1 files changed, 98 insertions, 0 deletions
diff --git a/honey/ecs/render.lua b/honey/ecs/render.lua
new file mode 100644
index 0000000..4217422
--- /dev/null
+++ b/honey/ecs/render.lua
@@ -0,0 +1,98 @@
+local glm = require 'honey.glm'
+local Vec3       = glm.Vec3
+local Mat4       = glm.Mat4
+
+local gl = honey.gl
+local glfw = honey.glfw
+
+local module = {}
+setmetatable(module, {__index=_G})
+setfenv(1, module)
+
+--===== rendering =====--
+
+function draw(model, view, projection, textures, shader, mesh)
+	shader:use()
+
+	-- bind textures
+	local texOffset = 0
+	for name, texTbl in pairs(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
+	shader:configure{
+		float={
+			time=glfw.GetTime(),
+		},
+		matrix={
+			view=view,
+			projection=projection,
+			model=model,
+		},
+	}
+
+	-- draw mesh
+	mesh:drawElements()
+
+	-- unbind textures
+	for i=0,texOffset-1 do
+		gl.BindTexture(gl.TEXTURE_2D + i, 0)
+	end
+end
+
+system = function(params) 
+	return {
+		db = params.db,
+		priority = params.priority or 99,
+		update = function(self, dt)
+			for id, camera in pairs(self.db:queryComponent("camera")) do
+				local projection = camera.projection
+				local cameraTransform = self.db:getComponent(id, "node")
+				local view = Mat4()
+				if cameraTransform then
+					honey.glm.mat4_inv(cameraTransform._matrix.data, view.data)
+				else
+					view:identity()
+				end
+		
+				local entities = self.db:queryComponent("renderMesh")
+				for entity, tbl in pairs(entities) do
+					-- get model
+					local node = self.db:getComponent(entity, "node")
+					local model = 
+						(node and node._matrix) or 
+						Mat4():identity()
+					-- get shader
+					local shader = honey.shader.loadShader(
+						tbl.shader.vertex, tbl.shader.fragment
+					)
+					-- get mesh
+					local mesh = honey.mesh.loadCached(
+						tbl.mesh.filename, tbl.mesh.index
+					)
+					draw(model, view, projection, tbl.textures, shader, mesh)
+				end
+
+				entities = self.db:queryComponent("renderQuad")
+				local quadmesh = honey.mesh.loadCached("builtin.quad", 1)
+				for entity, tbl in pairs(entities) do
+					-- get model
+					local model = Mat4():identity()
+					-- get shader
+					local shader = honey.shader.loadShader(
+						tbl.shader.vertex, tbl.shader.fragment
+					)
+					draw(model, view, projection, tbl.textures, shader, quadmesh)
+				end
+			end
+		end,
+	}
+end
+
+
+
+return module