highgui.go

package gocv

/*
#include <stdlib.h>
#include "highgui_gocv.h"

void go_onmouse_dispatcher(int event, int x, int y, int flags, void *userdata);
*/
import "C"
import (
	"image"
	"runtime"
	"unsafe"
)

type MouseHandlerFunc func(event int, x int, y int, flags int, userdata interface{})

type mouseHandlerInfo struct {
	c_name_ptr *C.char
	fn         MouseHandlerFunc
	userdata   interface{}
}

var (
	onMouseHandlers = map[string]mouseHandlerInfo{}
)

// Window is a wrapper around OpenCV's "HighGUI" named windows.
// While OpenCV was designed for use in full-scale applications and can be used
// within functionally rich UI frameworks (such as Qt*, WinForms*, or Cocoa*)
// or without any UI at all, sometimes there it is required to try functionality
// quickly and visualize the results. This is what the HighGUI module has been designed for.
//
// For further details, please see:
// http://docs.opencv.org/master/d7/dfc/group__highgui.html
type Window struct {
	name string
	open bool
}

// NewWindow creates a new named OpenCV window
//
// For further details, please see:
// http://docs.opencv.org/master/d7/dfc/group__highgui.html#ga5afdf8410934fd099df85c75b2e0888b
func NewWindow(name string) *Window {
	runtime.LockOSThread()

	cName := C.CString(name)
	defer C.free(unsafe.Pointer(cName))

	C.Window_New(cName, 0)

	return &Window{name: name, open: true}
}

// Close closes and deletes a named OpenCV Window.
//
// For further details, please see:
// http://docs.opencv.org/master/d7/dfc/group__highgui.html#ga851ccdd6961022d1d5b4c4f255dbab34
func (w *Window) Close() error {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	mcbInfo, exists := onMouseHandlers[w.name]
	if exists {
		mcbInfo.fn = nil
		mcbInfo.userdata = nil
		C.free(unsafe.Pointer(mcbInfo.c_name_ptr))
		delete(onMouseHandlers, w.name)
	}

	C.Window_Close(cName)
	w.open = false

	runtime.UnlockOSThread()
	return nil
}

// IsOpen checks to see if the Window seems to be open.
func (w *Window) IsOpen() bool {
	return w.open
}

// WindowFlag value for SetWindowProperty / GetWindowProperty.
type WindowFlag float32

const (
	// WindowNormal indicates a normal window.
	WindowNormal WindowFlag = 0x00000000

	// WindowAutosize indicates a window sized based on the contents.
	WindowAutosize WindowFlag = 0x00000001

	// WindowFullscreen indicates a full-screen window.
	WindowFullscreen WindowFlag = 1

	// WindowFreeRatio indicates allow the user to resize without maintaining aspect ratio.
	WindowFreeRatio WindowFlag = 0x00000100

	// WindowKeepRatio indicates always maintain an aspect ratio that matches the contents.
	WindowKeepRatio WindowFlag = 0x00000000
)

// WindowPropertyFlag flags for SetWindowProperty / GetWindowProperty.
type WindowPropertyFlag int

const (
	// WindowPropertyFullscreen fullscreen property
	// (can be WINDOW_NORMAL or WINDOW_FULLSCREEN).
	WindowPropertyFullscreen WindowPropertyFlag = 0

	// WindowPropertyAutosize is autosize property
	// (can be WINDOW_NORMAL or WINDOW_AUTOSIZE).
	WindowPropertyAutosize WindowPropertyFlag = 1

	// WindowPropertyAspectRatio window's aspect ration
	// (can be set to WINDOW_FREERATIO or WINDOW_KEEPRATIO).
	WindowPropertyAspectRatio WindowPropertyFlag = 2

	// WindowPropertyOpenGL opengl support.
	WindowPropertyOpenGL WindowPropertyFlag = 3

	// WindowPropertyVisible or not.
	WindowPropertyVisible WindowPropertyFlag = 4
)

// GetWindowProperty returns properties of a window.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#gaaf9504b8f9cf19024d9d44a14e461656
func (w *Window) GetWindowProperty(flag WindowPropertyFlag) float64 {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	return float64(C.Window_GetProperty(cName, C.int(flag)))
}

// SetWindowProperty changes parameters of a window dynamically.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga66e4a6db4d4e06148bcdfe0d70a5df27
func (w *Window) SetWindowProperty(flag WindowPropertyFlag, value WindowFlag) {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	C.Window_SetProperty(cName, C.int(flag), C.double(value))
}

// SetWindowTitle updates window title.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga56f8849295fd10d0c319724ddb773d96
func (w *Window) SetWindowTitle(title string) {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	cTitle := C.CString(title)
	defer C.free(unsafe.Pointer(cTitle))

	C.Window_SetTitle(cName, cTitle)
}

// IMShow displays an image Mat in the specified window.
// This function should be followed by the WaitKey function which displays
// the image for specified milliseconds. Otherwise, it won't display the image.
//
// For further details, please see:
// http://docs.opencv.org/master/d7/dfc/group__highgui.html#ga453d42fe4cb60e5723281a89973ee563
func (w *Window) IMShow(img Mat) {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	C.Window_IMShow(cName, img.p)
}

// WaitKey waits for a pressed key.
// This function is the only method in OpenCV's HighGUI that can fetch
// and handle events, so it needs to be called periodically
// for normal event processing
//
// For further details, please see:
// http://docs.opencv.org/master/d7/dfc/group__highgui.html#ga5628525ad33f52eab17feebcfba38bd7
func (w *Window) WaitKey(delay int) int {
	return int(C.Window_WaitKey(C.int(delay)))
}

// WaitKeyEx Similar to waitKey, but returns full key code.
// Note
// Key code is implementation specific and depends on used backend: QT/GTK/Win32/etc
//
// For further details, please see:
// https://docs.opencv.org/4.x/d7/dfc/group__highgui.html#gafa15c0501e0ddd90918f17aa071d3dd0
func (w *Window) WaitKeyEx(delay int) int {
	return int(C.Window_WaitKey(C.int(delay)))
}

// PollKey polls for a pressed key.
// The function pollKey polls for a key event without waiting.
// It returns the code of the pressed key or -1 if no key was pressed since
// the last invocation. To wait until a key was pressed, use waitKey.
//
// The functions waitKey and pollKey are the only methods in HighGUI that can
// fetch and handle GUI events, so one of them needs to be called periodically
// for normal event processing unless HighGUI is used within an environment that
// takes care of event processing.
// The function only works if there is at least one HighGUI window created and
// the window is active. If there are several HighGUI windows, any of them can
// be active.
//
// For further details, please see:
// https://docs.opencv.org/4.x/d7/dfc/group__highgui.html#ga6d20fbd3100ec3badc1eaa653aff99d7
func (w *Window) PollKey() int {
	return int(C.Window_PollKey())
}

// MoveWindow moves window to the specified position.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga8d86b207f7211250dbe6e28f76307ffb
func (w *Window) MoveWindow(x, y int) {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	C.Window_Move(cName, C.int(x), C.int(y))
}

// ResizeWindow resizes window to the specified size.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga9e80e080f7ef33f897e415358aee7f7e
func (w *Window) ResizeWindow(width, height int) {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	C.Window_Resize(cName, C.int(width), C.int(height))
}

// SelectROI selects a Region Of Interest (ROI) on the given image.
// It creates a window and allows user to select a ROI using mouse.
//
// Controls:
// use space or enter to finish selection,
// use key c to cancel selection (function will return a zero Rect).
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga8daf4730d3adf7035b6de9be4c469af5
func (w *Window) SelectROI(img Mat) image.Rectangle {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	r := C.Window_SelectROI(cName, img.p)
	rect := image.Rect(int(r.x), int(r.y), int(r.x+r.width), int(r.y+r.height))
	return rect
}

// SelectROIs selects multiple Regions Of Interest (ROI) on the given image.
// It creates a window and allows user to select ROIs using mouse.
//
// Controls:
// use space or enter to finish current selection and start a new one
// use esc to terminate multiple ROI selection process
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga0f11fad74a6432b8055fb21621a0f893
func (w *Window) SelectROIs(img Mat) []image.Rectangle {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	ret := C.Window_SelectROIs(cName, img.p)
	defer C.Rects_Close(ret)

	return toRectangles(ret)
}

// Deprecated: use Window.SelectROI instead
func SelectROI(name string, img Mat) image.Rectangle {
	cName := C.CString(name)
	defer C.free(unsafe.Pointer(cName))

	r := C.Window_SelectROI(cName, img.p)
	rect := image.Rect(int(r.x), int(r.y), int(r.x+r.width), int(r.y+r.height))
	return rect
}

// Deprecated: use Window.SelectROIs instead
func SelectROIs(name string, img Mat) []image.Rectangle {
	cName := C.CString(name)
	defer C.free(unsafe.Pointer(cName))

	ret := C.Window_SelectROIs(cName, img.p)
	defer C.Rects_Close(ret)

	return toRectangles(ret)
}

// WaitKey that is not attached to a specific Window.
// Only use when no Window exists in your application, e.g. command line app.
func WaitKey(delay int) int {
	return int(C.Window_WaitKey(C.int(delay)))
}

// Trackbar is a wrapper around OpenCV's "HighGUI" window Trackbars.
type Trackbar struct {
	name   string
	parent *Window
}

// CreateTrackbar creates a trackbar and attaches it to the specified window.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#gaf78d2155d30b728fc413803745b67a9b
func (w *Window) CreateTrackbar(name string, max int) *Trackbar {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(name)
	defer C.free(unsafe.Pointer(tName))

	C.Trackbar_Create(cName, tName, C.int(max))
	return &Trackbar{name: name, parent: w}
}

// CreateTrackbarWithValue works like CreateTrackbar but also assigns a
// variable value to be a position synchronized with the trackbar.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#gaf78d2155d30b728fc413803745b67a9b
func (w *Window) CreateTrackbarWithValue(name string, value *int, max int) *Trackbar {
	cName := C.CString(w.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(name)
	defer C.free(unsafe.Pointer(tName))

	C.Trackbar_CreateWithValue(cName, tName, (*C.int)(unsafe.Pointer(value)), C.int(max))
	return &Trackbar{name: name, parent: w}
}

// GetPos returns the trackbar position.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga122632e9e91b9ec06943472c55d9cda8
func (t *Trackbar) GetPos() int {
	cName := C.CString(t.parent.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(t.name)
	defer C.free(unsafe.Pointer(tName))

	return int(C.Trackbar_GetPos(cName, tName))
}

// SetPos sets the trackbar position.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga67d73c4c9430f13481fd58410d01bd8d
func (t *Trackbar) SetPos(pos int) {
	cName := C.CString(t.parent.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(t.name)
	defer C.free(unsafe.Pointer(tName))

	C.Trackbar_SetPos(cName, tName, C.int(pos))
}

// SetMin sets the trackbar minimum position.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#gabe26ffe8d2b60cc678895595a581b7aa
func (t *Trackbar) SetMin(pos int) {
	cName := C.CString(t.parent.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(t.name)
	defer C.free(unsafe.Pointer(tName))

	C.Trackbar_SetMin(cName, tName, C.int(pos))
}

// SetMax sets the trackbar maximum position.
//
// For further details, please see:
// https://docs.opencv.org/master/d7/dfc/group__highgui.html#ga7e5437ccba37f1154b65210902fc4480
func (t *Trackbar) SetMax(pos int) {
	cName := C.CString(t.parent.name)
	defer C.free(unsafe.Pointer(cName))

	tName := C.CString(t.name)
	defer C.free(unsafe.Pointer(tName))

	C.Trackbar_SetMax(cName, tName, C.int(pos))
}

//export go_onmouse_dispatcher
func go_onmouse_dispatcher(event C.int, x C.int, y C.int, flags C.int, userdata unsafe.Pointer) {

	c_winname := (*C.char)(unsafe.Pointer(userdata))
	winName := C.GoString(c_winname)
	info, exists := onMouseHandlers[winName]
	if !exists {
		return
	}
	info.fn(int(event), int(x), int(y), int(flags), info.userdata)
}

func (w *Window) SetMouseHandler(onMOuse MouseHandlerFunc, userdata interface{}) {
	c_winname := C.CString(w.name)

	onMouseHandlers[w.name] = mouseHandlerInfo{
		c_name_ptr: c_winname,
		fn:         onMOuse,
		userdata:   userdata,
	}

	C.Window_SetMouseCallback(c_winname, C.mouse_callback(C.go_onmouse_dispatcher))
}