render all shapes

1 files changed, 95 insertions, 0 deletions

diff --git a/honey/mesh.lua b/honey/mesh.lua
new file mode 100644
index 0000000..430d5c3
--- /dev/null
+++ b/honey/mesh.lua
@@ -0,0 +1,95 @@
+local mesh = {}
+local gl = honey.gl
+setmetatable(mesh, {__index=_G})
+setfenv(1, mesh)
+
+
+local function insertVertex(vertices, attrib, vertex)
+	local pos = 3*vertex.v_idx
+	for i=1,3 do
+		table.insert(vertices, attrib.vertices[pos+i])
+	end
+
+	local normal = 3*vertex.vn_idx
+	for i=1,3 do
+		table.insert(vertices, attrib.normals[normal+i])
+	end
+
+	local tex = 3*vertex.vt_idx
+	for i=1,2 do
+		table.insert(vertices, attrib.texcoords[tex+i])
+	end
+end
+
+
+function loadShape(shape, attrib)
+	local vertices = {}
+	local indices = {}
+
+	local start = shape.face_offset
+	local finish = start + shape.length
+	for i=start,finish-1 do
+		assert(attrib.face_num_verts[i+1] == 3, "non-triangular face!")
+		for j=0,2 do
+			local vertex = attrib.faces[(3*i) + j + 1]
+			insertVertex(vertices, attrib, vertex)
+			table.insert(indices, #indices)
+		end
+	end
+
+	return vertices, indices
+end
+
+
+function loadFile(filename)
+	local flags = honey.tinyobj.FLAG_TRIANGULATE
+	local attrib, shapes, materials = honey.tinyobj.parse_obj(filename, flags)
+	
+	local meshes = {}
+	for _, shape in ipairs(shapes) do
+		local vertices, indices = loadShape(shape, attrib)
+		table.insert(meshes, Mesh(vertices, indices))
+	end
+	return meshes
+end
+
+
+Mesh = {}
+Mesh.__index = Mesh
+
+
+function Mesh.new(_, vertices, indices)
+	local self = {}
+	setmetatable(self, Mesh)
+
+	self.vertexArray = gl.GenVertexArrays()
+	self.vertexBuffer = gl.GenBuffers()
+	self.elementBuffer = gl.GenBuffers()
+	self.vertexCount = #indices
+
+	gl.BindVertexArray(self.vertexArray)
+	gl.BindBuffer(gl.ARRAY_BUFFER, self.vertexBuffer)
+	gl.BufferData(gl.ARRAY_BUFFER, gl.FLOAT, vertices, gl.STATIC_DRAW)
+
+	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, self.elementBuffer)
+	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, gl.UNSIGNED_INT, indices, gl.STATIC_DRAW)
+
+	gl.VertexAttribPointer(0, 3, false, 8, 0)
+	gl.EnableVertexAttribArray(0)
+	gl.VertexAttribPointer(1, 3, false, 8, 3)
+	gl.EnableVertexAttribArray(1)
+	gl.VertexAttribPointer(2, 2, false, 8, 6)
+	gl.EnableVertexAttribArray(2)
+
+	return self
+end
+setmetatable(Mesh, {__call=Mesh.new})
+
+
+function Mesh.drawElements(self)
+	gl.BindVertexArray(self.vertexArray)
+	gl.DrawElements(gl.TRIANGLES, self.vertexCount, gl.UNSIGNED_INT, 0)
+end
+
+
+return mesh