參考資訊:
https://masm32.com/board/index.php
https://www.nasm.us/xdoc/2.13rc9/html/nasmdoc0.html
屏幕的最小顯示單位是像素,像素由紅色(Red)、綠色(Green)、藍色(Blue)、Alpha等四個顏色組成,因此,在呼叫CreateWindow()時,傳入的解析度,如:300x300,代表該視窗(有效區域)的X軸有300個像素,而Y軸則是有300個像素,這個300x300像素的區域是可以用來繪製任何東西,WM_PAINT是處理視窗重新繪畫的事件,繪畫的相關處理都需要在這個事件完成,比較特別的是,Windows視窗將繪圖的許多東西抽象化,最基本的需求是:一個DC(Device Context)和一個BITMAP,DC可以想像成是一個畫台,而BITMAP則是一片畫布(Buffer),DC有了Buffer就可以畫上任何東西並將其顯示在視窗上
main.asm
%include "c:\\nasmx\\inc\\nasmx.inc" %include "c:\\nasmx\\inc\\win32\\msvcrt.inc" %include "c:\\nasmx\\inc\\win32\\windows.inc" %include "c:\\nasmx\\inc\\win32\\gdi32.inc" %include "c:\\nasmx\\inc\\win32\\user32.inc" %include "c:\\nasmx\\inc\\win32\\kernel32.inc" entry start section .data hWin dd 0 hInstance dd 0 defWndProc dd 0 CommandLine dd 0 szCaption declare(NASMX_TCHAR) NASMX_TEXT("main"),0 NASMX_ISTRUC msg, MSG NASMX_IENDSTRUC NASMX_ISTRUC ps, PAINTSTRUCT NASMX_IENDSTRUC section .text proc WndProc, dword hWnd, uint_t uMsg, dword wParam, dword lParam locals local x, DWORD local y, DWORD local hdc, DWORD endlocals switch dword [argv(.uMsg)] case dword WM_PAINT invoke BeginPaint, [argv(.hWnd)], ps mov [var(.hdc)], eax xor eax, eax mov [var(.y)], eax .ylp: xor eax, eax mov [var(.x)], eax .xlp: invoke SetPixel, [var(.hdc)], [var(.x)], [var(.y)], 0ffh inc dword [var(.x)] cmp dword [var(.x)], 100 jb .xlp inc dword [var(.y)] cmp dword [var(.y)], 100 jb .ylp invoke EndPaint, [argv(.hWnd)], ps break case dword WM_CLOSE invoke DestroyWindow, [argv(.hWnd)] break case dword WM_DESTROY invoke PostQuitMessage, 0 break default invoke CallWindowProc, [defWndProc], [argv(.hWnd)], [argv(.uMsg)], [argv(.wParam)], [argv(.lParam)] endswitch endproc proc WinMain, dword hInst, dword hPrevInst, dword CmdLine, dword CmdShow locals none invoke CreateWindowEx, WS_EX_LEFT, WC_DIALOG, szCaption, \ WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0, 0, 300, 300, NULL, NULL, NULL, NULL mov [hWin], eax invoke SetWindowLong, [hWin], GWL_WNDPROC, WndProc mov [defWndProc], eax do invoke DispatchMessage, msg invoke GetMessage, msg, NULL, NULL, NULL while eax, !=, 0 mov eax, dword [msg + MSG.wParam] endproc proc start, dword argc, dword argv locals none invoke GetModuleHandle, NULL mov [hInstance], eax invoke GetCommandLine, NULL mov [CommandLine], eax invoke WinMain, [hInstance], NULL, [CommandLine], SW_SHOWNORMAL invoke ExitProcess, NULL endproc
Line 32~51:處理繪畫事件
Line 33~34:取得視窗的DC,該DC已經有Buffer可以使用,因此,可以直接在上面繪製任何東西
Line 36~48:透過SetPixel()畫出一個正方形,顏色是紅色
Line 50:結束繪製
完成