Это лучшее, что я придумал, и оно отлично изменяет размеры, хотя перекрытие заднего буфера вызывает некоторое мерцание краев, еще не тестировалось с DX или OGL, но оно должно работать еще лучше с аппаратным ускорением. Это немного громоздко, но подойдет в качестве доказательства концепции.
Если бы холст можно было обрезать без использования MDI, это было бы еще лучше, например, с использованием буфера битовой маски.
Одна вещь, которой я не доволен, - это координаты положения дочернего окна, потому что они могут работать не во всех системах, но комбинация вызовов GetSystemMetrics для получения размеров границ и заголовков должна исправить это.
/* Smooth resizing of GDI+ MDI window
*
* Click window to resize, hit Escape or Alt+F4 to quit
*
* Character type is set to multibyte
* Project->Properties->Config Properties->General->Character Set = Multibyte
*
* Pritam 2014 */
// Includes
#include <Windows.h>
#include <gdiplus.h>
#pragma comment (lib,"Gdiplus.lib")
using namespace Gdiplus;
// Max resolution
#define XRES 1600
#define YRES 900
// Globals
bool resizing = false;
HWND parent, child; // child is the canvas window, parent provides clipping of child
Bitmap * buffer;
// Render
void Render() {
// Get parent client size
RECT rc;
GetClientRect(parent, &rc);
// Draw backbuffer
Graphics * g = Graphics::FromImage(buffer);
// Clear buffer
g->Clear(Color(100, 100, 100));
// Gray border
Pen pen(Color(255, 180, 180, 180));
g->DrawRectangle(&pen, 10, 10, rc.right - 20, rc.bottom - 20);
pen.SetColor(Color(255, 0, 0, 0));
g->DrawRectangle(&pen, 0, 0, rc.right - 1, rc.bottom - 1);
// Draw buffer to screen
PAINTSTRUCT ps;
HDC hdc = BeginPaint(child, &ps);
Graphics graphics(hdc);
graphics.DrawImage(buffer, Point(0, 0));
// Free
EndPaint(child, &ps);
}
// MDI Callback
LRESULT CALLBACK MDICallback(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
switch(message) {
case WM_LBUTTONDOWN:
resizing = true; // Start resizing
return 0;
break;
case WM_KEYDOWN:
if(wparam == VK_ESCAPE) { // Exit on escape
PostQuitMessage(0);
}
TranslateMessage((const MSG *)&message);
return 0;
break;
case WM_PAINT:
Render();
return 0;
break;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
break;
}
return DefMDIChildProc(hwnd, message, wparam, lparam);
}
// Parent window callback
LRESULT CALLBACK WndCallback(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
return DefFrameProc(hwnd, child, message, wparam, lparam);
}
// Create windows
bool CreateWindows(void) {
// Parent class
WNDCLASSEX wndclass;
ZeroMemory(&wndclass, sizeof(wndclass)); wndclass.cbSize = sizeof(wndclass);
wndclass.style = CS_NOCLOSE;
wndclass.lpfnWndProc = WndCallback;
wndclass.hInstance = GetModuleHandle(NULL);
wndclass.lpszClassName = "WNDCALLBACKPARENT";
wndclass.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
if(!RegisterClassEx(&wndclass)) return false;
// MDI class
wndclass.style = CS_OWNDC | CS_VREDRAW | CS_HREDRAW;
wndclass.lpfnWndProc = MDICallback;
wndclass.lpszClassName = "MDICALLBACKCANVAS";
if(!RegisterClassEx(&wndclass)) return false;
// Parent window styles
DWORD style = WS_POPUP | WS_CLIPCHILDREN;
DWORD exstyle = 0;
// Set initial window size and position
RECT rc;
rc.right = 640;
rc.bottom = 480;
AdjustWindowRectEx(&rc, style, false, exstyle);
rc.left = 20;
rc.top = 20;
// Create window
if(!(parent = CreateWindowEx(exstyle, "MDICLIENT", "MDI Resize", style, rc.left, rc.top, rc.right, rc.bottom, NULL, NULL, wndclass.hInstance, NULL))) return false;
// MDI window styles
style = MDIS_ALLCHILDSTYLES;
exstyle = WS_EX_MDICHILD;
// Set MDI size
rc.left = - 8; // The sizes occupied by borders and caption, if position is not correctly set an ugly caption will appear
rc.top = - 30;
rc.right = XRES;
rc.bottom = YRES;
AdjustWindowRectEx(&rc, style, false, exstyle);
// Create MDI child window
if(!(child = CreateWindowEx(exstyle, "MDICALLBACKCANVAS", "", style, rc.left, rc.top, rc.right, rc.bottom, parent, NULL, wndclass.hInstance, NULL))) return 8;
// Finalize
ShowWindow(child, SW_SHOW);
ShowWindow(parent, SW_SHOWNORMAL);
// Success
return true;
}
// Resize
void Resize(void) {
// Init
RECT rc, rcmdi;
GetClientRect(child, &rcmdi); // Use mdi window size to set max resize for parent
GetWindowRect(parent, &rc);
// Get mouse position
POINT mp;
GetCursorPos(&mp);
// Set new size
rc.right = mp.x - rc.left + 10;
rc.bottom = mp.y - rc.top + 10;
// Apply min & max size
if(rc.right < 240) rc.right = 240; if(rc.bottom < 180) rc.bottom = 180;
if(rc.right > rcmdi.right) rc.right = rcmdi.right; if(rc.bottom > rcmdi.bottom) rc.bottom = rcmdi.bottom;
// Update window size
SetWindowPos(parent, NULL, rc.left, rc.top, rc.right, rc.bottom, SWP_NOZORDER | SWP_NOMOVE);
// Make sure client is entirely repainted
GetClientRect(child, &rc);
InvalidateRect(child, &rc, false);
UpdateWindow(child);
// Stop resizing if mousebutton is up
if(!(GetKeyState(VK_LBUTTON) & 1 << (sizeof(short) * 8 - 1)))
resizing = false;
}
// Main
int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE pinstance, LPSTR cmdline, int cmdshow) {
// Initiate GDI+
ULONG_PTR gdiplusToken;
GdiplusStartupInput gdiplusStartupInput;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
buffer = new Bitmap(XRES, YRES, PixelFormat24bppRGB);
// Create windows
if(!CreateWindows()) return 1;
// Main loop
bool running = true;
MSG message;
while(running) {
// Check message or pass them on to window callback
if(PeekMessage(&message, NULL, 0, 0, PM_REMOVE)) {
if(message.message == WM_QUIT) {
running = false;
} else {
if(!TranslateMDISysAccel(child, &message)) {
TranslateMessage(&message);
DispatchMessage(&message);
}
}
}
// Resize
if(resizing)
Resize();
// Sleep a millisecond to spare the CPU
Sleep(1);
}
// Free memmory and exit
delete buffer;
GdiplusShutdown(gdiplusToken);
return 0;
}
Изменить: еще один пример с использованием «битовой маски»/многослойного окна.
// Escape to quit, left mousebutton to move window, right mousebutton to resize.
// And again char set must be multibyte
// Include
#include <Windows.h>
#include <gdiplus.h>
#pragma comment (lib,"Gdiplus.lib")
using namespace Gdiplus;
// Globals
Bitmap * backbuffer;
int xres, yres;
bool move, size;
POINT framePos, frameSize, mouseOffset;
// Renders the backbuffer
void Render(void) {
if(!backbuffer) return;
// Clear window with mask color
Graphics * gfx = Graphics::FromImage(backbuffer);
gfx->Clear(Color(255, 0, 255));
// Draw stuff
SolidBrush brush(Color(120, 120, 120));
gfx->FillRectangle(&brush, framePos.x, framePos.y, frameSize.x, frameSize.y);
}
// Paints the backbuffer to window
void Paint(HWND hwnd) {
if(!hwnd) return;
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd, &ps);
Graphics gfx(hdc);
gfx.DrawImage(backbuffer, Point(0, 0));
EndPaint(hwnd, &ps);
}
void HandleMove(HWND hwnd) {
// Get mouse position
POINT mouse;
GetCursorPos(&mouse);
// Update frame position
framePos.x = mouse.x - mouseOffset.x;
framePos.y = mouse.y - mouseOffset.y;
// Redraw buffer and invalidate & update window
Render();
InvalidateRect(hwnd, NULL, false);
UpdateWindow(hwnd);
// Stop move
if(!(GetKeyState(VK_LBUTTON) & 1 << (sizeof(short) * 8 - 1)))
move = false;
}
void HandleSize(HWND hwnd) {
// Get mouse position
POINT mouse;
GetCursorPos(&mouse);
// Update frame size
frameSize.x = mouse.x + mouseOffset.x - framePos.x;
frameSize.y = mouse.y + mouseOffset.y - framePos.y;
//frameSize.x = mouse.x + mouseOffset.x;
//frameSize.y = mouse.y + mouseOffset.y;
// Redraw buffer and invalidate & update window
Render();
InvalidateRect(hwnd, NULL, false);
UpdateWindow(hwnd);
// Stop size
if(!(GetKeyState(VK_RBUTTON) & 1 << (sizeof(short) * 8 - 1)))
size = false;
}
LRESULT CALLBACK WindowCallback(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
POINTS p;
switch(msg) {
case WM_KEYDOWN:
if(wparam == VK_ESCAPE) PostQuitMessage(0);
return 0;
break;
case WM_LBUTTONDOWN:
p = MAKEPOINTS(lparam); // Get mouse coords
mouseOffset.x = p.x - framePos.x;
mouseOffset.y = p.y - framePos.y;
move = true;
break;
case WM_RBUTTONDOWN:
p = MAKEPOINTS(lparam);
mouseOffset.x = framePos.x + frameSize.x - p.x;
mouseOffset.y = framePos.y + frameSize.y - p.y;
size = true;
break;
case WM_PAINT:
Paint(hwnd);
return 0;
break;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
break;
}
return DefWindowProc(hwnd, msg, wparam, lparam);
}
// Main
int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE pinstance, LPSTR cmdline, int cmdshow) {
// Init resolution, frame
xres = GetSystemMetrics(SM_CXSCREEN);
yres = GetSystemMetrics(SM_CYSCREEN);
move = false; size = false;
framePos.x = 100; framePos.y = 80;
frameSize.x = 320; frameSize.y = 240;
mouseOffset.x = 0; mouseOffset.y = 0;
// Initiate GDI+
ULONG_PTR gdiplusToken;
GdiplusStartupInput gdiplusStartupInput;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
// Init backbuffer
backbuffer = ::new Bitmap(xres, yres, PixelFormat24bppRGB);
Render();
// Window class
WNDCLASSEX wc; ZeroMemory(&wc, sizeof(wc)); wc.cbSize = sizeof(wc);
wc.style = CS_OWNDC | CS_VREDRAW | CS_HREDRAW;
wc.lpfnWndProc = WindowCallback;
wc.hInstance = GetModuleHandle(NULL);
wc.lpszClassName = "SingleResizeCLASS";
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
if(!RegisterClassEx(&wc)) return 1;
// Create window
HWND hwnd;
DWORD style = WS_POPUP;
DWORD exstyle = WS_EX_LAYERED;
if(!(hwnd = CreateWindowEx(exstyle, wc.lpszClassName, "Resize", style, 0, 0, xres, yres, NULL, NULL, wc.hInstance, NULL)))
return 2;
// Make window fully transparent to avoid the display of unpainted window
SetLayeredWindowAttributes(hwnd, 0, 0, LWA_ALPHA);
// Finalize
ShowWindow(hwnd, SW_SHOWNORMAL);
UpdateWindow(hwnd);
// Make window fully opaque, and set color mask key
SetLayeredWindowAttributes(hwnd, RGB(255, 0, 255), 0, LWA_COLORKEY);
// Main loop
MSG msg;
bool running = true;
while(running) {
// Check message
if(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
if(msg.message == WM_QUIT) {
running = false;
} else {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
// Move or size frame
if(move) { HandleMove(hwnd); }
if(size) { HandleSize(hwnd); }
Sleep(1);
}
// Free memory
::delete backbuffer;
backbuffer = NULL;
GdiplusShutdown(gdiplusToken);
// Exit
return 0;
}
17.04.2014
