.ball_image,
-                               PointFromLua(origin, level.start), world)
+    local ball = CreatePhysicsSprite(world, PointFromLua(origin, level.start),
+                                     game.ball_image, false)
     layer:addChild(ball, 1, tags.BALL)
 
     -- Load brush image
-    game.brush_image = cache:addImage(game.brush_image)
-    local brush = CCSprite:createWithTexture(game.brush_image)
-    brush:setVisible(false)
+    local brush = CCSpriteBatchNode:create(game.brush_image)
+    -- brush:setVisible(false)
     layer:addChild(brush, 1, tags.BRUSH)
 
     -- Create goal and stars
     Log('goal: '..level.goal[1]..'x'..level.goal[2])
-    local goal = CCSprite:create(game.goal_image)
-    goal:setPosition(PointFromLua(origin, level.goal))
+    local goal = CreatePhysicsSprite(world, PointFromLua(origin, level.goal),
+                                     game.goal_image, true)
     layer:addChild(goal, 1, tags.GOAL)
 
-    game.star_image = cache:addImage(game.star_image)
     for i, star in ipairs(level.stars) do
-        local sprite = CCSprite:createWithTexture(game.star_image)
+        local sprite = CreatePhysicsSprite(world, PointFromLua(origin, star),
+                                           game.star_image, true)
         local tag = tags.STAR1 + i - 1
         Log('loading star [tag='..tag..']: '..star[1]..'x'..star[2])
         layer:addChild(sprite, 1, tag)
-        sprite:setPosition(PointFromLua(origin, star))
     end
 
     -- Load fixtures
@@ -206,11 +206,13 @@ local function LoadLevel(game, level_number)
             object.anchor = PointFromLua(origin, object.anchor)
         end
         local line = CreateLine(world, brush, start, finish, object)
-        layer:addChild(line, 1, tags.OBJECTS_START+i-1)
+        brush:addChild(line, 1, tags.OBJECTS_START+i-1)
     end
-
-    game.background = cache:addImage(game.background_image)
 end
 
-game = LoadGame('sample_game/game.lua')
+-- Global variables that can be used in the lua data files.
+height = 600
+width = 800
+
+local game = LoadGame('sample_game/game.lua')
 LoadLevel(game, 1)