// Renderer implementation.
// BindTexture makes the texture available on the GPU.
func (gc *opengl) BindTexture(tid *uint32, img image.Image, repeat bool) (err error) {
if glerr := gl.GetError(); glerr != gl.NO_ERROR {
log.Printf("opengl:bindTexture need to find and fix prior error %X", glerr)
}
if *tid == 0 {
gl.GenTextures(1, tid)
}
gl.BindTexture(gl.TEXTURE_2D, *tid)
// FUTURE: check if RGBA, or NRGBA are alpha pre-multiplied. The docs say yes
// for RGBA but the data is from PNG files which are not pre-multiplied
// and the go png Decode looks like its reading values directly.
var ptr gl.Pointer
bounds := img.Bounds()
width, height := int32(bounds.Dx()), int32(bounds.Dy())
switch imgType := img.(type) {
case *image.RGBA:
i := img.(*image.RGBA)
ptr = gl.Pointer(&(i.Pix[0]))
case *image.NRGBA:
i := img.(*image.NRGBA)
ptr = gl.Pointer(&(i.Pix[0]))
default:
return fmt.Errorf("Unsupported image format %T", imgType)
}
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, ptr)
gl.GenerateMipmap(gl.TEXTURE_2D)
gc.setTextureMode(*tid, repeat)
if glerr := gl.GetError(); glerr != gl.NO_ERROR {
err = fmt.Errorf("Failed binding texture %d\n", glerr)
}
return err
}
// BindFrame creates a framebuffer object with an associated texture.
// http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-14-render-to-texture/
// http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-16-shadow-mapping/
func (gc *opengl) BindFrame(buf int, fbo, tid, db *uint32) (err error) {
size := int32(1024)
gl.GenFramebuffers(1, fbo)
gl.BindFramebuffer(gl.FRAMEBUFFER, *fbo)
// Create a texture specifically for the framebuffer.
gl.GenTextures(1, tid)
gl.BindTexture(gl.TEXTURE_2D, *tid)
switch buf {
case IMAGE_BUFF:
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, size, size,
0, gl.RGBA, gl.UNSIGNED_BYTE, gl.Pointer(nil))
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
// Add a depth buffer to mimic the normal framebuffer behaviour for 3D objects.
gl.GenRenderbuffers(1, db)
gl.BindRenderbuffer(gl.RENDERBUFFER, *db)
gl.RenderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT, size, size)
gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, *db)
// Associate the texture with the framebuffer.
gl.FramebufferTexture(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, *tid, 0)
buffType := uint32(gl.COLOR_ATTACHMENT0)
gl.DrawBuffers(1, &buffType)
case DEPTH_BUFF:
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.DEPTH_COMPONENT16, size, size,
0, gl.DEPTH_COMPONENT, gl.FLOAT, gl.Pointer(nil))
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_COMPARE_FUNC, gl.LEQUAL)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_COMPARE_MODE, gl.COMPARE_REF_TO_TEXTURE)
// Associate the texture with the framebuffer.
gl.FramebufferTexture(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, *tid, 0)
gl.DrawBuffer(gl.NONE)
default:
return fmt.Errorf("BindFrame unrecognized buffer type.")
}
// Report any problems.
glerr := gl.CheckFramebufferStatus(gl.FRAMEBUFFER)
if glerr != gl.FRAMEBUFFER_COMPLETE {
return fmt.Errorf("BindFrame error %X", glerr)
}
if glerr := gl.GetError(); glerr != gl.NO_ERROR {
err = fmt.Errorf("Failed binding framebuffer %X", glerr)
}
gl.BindFramebuffer(gl.FRAMEBUFFER, 0) // clean up by resetting to default framebuffer.
return err
}
// initScene is one time initialization that creates a single VAO
func (tag *trtag) initScene() {
tag.mvp64 = lin.NewM4()
tag.persp = lin.NewM4().Persp(60, float64(600)/float64(600), 0.1, 50)
tag.mvp = render.NewMvp()
tag.initData()
// Bind the OpenGL calls and dump some version info.
gl.Init()
fmt.Printf("%s %s", gl.GetString(gl.RENDERER), gl.GetString(gl.VERSION))
fmt.Printf(" GLSL %s\n", gl.GetString(gl.SHADING_LANGUAGE_VERSION))
// Gather the one scene into this one vertex array object.
gl.GenVertexArrays(1, &tag.vao)
gl.BindVertexArray(tag.vao)
// create shaders
tag.initShader()
gl.UseProgram(tag.shaders)
// vertex data.
var vbuff uint32
gl.GenBuffers(1, &vbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, vbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(tag.verticies)*4), gl.Pointer(&(tag.verticies[0])), gl.STATIC_DRAW)
vattr := uint32(gl.GetAttribLocation(tag.shaders, "in_v"))
gl.EnableVertexAttribArray(vattr)
gl.VertexAttribPointer(vattr, 3, gl.FLOAT, false, 0, 0)
// colour data.
var cbuff uint32
gl.GenBuffers(1, &cbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, cbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(tag.colour)*4), gl.Pointer(&(tag.colour[0])), gl.STATIC_DRAW)
cattr := uint32(gl.GetAttribLocation(tag.shaders, "in_c"))
gl.EnableVertexAttribArray(cattr)
gl.VertexAttribPointer(cattr, 4, gl.FLOAT, false, 0, 0)
// faces data.
var ebuff uint32
gl.GenBuffers(1, &ebuff)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebuff)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int64(len(tag.faces)), gl.Pointer(&(tag.faces[0])), gl.STATIC_DRAW)
// set some state that doesn't need to change during drawing.
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
gl.Enable(gl.CULL_FACE)
gl.CullFace(gl.BACK)
}
// initScene is one time initialization that creates a single VAO
func (sf *sftag) initScene() {
sf.sTime = time.Now()
sf.initData()
// Bind the OpenGL calls and dump some version info.
gl.Init()
fmt.Printf("%s %s", gl.GetString(gl.RENDERER), gl.GetString(gl.VERSION))
fmt.Printf(" GLSL %s\n", gl.GetString(gl.SHADING_LANGUAGE_VERSION))
gl.GenVertexArrays(1, &sf.vao)
gl.BindVertexArray(sf.vao)
// vertex data.
var vbuff uint32
gl.GenBuffers(1, &vbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, vbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(sf.verticies)*4), gl.Pointer(&(sf.verticies[0])), gl.STATIC_DRAW)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0)
gl.EnableVertexAttribArray(0)
// faces data.
var ebuff uint32
gl.GenBuffers(1, &ebuff)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebuff)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int64(len(sf.faces)), gl.Pointer(&(sf.faces[0])), gl.STATIC_DRAW)
// create texture and shaders after all the data has been set up.
// renderer := render.New()
shader := "fire"
loader := load.NewLoader()
vsrc, verr := loader.Vsh(shader)
fsrc, ferr := loader.Fsh(shader)
if verr == nil && ferr == nil {
sf.shaders = gl.CreateProgram()
if err := gl.BindProgram(sf.shaders, vsrc, fsrc); err != nil {
fmt.Printf("Failed to create program: %s\n", err)
}
sf.mvpref = gl.GetUniformLocation(sf.shaders, "mvpm")
sf.gTime = gl.GetUniformLocation(sf.shaders, "time")
sf.sizes = gl.GetUniformLocation(sf.shaders, "screen")
sf.mvp = render.NewMvp().Set(lin.NewM4().Ortho(0, 4, 0, 4, 0, 10))
// set some state that doesn't need to change during drawing.
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
}
}
// initScene is called once on startup to load the 3D data.
func (ld *ldtag) initScene() {
ld.persp = lin.NewM4()
ld.mvp64 = lin.NewM4()
ld.mvp = render.NewMvp()
gl.Init()
ldr := load.NewLoader()
meshes, _ := ldr.Obj("monkey")
mesh := meshes[0]
ld.faceCount = int32(len(mesh.F))
// Gather the one scene into this one vertex array object.
gl.GenVertexArrays(1, &ld.vao)
gl.BindVertexArray(ld.vao)
// vertex data.
var vbuff uint32
gl.GenBuffers(1, &vbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, vbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(mesh.V)*4), gl.Pointer(&(mesh.V[0])), gl.STATIC_DRAW)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0)
gl.EnableVertexAttribArray(0)
// normal data.
var nbuff uint32
gl.GenBuffers(1, &nbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, nbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(mesh.N)*4), gl.Pointer(&(mesh.N[0])), gl.STATIC_DRAW)
gl.VertexAttribPointer(1, 3, gl.FLOAT, false, 0, 0)
gl.EnableVertexAttribArray(1)
// faces data, uint32 in this case, so 4 bytes per element.
var fbuff uint32
gl.GenBuffers(1, &fbuff)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, fbuff)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int64(len(mesh.F)*2), gl.Pointer(&(mesh.F[0])), gl.STATIC_DRAW)
ld.initShader()
gl.ClearColor(0.2, 0.2, 0.2, 1.0)
gl.Enable(gl.DEPTH_TEST)
gl.Enable(gl.CULL_FACE)
// set the initial perspetive matrix.
ld.resize(0, 0, 800, 600)
}
// bindFaceBuffer copies triangle face data from the CPU to the GPU.
func (gc *opengl) bindFaceBuffer(fdata Data) {
fd := fdata.(*faceData)
if len(fd.data) > 0 {
if fd.ref == 0 {
gl.GenBuffers(1, &fd.ref)
}
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, fd.ref)
bytes := 2 // 2 bytes for uint16 (gl.UNSIGNED_SHORT)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int64(len(fd.data)*bytes), gl.Pointer(&(fd.data[0])), fd.usage)
}
}
// bindVertexBuffer copies per-vertex data from the CPU to the GPU.
func (gc *opengl) bindVertexBuffer(vdata Data) {
vd, ok := vdata.(*vertexData)
if !ok {
return
}
if vd.ref == 0 {
gl.GenBuffers(1, &vd.ref)
}
bytes := 4 // 4 bytes for float32 (gl.FLOAT)
switch vd.usage {
case STATIC:
switch {
case len(vd.floats) > 0:
gl.BindBuffer(gl.ARRAY_BUFFER, vd.ref)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(vd.floats)*bytes), gl.Pointer(&(vd.floats[0])), vd.usage)
gl.VertexAttribPointer(vd.lloc, vd.span, gl.FLOAT, false, 0, 0)
case len(vd.bytes) > 0:
gl.BindBuffer(gl.ARRAY_BUFFER, vd.ref)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(vd.bytes)), gl.Pointer(&(vd.bytes[0])), vd.usage)
gl.VertexAttribPointer(vd.lloc, vd.span, gl.UNSIGNED_BYTE, vd.normalize, 0, 0)
}
case DYNAMIC:
var null gl.Pointer // zero.
switch {
case len(vd.floats) > 0:
gl.BindBuffer(gl.ARRAY_BUFFER, vd.ref)
// Buffer orphaning, a common way to improve streaming perf. See:
// http://www.opengl.org/wiki/Buffer_Object_Streaming
gl.BufferData(gl.ARRAY_BUFFER, int64(cap(vd.floats)*bytes), null, vd.usage)
gl.BufferSubData(gl.ARRAY_BUFFER, 0, int64(len(vd.floats)*bytes), gl.Pointer(&(vd.floats[0])))
gl.VertexAttribPointer(vd.lloc, vd.span, gl.FLOAT, false, 0, 0)
}
}
gl.EnableVertexAttribArray(vd.lloc)
}
// initRender is one time initialization that creates a single VAO
// to display a single ray trace generated texture.
func (rt *rtrace) initRender() {
rt.verts = []float32{ // four verticies for a quad.
0, 0, 0,
4, 0, 0,
0, 4, 0,
4, 4, 0,
}
rt.faces = []uint8{ // create quad from 2 triangles.
0, 2, 1,
1, 2, 3,
}
rt.uvs = []float32{ // texture coordinates to sample the image.
0, 0,
1, 0,
0, 1,
1, 1,
}
// Start up OpenGL and create a single vertex array object.
gl.Init()
gl.GenVertexArrays(1, &rt.vao)
gl.BindVertexArray(rt.vao)
// vertex data.
var vbuff uint32
gl.GenBuffers(1, &vbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, vbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(rt.verts)*4), gl.Pointer(&(rt.verts[0])), gl.STATIC_DRAW)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0)
gl.EnableVertexAttribArray(0)
// faces data.
var ebuff uint32
gl.GenBuffers(1, &ebuff)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebuff)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int64(len(rt.faces)), gl.Pointer(&(rt.faces[0])), gl.STATIC_DRAW)
// texture coordatinates
var tbuff uint32
gl.GenBuffers(1, &tbuff)
gl.BindBuffer(gl.ARRAY_BUFFER, tbuff)
gl.BufferData(gl.ARRAY_BUFFER, int64(len(rt.uvs)*4), gl.Pointer(&(rt.uvs[0])), gl.STATIC_DRAW)
var tattr uint32 = 2
gl.VertexAttribPointer(tattr, 2, gl.FLOAT, false, 0, 0)
gl.EnableVertexAttribArray(tattr)
// use ray trace generated texture image.
bounds := rt.img.Bounds()
width, height := int32(bounds.Dx()), int32(bounds.Dy())
ptr := gl.Pointer(&(rt.img.Pix[0]))
gl.GenTextures(1, &rt.texId)
gl.BindTexture(gl.TEXTURE_2D, rt.texId)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, ptr)
// texture sampling shader.
loader := load.NewLoader()
shader := "tuv"
vsrc, verr := loader.Vsh(shader)
fsrc, ferr := loader.Fsh(shader)
if verr != nil || ferr != nil {
log.Fatalf("Failed to load shaders %s %s\n", verr, ferr)
}
rt.shaders = gl.CreateProgram()
if err := gl.BindProgram(rt.shaders, vsrc, fsrc); err != nil {
log.Fatalf("Failed to create program: %s\n", err)
}
rt.mvpId = gl.GetUniformLocation(rt.shaders, "mvpm")
rt.tex2D = gl.GetUniformLocation(rt.shaders, "sampler2D")
rt.mvp = render.NewMvp().Set(lin.NewM4().Ortho(0, 4, 0, 4, 0, 10))
// set some state that doesn't need to change during drawing.
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
}