func main() {
if err := glfw.Init(); err != nil {
log.Fatalln("failed to initialize glfw:", err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 2)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
window, err := glfw.CreateWindow(800, 600, "Cube", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
if err := gl.Init(); err != nil {
panic(err)
}
texture = newTexture("square.png")
defer gl.DeleteTextures(1, &texture)
setupScene()
for !window.ShouldClose() {
drawScene()
window.SwapBuffers()
glfw.PollEvents()
}
}
func render(w *Window) {
for !w.GlWindow.ShouldClose() {
//Reset?
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
if w.DrawFunc != nil {
w.DrawFunc()
}
// Maintenance
w.GlWindow.SwapBuffers()
glfw.PollEvents()
}
}
func (u *userInterface) setScreenSize(width, height int, scale float64) (bool, error) {
if u.width == width && u.height == height && u.scale == scale {
return false, nil
}
origScale := u.scale
u.scale = scale
// On Windows, giving a too small width doesn't call a callback (#165).
// To prevent hanging up, return asap if the width is too small.
// 252 is an arbitrary number and I guess this is small enough.
// TODO: The same check should be in ui_js.go
const minWindowWidth = 252
if int(float64(width)*u.actualScreenScale()) < minWindowWidth {
u.scale = origScale
return false, nil
}
u.width = width
u.height = height
// To make sure the current existing framebuffers are rendered,
// swap buffers here before SetSize is called.
if err := u.swapBuffers(); err != nil {
return false, err
}
ch := make(chan struct{})
window := u.window
window.SetFramebufferSizeCallback(func(_ *glfw.Window, width, height int) {
window.SetFramebufferSizeCallback(nil)
close(ch)
})
w, h := u.glfwSize()
window.SetSize(w, h)
event:
for {
glfw.PollEvents()
select {
case <-ch:
break event
default:
}
}
u.sizeChanged = true
return true, nil
}
func main() {
if err := glfw.Init(); err != nil {
log.Fatalln("failed to initialize glfw:", err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Cube", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// Initialize Glow
if err := gl.Init(); err != nil {
panic(err)
}
version := gl.GoStr(gl.GetString(gl.VERSION))
fmt.Println("OpenGL version", version)
// Configure the vertex and fragment shaders
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
projection := mgl32.Perspective(mgl32.DegToRad(45.0), float32(windowWidth)/windowHeight, 0.1, 10.0)
projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
camera := mgl32.LookAtV(mgl32.Vec3{3, 3, 3}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})
cameraUniform := gl.GetUniformLocation(program, gl.Str("camera\x00"))
gl.UniformMatrix4fv(cameraUniform, 1, false, &camera[0])
model := mgl32.Ident4()
modelUniform := gl.GetUniformLocation(program, gl.Str("model\x00"))
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
textureUniform := gl.GetUniformLocation(program, gl.Str("tex\x00"))
gl.Uniform1i(textureUniform, 0)
gl.BindFragDataLocation(program, 0, gl.Str("outputColor\x00"))
// Load the texture
texture, err := newTexture("square.png")
if err != nil {
log.Fatalln(err)
}
// Configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(cubeVertices)*4, gl.Ptr(cubeVertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
texCoordAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texCoordAttrib)
gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
// Configure global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
angle := 0.0
previousTime := glfw.GetTime()
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
// Update
time := glfw.GetTime()
elapsed := time - previousTime
previousTime = time
angle += elapsed
model = mgl32.HomogRotate3D(float32(angle), mgl32.Vec3{0, 1, 0})
// Render
gl.UseProgram(program)
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindVertexArray(vao)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, texture)
gl.DrawArrays(gl.TRIANGLES, 0, 6*2*3)
// Maintenance
window.SwapBuffers()
glfw.PollEvents()
}
}
func (w *Window) Show() {
if err := glfw.Init(); err != nil {
log.Fatalln("failed to initialize glfw:", err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.Resizable, glfw.True)
window, err := glfw.CreateWindow(w.W, w.H, w.Title, nil, nil)
if err != nil {
panic(err)
}
if err := gl.Init(); err != nil {
panic(err)
}
window.MakeContextCurrent()
if len(w.Icon) == 1 {
window.SetIcon(w.Icon)
}
if w.RestrictionsEnabled {
window.SetSizeLimits(w.MinW, w.MinH, w.MaxW, w.MaxH)
}
if w.Blend {
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
} else if w.Smooth {
gl.Enable(gl.SMOOTH)
gl.Enable(gl.POINT_SMOOTH)
gl.Enable(gl.LINE_SMOOTH)
gl.Enable(gl.POLYGON_SMOOTH)
gl.Enable(gl.RELATIVE_SMOOTH_CUBIC_CURVE_TO_NV)
gl.Enable(gl.RELATIVE_SMOOTH_QUADRATIC_CURVE_TO_NV)
} else if w.Multisample {
gl.Enable(gl.MULTISAMPLE)
}
reshape(w.W, w.H)
window.SetRefreshCallback(func(g *glfw.Window) { reshape(w.W, w.H) })
window.SetSizeCallback(func(g *glfw.Window, width int, height int) {
reshape(width, height)
w.W = width
w.H = height
})
version := gl.GoStr(gl.GetString(gl.VERSION))
if !silentMode {
fmt.Println("OpenGL version", version)
}
for !window.ShouldClose() {
//Reset?
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
if w.DrawFunc != nil {
w.DrawFunc()
}
// Maintenance
gl.Flush()
window.SwapBuffers()
glfw.PollEvents()
}
}
func (u *userInterface) pollEvents() error {
glfw.PollEvents()
return currentInput.update(u.window, u.scale*glfwScale())
}
