func OnCursor(window *glfw.Window, xPos float64, yPos float64) {
select {
case CursorInput <- &CursorPosition{float32(xPos), float32(yPos)}:
default:
}
window.SetCursorPos(1024/2, 768/2)
}
// key events are a way to get input from GLFW.
// here we check for the escape key being pressed. if it is pressed,
// request that the window be closed
func keyCallback(w *glfw.Window, key glfw.Key, scancode int, action glfw.Action, mods glfw.ModifierKey) {
if key == glfw.KeyEscape && action == glfw.Press {
w.SetShouldClose(true)
} else if key == glfw.KeyZ && action == glfw.Press {
gZoom = 1
gOffX = 0
gOffY = 0
gBlend = 1
} else if key == glfw.KeyUp && (action == glfw.Press || action == glfw.Repeat) {
gBlend += 0.05
if gBlend > 1 {
gBlend = 1
}
} else if key == glfw.KeyDown && (action == glfw.Press || action == glfw.Repeat) {
gBlend -= 0.05
if gBlend < 0 {
gBlend = 0
}
} else if key == glfw.KeyLeftBracket && (action == glfw.Press || action == glfw.Repeat) {
gZoom /= 2
} else if key == glfw.KeyRightBracket && (action == glfw.Press || action == glfw.Repeat) {
gZoom *= 2
} else if key == glfw.Key1 && (action == glfw.Press || action == glfw.Repeat) {
gBlend = 0
} else if key == glfw.Key2 && (action == glfw.Press || action == glfw.Repeat) {
gBlend = 1
} else if key == glfw.Key3 && (action == glfw.Press || action == glfw.Repeat) {
gBlend = 0.5
} else if key == glfw.KeyH && (action == glfw.Press || action == glfw.Repeat) {
gHelp = !gHelp
}
}
func onCursor(window *glfw.Window, xPos float64, yPos float64) {
select {
case CursorInput <- &CursorPosition{xPos, yPos}:
default:
}
window.SetCursorPos(600, 600)
}
func main() {
var parser = flags.NewParser(&gOpts, flags.Default)
var err error
var args []string
if args, err = parser.Parse(); err != nil {
os.Exit(1)
}
if len(args) < 1 || len(args) > 2 {
panic(fmt.Errorf("Too many or not enough arguments"))
}
gDiffFlag = len(args) == 2
// make sure that we display any errors that are encountered
//glfw.SetErrorCallback(errorCallback)
// the GLFW library has to be initialized before any of the methods
// can be invoked
if err = glfw.Init(); err != nil {
panic(err)
}
// to be tidy, make sure glfw.Terminate() is called at the end of
// the program to clean things up by using `defer`
defer glfw.Terminate()
// hints are the way you configure the features requested for the
// window and are required to be set before calling glfw.CreateWindow().
// desired number of samples to use for mulitsampling
//glfw.WindowHint(glfw.Samples, 4)
// request a OpenGL 4.1 core context
if runtime.GOOS == "darwin" {
glfw.WindowHint(glfw.ContextVersionMajor, 3)
glfw.WindowHint(glfw.ContextVersionMinor, 3)
} else {
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
}
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
// do the actual window creation
var window *glfw.Window
window, err = glfw.CreateWindow(1024, 768, "goicmpgl", nil, nil)
if err != nil {
// we legitimately cannot recover from a failure to create
// the window in this sample, so just bail out
panic(err)
}
// set the callback function to get all of the key input from the user
window.SetKeyCallback(keyCallback)
window.SetMouseButtonCallback(mouseDownCallback)
window.SetScrollCallback(mouseWheelCallback)
window.SetCursorPosCallback(mouseMoveCallback)
// GLFW3 can work with more than one window, so make sure we set our
// new window as the current context to operate on
window.MakeContextCurrent()
// disable v-sync for max FPS if the driver allows it
//glfw.SwapInterval(0)
// make sure that GLEW initializes all of the GL functions
if err = gl.Init(); err != nil {
panic(err)
}
var attribs []string = []string{
"position",
"uvs",
}
// compile our shaders
var progTex0 *Program
if progTex0, err = LoadShaderProgram(vertShader, fragShaderTex0, attribs); err != nil {
panic(err)
}
defer progTex0.DeleteProgram()
var progGrid *Program
if progGrid, err = LoadShaderProgram(vertShader, S_FragmentShader_Grid, attribs); err != nil {
panic(err)
}
defer progGrid.DeleteProgram()
var diffProg2 *Program
if diffProg2, err = LoadShaderProgram(vertShader, sProgram2Src, attribs); err != nil {
panic(err)
}
defer diffProg2.DeleteProgram()
var diffProg3 *Program
if diffProg3, err = LoadShaderProgram(vertShader, sProgram3Src, attribs); err != nil {
panic(err)
}
defer diffProg3.DeleteProgram()
var diffProg4 *Program
if diffProg4, err = LoadShaderProgram(vertShader, sProgram4Src, attribs); err != nil {
panic(err)
}
defer diffProg4.DeleteProgram()
var diffProg5 *Program
if diffProg5, err = LoadShaderProgram(vertShader, sProgram5Src, attribs); err != nil {
panic(err)
}
defer diffProg5.DeleteProgram()
var image1_path string = args[0]
if strings.HasPrefix(image1_path, "http") {
if err, image1_path = downloadImage(image1_path); err != nil {
panic(err)
}
}
var texture *Texture
if err, texture, gImage1 = NewTexture(image1_path, false); err != nil {
panic(err)
}
defer texture.DeleteTexture()
var texture2 *Texture
if gDiffFlag {
var image2_path string = args[1]
if strings.HasPrefix(image2_path, "http") {
if err, image2_path = downloadImage(image2_path); err != nil {
panic(err)
}
}
if err, texture2, gImage2 = NewTexture(image2_path, false); err != nil {
panic(err)
}
defer texture2.DeleteTexture()
if texture.Size.X != texture2.Size.X || texture.Size.Y != texture2.Size.Y {
fmt.Println("WARNING: image dimensions differ!")
} else {
fmt.Printf("image dimensions: %dx%d\n", texture.Size.X, texture.Size.Y)
}
} else {
fmt.Printf("image dimensions: %dx%d\n", texture.Size.X, texture.Size.Y)
}
var font *Font
if err, font = NewFont("Font.png", 16); err != nil {
panic(err)
}
defer font.DeleteFont()
var help1 *String = font.NewString("1: show only A")
defer help1.DeleteString()
var help2 *String = font.NewString("2: show only B")
defer help2.DeleteString()
var help3 *String = font.NewString("3: show diff A&B")
defer help3.DeleteString()
var helph *String = font.NewString("h: toggle this help")
defer helph.DeleteString()
var helparrows *String = font.NewString("<up>,<down>: go from A to B")
defer helparrows.DeleteString()
var helpzoom *String = font.NewString("[]: zoom in/out (also mouse wheel)")
defer helpzoom.DeleteString()
var helpclear *String = font.NewString("Z: reset zoom/view")
defer helpclear.DeleteString()
var helpescape *String = font.NewString("ESC: quit")
defer helpescape.DeleteString()
var vbo *VBO
if vbo, err = NewVBOQuad(0, 0, float32(texture.Size.X), float32(texture.Size.Y)); err != nil {
panic(err)
}
defer vbo.DeleteVBO()
var cnt float32 = 0
// while there's no request to close the window
for !window.ShouldClose() {
cnt += 1
// get the texture of the window because it may have changed since creation
width, height := window.GetFramebufferSize()
wwidth, _ := window.GetSize()
gRetinaScale = float32(width) / float32(wwidth)
//fmt.Printf("x=%d y=%d wx=%d wy=%d\n", width, height, wwidth, wheight)
if cnt >= float32(width) {
cnt = 0
}
var matrix Matrix2x3 = IdentityMatrix2x3()
matrix = matrix.Translate(-1.0, 1.0)
matrix = matrix.Scale(2.0/float32(width), -2.0/float32(height))
// clear it all out
gl.Viewport(0, 0, int32(width), int32(height))
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
gl.BlendEquation(gl.FUNC_ADD)
var matrix3 Matrix2x3 = matrix.Scale(gZoom, gZoom)
matrix3 = matrix3.Translate(gOffX, gOffY)
// draw the grid
if true {
vbo.Bind()
progGrid.UseProgram()
color1 := [4]float32{.4, .4, .4, 1}
color2 := [4]float32{.9, .9, .9, 1}
grid := [3]float32{float32(texture.Size.X), float32(texture.Size.Y), 8 / gZoom}
//fmt.Printf("%.2f %.2f %.2f %.2f\n", grid[0], grid[1], grid[2], grid[3])
progGrid.ProgramUniformMatrix4fv("ModelviewMatrix", matrix3.Array())
progGrid.ProgramUniform4fv("color1", color1)
progGrid.ProgramUniform4fv("color2", color2)
progGrid.ProgramUniform3fv("grid", grid)
if err = progGrid.ValidateProgram(); err != nil {
panic(err)
}
vbo.Draw()
vbo.Unbind()
progGrid.UnuseProgram()
}
// draw the texture
if !gDiffFlag {
vbo.Bind()
progTex0.UseProgram()
texture.BindTexture(0)
progTex0.ProgramUniformMatrix4fv("ModelviewMatrix", matrix3.Array())
progTex0.ProgramUniform1i("tex1", 0)
progTex0.ProgramUniform1f("blend", gBlend)
if err = progTex0.ValidateProgram(); err != nil {
panic(err)
}
vbo.Draw()
vbo.Unbind()
progTex0.UnuseProgram()
texture.UnbindTexture(0)
} else {
var diffBlend float32 = gBlend
var diffProg *Program
if diffBlend < 0.25 {
diffBlend *= 4
diffProg = diffProg2
} else if diffBlend < 0.5 { // 0.25 -> 0.5
diffBlend = 4*diffBlend - 1
diffProg = diffProg4
} else if diffBlend < 0.75 { // 0.5 -> 0.75
diffBlend = 4*diffBlend - 2
diffProg = diffProg5
} else { // 0.75 -> 1.0=
diffBlend = 4*diffBlend - 3
diffProg = diffProg3
}
vbo.Bind()
diffProg.UseProgram()
texture.BindTexture(0)
texture2.BindTexture(1)
diffProg.ProgramUniformMatrix4fv("ModelviewMatrix", matrix3.Array())
diffProg.ProgramUniform1i("decalA", 0)
diffProg.ProgramUniform1i("decalB", 1)
diffProg.ProgramUniform1f("diffBlend", diffBlend)
if err = diffProg.ValidateProgram(); err != nil {
panic(err)
}
vbo.Draw()
vbo.Unbind()
diffProg.UnuseProgram()
texture.UnbindTexture(0)
texture2.UnbindTexture(1)
}
// font
if gHelp {
color := [...]float32{0, 0, 1, 1}
bg := [...]float32{0.5, 0.5, 0.5, 0.5}
var line float32 = 0
if err = helph.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128); err != nil {
panic(err)
}
line += 1
help1.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
help2.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
help3.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
helparrows.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
helpzoom.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
helpclear.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
helpescape.Draw(font, color, bg, matrix, 0.5, 20, 100+line*128)
line += 1
}
// swapping OpenGL buffers and polling events has been decoupled
// in GLFW3, so make sure to invoke both here
window.SwapBuffers()
glfw.PollEvents()
}
}