fix transform order and add drawing cascade

3 files changed, 46 insertions, 26 deletions

diff --git a/demo/MeshInstance.lua b/demo/MeshInstance.lua
index 7164f18..a3e6da2 100644
--- a/demo/MeshInstance.lua
+++ b/demo/MeshInstance.lua
@@ -5,11 +5,17 @@ local MeshInstance = {}
 MeshInstance.prototype = {}
 setmetatable(MeshInstance.prototype, { __index = Node.prototype})
 
-MeshInstance.prototype.draw = function(self, shader, camera)
+MeshInstance.prototype.draw = function(self, camera, shader)
+   local shader = shader or self.shader
+   
    honey.shader.set_mat4(shader, 'model', self.transform.array)
    honey.shader.set_mat4(shader, 'view', camera.view.array)
    honey.shader.set_mat4(shader, 'projection', camera.projection.array)
    honey.mesh.draw(self.mesh, shader)
+
+   for _, child in ipairs(self.children) do
+      child:draw(camera)
+   end
 end
 
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -19,13 +25,13 @@ MeshInstance.mt.__index = MeshInstance.prototype
 
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-MeshInstance.new = function(parent, position, rotation, scale, mesh)
+MeshInstance.new = function(parent, position, rotation, scale, mesh, shader)
    local meshinstance = Node.new(parent, position, rotation, scale)
+   meshinstance.mesh = mesh
+   meshinstance.shader = shader
 
    setmetatable(meshinstance, MeshInstance.mt)
 
-   meshinstance.mesh = mesh
-
    return meshinstance
 end
 
diff --git a/demo/Node.lua b/demo/Node.lua
index 08916dd..ffb2aa5 100644
--- a/demo/Node.lua
+++ b/demo/Node.lua
@@ -8,16 +8,16 @@ Node.prototype = {}
 Node.prototype.updateTransform = function(self)
    honey.cglm.mat4.identity(self.transform.array)
 
-   self.transform:scale(self.scale)
+   self.transform:translate(self.position)
 
    self.transform:rotate(Vector.Vec3.ZERO, Vector.Vec3.Z_UNIT, self.rotation:at(2))
    self.transform:rotate(Vector.Vec3.ZERO, Vector.Vec3.Y_UNIT, self.rotation:at(1))
    self.transform:rotate(Vector.Vec3.ZERO, Vector.Vec3.X_UNIT, self.rotation:at(0))
 
-   self.transform:translate(self.position)
+   self.transform:scale(self.scale)
 
    if self.parent ~= nil then
-      self.transform:mul(self.parent.transform, self.transform)
+      self.parent.transform:mul(self.transform, self.transform)
    end
 
    for _, child in ipairs(self.children) do
@@ -25,20 +25,27 @@ Node.prototype.updateTransform = function(self)
    end
 end
 
+Node.prototype.draw = function(self, camera, shader)
+   -- do not draw base nodes, but recursively draw children.
+   for _, child in ipairs(self.children) do
+      child:draw(camera, shader)
+   end
+end
+
 Node.prototype.translate = function(self, translation)
    self.position:add(translation, self.position)
 end
 
 Node.prototype.pitch = function(self, angle)
-   self.rotation:setAt(0, angle)
+   self.rotation:setAt(0, self.rotation:at(0) + angle)
 end
 
 Node.prototype.yaw = function(self, angle)
-   self.rotation:setAt(1, angle)
+   self.rotation:setAt(1, self.rotation:at(1) + angle)
 end
 
 Node.prototype.roll = function(self, angle)
-   self.rotation:setAt(2, angle)
+   self.rotation:setAt(2, self.rotation:at(2) + angle)
 end
 
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/demo/main.lua b/demo/main.lua
index dea393c..e8d3cac 100644
--- a/demo/main.lua
+++ b/demo/main.lua
@@ -1,15 +1,11 @@
 local Vector = require('Vector')
 local Matrix = require('Matrix')
 local FPSCamera = require('FPSCamera')
+local Node = require('Node')
 local ScreenQuad = require('ScreenQuad')
 local MeshInstance = require('MeshInstance')
 FPSCamera.movement_speed = 5
 
-local model = Matrix.Mat4.eye()
-model:rotate(Vector.Vec3.ZERO, Vector.Vec3.Y_UNIT, math.pi)
-model:translate(Vector.Vec3.new{0,0,-2})
-print(model)
-
 honey.input.key.bind(honey.input.key.escape, honey.exit)
 
 local buffer = false
@@ -57,22 +53,34 @@ void main() {
   color = vec4(texture(tex, UV).xyz, 1); 
 } ]]
 
+local sceneRoot = Node.new(nil,
+                           Vector.Vec3.new(),
+                           Vector.Vec3.new(),
+                           Vector.Vec3.new{1,1,1})
+
 local shader = honey.shader.new(vertex_shader, fragment_shader)
-local suzanne = MeshInstance.new(nil,
+local suzanne = MeshInstance.new(sceneRoot,
                                  Vector.Vec3.new{0,0,-3},
                                  Vector.Vec3.new{0,math.pi,0},
-                                 Vector.Vec3.new{1,1,1},
-                                 honey.mesh.load('Suzanne.obj')[1])
+                                 Vector.Vec3.new{0.5,1,0.5},
+                                 honey.mesh.load('Suzanne.obj')[1],
+                                 shader)
 local plane = MeshInstance.new(suzanne,
-                               Vector.Vec3.new{-2,5,0},
+                               Vector.Vec3.new{1,0,0},
                                Vector.Vec3.new{0,0,0},
                                Vector.Vec3.new{1,1,1},
-                               honey.primitives.plane(4,4))
+                               honey.primitives.plane(4,4),
+                               shader)
+local plane2 = MeshInstance.new(suzanne,
+                                Vector.Vec3.new{5,0,0},
+                                Vector.Vec3.new{0,math.pi,0},
+                                Vector.Vec3.new{1,1,1},
+                                honey.primitives.plane(4,4),
+                                shader)
+
 suzanne.update = function(self, dt)
-   local movement = Vector.Vec3.new()
-   movement:add(Vector.Vec3.X_UNIT, movement)
-   movement:muls(dt, movement)
-   self:translate(movement)
+   local angle = dt * math.pi
+   self:yaw(angle)
    self:updateTransform()
 end
 
@@ -94,8 +102,7 @@ end
 
 function draw_suzanne()
    honey.texture.use(tex, 0)
-   suzanne:draw(shader, FPSCamera)
-   plane:draw(shader, FPSCamera)
+   sceneRoot:draw(FPSCamera)
 end
 
 function honey.draw()