3 files changed, 342 insertions, 0 deletions
diff --git a/honey/asset/image.lua b/honey/asset/image.lua
new file mode 100644
index 0000000..c5bd145
--- /dev/null
+++ b/honey/asset/image.lua
@@ -0,0 +1,49 @@
+local gl = honey.gl
+
+local module = {}
+setmetatable(module, {__index=_G})
+setfenv(1, module)
+
+
+local cache = {}
+
+-- load an image into a gl texture
+local function loadImage(filename)
+	local data, width, height = honey.image.load(filename, 4)
+	local texture = gl.GenTextures()
+	gl.BindTexture(gl.TEXTURE_2D, texture)
+	gl.TexImage2D(
+		gl.TEXTURE_2D, 0,
+		gl.RGBA, width, height,
+		gl.RGBA, gl.UNSIGNED_BYTE, data
+	)
+	gl.GenerateMipmap(gl.TEXTURE_2D)
+	honey.image.destroy(data)
+	return texture
+end
+
+-- cached get a texture
+get = function(filename)
+	if not cache[filename] then
+		cache[filename] = loadImage(filename)
+	end
+	return cache[filename]
+end
+
+-- remove a texture from the cache
+forget = function(filename)
+	local texture = cache[filename]
+	if texture then
+		gl.DeleteTextures(texture)
+	end
+	cache[filename] = nil
+end
+
+-- remove all textures from the cache
+clearCache = function(filename)
+	for key in pairs(cache) do
+		forget(key)
+	end
+end
+
+return module
diff --git a/honey/asset/mesh.lua b/honey/asset/mesh.lua
new file mode 100644
index 0000000..876c5e4
--- /dev/null
+++ b/honey/asset/mesh.lua
@@ -0,0 +1,150 @@
+local gl = honey.gl
+
+local module = {}
+setmetatable(module, {__index=_G})
+setfenv(1, module)
+
+
+-- append the 8 floats per vertex to the vertices table
+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 = 2*vertex.vt_idx
+	for i=1,2 do
+		table.insert(vertices, attrib.texcoords[tex+i])
+	end
+end
+
+
+-- creates a table of floats representing vertex data
+-- and a table of ints representing face indices within the vertices
+local function loadShape(shape, attrib, debug)
+	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, debug)
+			table.insert(indices, #indices)
+		end
+	end
+
+	return vertices, indices
+end
+
+
+-- public helper function (used in some other places, like trimesh construction)
+-- packages the vertices & indices tables from loadShape into a single array
+loadFile = function(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, debug)
+		table.insert(meshes, {vertices=vertices, indices=indices})
+	end
+	return meshes
+end
+
+
+-- helper function to create a gl vertex array object from (vertices, indices) pair
+local function createMesh(vertices, indices)
+	vao = gl.GenVertexArrays()
+	vbo = gl.GenBuffers()
+	ebo = gl.GenBuffers()
+
+	gl.BindVertexArray(vao)
+	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
+	gl.BufferData(gl.ARRAY_BUFFER, gl.FLOAT, vertices, gl.STATIC_DRAW)
+
+	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebo)
+	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, gl.UNSIGNED_INT, indices, gl.STATIC_DRAW)
+
+	local stride = 8
+	local offset = 0
+	
+	-- position
+	gl.VertexAttribPointer(0, 3, false, stride, offset)
+	gl.EnableVertexAttribArray(0)
+	offset = offset+3
+
+	-- normal
+	gl.VertexAttribPointer(1, 3, false, stride, offset)
+	gl.EnableVertexAttribArray(1)
+	offset = offset+3
+
+	-- texture
+	gl.VertexAttribPointer(2, 2, false, stride, offset)
+	gl.EnableVertexAttribArray(2)
+	offset = offset+2
+
+	return vao, vbo, ebo, #vertices
+end
+
+
+local cache = {}
+
+
+-- get a gl vertex array object + vertex count
+get = function(filename, index)
+	if not cache[filename] then
+		local c = {}
+		local meshes = loadFile(filename)
+		for _, m in ipairs(meshes) do
+			local vao, vbo, ebo, count = createMesh(m.vertices, m.indices)
+			table.insert(c, { vao=vao, vbo=vbo, ebo=ebo, count=count })
+		end
+		cache[filename] = c
+	end
+	local m = cache[filename][index]
+	return m.vao, m.count
+end
+
+
+-- forget a mesh
+forget = function(filename)
+	if not cache[filename] then return end
+	for _, m in ipairs(cache[filename]) do
+		gl.DeleteBuffers(m.vbo)
+		gl.DeleteBuffers(m.ebo)
+		gl.DeleteVertexArrays(m.vao)
+	end
+	cache[filename] = nil
+end
+
+
+-- clear the cache
+clearCache = function()
+	for key in pairs(cache) do
+		forget(key)
+	end
+end
+
+
+--===== builtin meshes =====--
+
+function createBuiltins()
+	cache["builtin.quad"] = {Mesh(
+		{ 0, 0, 0,   0, 1, 0,   0, 0,
+		  1, 0, 0,   0, 1, 0,   1, 0,
+		  0, 1, 0,   0, 1, 0,   0, 1,
+		  1, 1, 0,   0, 1, 0,   1, 1 },
+		{ 0, 1, 3, 0, 3, 2 }
+	)}
+end
+
+
+return module 
diff --git a/honey/asset/shader.lua b/honey/asset/shader.lua
new file mode 100644
index 0000000..0e8c93a
--- /dev/null
+++ b/honey/asset/shader.lua
@@ -0,0 +1,143 @@
+local gl = honey.gl
+
+local module = {}
+setmetatable(module, {__index=_G})
+setfenv(1, module)
+
+-- compile glsl source code
+local function compileShader(source, type)
+	local shader = gl.CreateShader(type)
+	gl.ShaderSource(shader, source)
+	gl.CompileShader(shader)
+	return shader
+end
+
+-- helper function
+local builtin = {}
+local function readFile(filename)
+	-- support built-in shaders
+	if builtin[filename] then return builtin[filename] end
+
+	local f, err = io.open(filename)
+	if not f then error(err) end
+	local str = f:read("*a")
+	f:close()
+	return str
+end
+
+
+-- build a shader program from provided source files
+local function buildProgram(sources)
+	local shaders = {}
+
+	-- load & compile shaders
+	if sources.vertex then
+		local shader = compileShader(readFile(sources.vertex), gl.VERTEX_SHADER)
+		table.insert(shaders, shader)
+	end
+	if sources.vertex then
+		local shader = compileShader(readFile(sources.vertex), gl.VERTEX_SHADER)
+		table.insert(shaders, shader)
+	end
+
+	-- link shaders
+	local program = gl.CreateProgram()
+	for _, shader in ipairs(shaders) do
+		gl.AttachShader(program, shader)
+	end
+	gl.LinkProgram(program)
+
+	-- clean up
+	for _, shader in ipairs(shaders) do
+		gl.DeleteShader(shader)
+	end
+
+	return program
+end
+
+
+-- public uniform setters
+function setInt(program, name, value)
+	local location = gl.GetUniformLocation(program, name)
+	gl.Uniform1i(location, value)
+end
+function setFloat(program, name, value)
+	local location = gl.GetUniformLocation(program, name)
+	gl.Uniform1f(location, value)
+end
+function setVec3(program, name, value)
+	local location = gl.GetUniformLocation(program, name)
+	gl.Uniform3f(location, value[1], value[2], value[3])
+end
+function setVec4(program, name, value)
+	local location = gl.GetUniformLocation(program, name)
+	gl.Uniform3f(location, value[1], value[2], value[3], value[4])
+end
+function setMatrix(program, name, matrix)
+	local location = gl.GetUniformLocation(program, name)
+	gl.UniformMatrix4fv(location, false, matrix.data)
+end
+
+
+function configure(program, tbl)
+	local processKey = function(key, set)
+		local subtbl = tbl[key]
+		if subtbl then
+			for name, value in pairs(subtbl) do 
+				set(program, name, value)
+			end
+		end
+	end
+
+	processKey("int", setInt)
+	processKey("float", setFloat)
+	processKey("vec3", setVec3)
+	processKey("vec4", setVec4)
+	processKey("matrix", setMatrix)
+end
+
+
+--===== public asset cache functions =====--
+
+local cache = {}
+
+
+-- generate id string based on shader sources
+local function shaderId(sources)
+	return string.format(
+		"%s;%s", 
+		sources.vertex or "nil", 
+		sources.fragment or "nil"
+	)
+end
+
+-- get a cached shader program
+get = function(sources)
+	local id = shaderId(sources)
+	if not cache[id] then
+		cache[id] = buildProgram(sources)
+	end
+	return cache[id]
+end
+
+
+-- remove a cached shader program
+forget = function(sources)
+	local id = shaderId(sources)
+	if cache[id] then
+		gl.DeleteProgram(cache[id])
+		cache[id] = nil
+	end
+end
+
+
+-- clear the cache
+clearCache = function()
+	for key, program in pairs(cache) do
+		gl.DeleteProgram(program)
+		cache[key] = nil
+	end
+end
+
+
+return module