From 20f27d6eaee89e6b4950ccf9b3a96ab1e59f9d51 Mon Sep 17 00:00:00 2001
From: sanine <sanine.not@pm.me>
Date: Fri, 7 Apr 2023 00:13:15 -0500
Subject: move new render/transform systems into ecs-systems.lua

---
 honey/ecs-systems.lua | 140 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 91 insertions(+), 49 deletions(-)

(limited to 'honey/ecs-systems.lua')

diff --git a/honey/ecs-systems.lua b/honey/ecs-systems.lua
index 5dec159..18f50a8 100644
--- a/honey/ecs-systems.lua
+++ b/honey/ecs-systems.lua
@@ -1,4 +1,6 @@
 local ecs = require 'honey.ecs'
+local gl = honey.gl
+local glfw = honey.glfw
 
 
 local module = {}
@@ -9,67 +11,107 @@ setfenv(1, module)
 
 --===== transform cascading =====--
 
-local function recursiveComputeTransform(entity)
-	if entity._transformComputed then 
-		return entity._transform 
-	end
-	if entity.parent == false then
-		entity._transformComputed = true
-		entity._transform = entity.transform
-		return entity.transform
-	end
-
-	entity._transformComputed = true
-	local parentTransform = recursiveComputeTransform(entity.parent)
-	entity._transform = parentTransform * entity.transform
-	return entity._transform
+transform = function(params)
+	return {
+		db = params.db,
+		update = function(self, dt)
+			local entities = self.db:queryComponent("transform")
+	
+			-- prepare transforms
+			for id, transform in pairs(entities) do
+				transform._visited = false
+			end
+	
+			-- helper function
+			local function recursiveTransform(transform)
+				if transform._visited then
+					return transform._matrix
+				end
+	
+				if not transform.parent then
+					transform._matrix = transform.matrix
+				else
+					local parentTransform = self.db:getComponent(transform.parent, "transform")
+					local parentMatrix = recursiveTransform(parentTransform)
+					transform._matrix = parentMatrix * transform.matrix
+				end
+				transform._visited = true
+				return transform._matrix
+			end
+	
+			-- compute transforms
+			for id, transform in pairs(entities) do
+				recursiveTransform(transform)
+			end
+		end,
+		priority = 0,
+	}
 end
 
--- update transforms
-transformCascade = {
-	filter=ecs.Filter.AND{"transform", "parent"},
-	prepareEntity=function(self, entity)
-		entity._transform = nil
-		entity._transformComputed = false
-	end,
-	update=function(self, entity, dt)
-		recursiveComputeTransform(entity)
-	end,
-	priority=98,
-}
 
 
 --===== rendering =====--
 
-function renderCam(camera, priority)
-	local priority = priority or 99
+function renderCamera(params) 
 	return {
-		filter=ecs.Filter.AND{"mesh", "shader", "transform"},
-		update=function(self, entity, dt)
-			entity.shader:use()
-			entity.shader:configure{
-				matrix={
-					model=entity._transform,
-					view=camera.view,
-					projection=camera.projection,
-				},
-			}
-			entity.mesh:drawElements()
+		camera = params.camera,
+		db = params.db,
+		priority = params.priority or 99,
+		update = function(self, dt)
+			local cameraParams = self.db:getComponent(self.camera, "camera")
+			local cameraTransform = self.db:getComponent(self.camera, "transform")
+			local view
+			if cameraTransform then
+				view = cameraTransform._matrix
+			else
+				view = Mat4():identity()
+			end
+	
+			local entities = self.db:queryComponent("renderMesh")
+			for entity, tbl in pairs(entities) do
+				-- get shader
+				local shader = honey.shader.loadShader(tbl.shader.vertex, tbl.shader.fragment)
+				shader:use()
+	
+				-- bind textures
+				local texOffset = 0
+				for name, texTbl in pairs(tbl.textures or {}) do
+					local texture = honey.image.loadImage(texTbl.filename, texTbl.params)
+					gl.BindTexture(gl.TEXTURE_2D + texOffset, texture.texture)
+					shader:setInt(name, texOffset)
+					texOffset = texOffset + 1
+				end
+	
+				-- configure default uniforms
+				local query = self.db:getComponent(entity, "transform")
+				local model = (query and query._matrix) or Mat4():identity()
+				shader:configure{
+					float={
+						time=glfw.GetTime(),
+					},
+					matrix={
+						view=view,
+						projection=cameraParams.projection,
+						model=model,
+					},
+				}
+	
+				-- draw mesh
+				local mesh = honey.mesh.loadMesh(tbl.mesh.filename, tbl.mesh.index)
+				mesh:drawElements()
+	
+				-- unbind textures
+				for i=0,texOffset-1 do
+					gl.BindTexture(gl.TEXTURE_2D + i, 0)
+				end
+			end
 		end,
-		nopause=true,
-		priority=priority,
 	}
 end
 
---===== update functions =====--
 
-update = {
-	filter=ecs.Filter.AND{"update"},
-	update=function(self, entity, dt)
-		entity.update(entity, dt)
-	end,
-	priority=50,
-}
+
+--===== update functions =====--
 
 
 
-- 
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