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 "head.asm" segment .text WndProc: push ebp mov ebp, esp cmp dword [ebp + ARG2], WM_PAINT je .handle_paint cmp dword [ebp + ARG2], WM_CLOSE je .handle_close cmp dword [ebp + ARG2], WM_DESTROY je .handle_destroy jmp .handle_default .handle_paint: push ps push dword [ebp + ARG1] call BeginPaint mov [hDC], eax xor eax, eax mov [y], eax .ylp: xor eax, eax mov [x], eax .xlp: push 0ffh push dword [x] push dword [y] push dword [hDC] call SetPixel inc dword [x] cmp dword [x], 100 jb .xlp inc dword [y] cmp dword [y], 100 jb .ylp push ps push dword [ebp + ARG1] call EndPaint xor eax, eax jmp .finish .handle_close: push dword [ebp + ARG1] call DestroyWindow xor eax, eax jmp .finish .handle_destroy: push 0 call PostQuitMessage xor eax, eax jmp .finish .handle_default: push dword [ebp + ARG4] push dword [ebp + ARG3] push dword [ebp + ARG2] push dword [ebp + ARG1] push dword [pDefWndProc] call CallWindowProc .finish: leave ret 16 WinMain: push ebp mov ebp, esp push 0 push 0 push 0 push 0 push 300 push 300 push 0 push 0 push WS_OVERLAPPEDWINDOW | WS_VISIBLE push szAppName push WC_DIALOG push WS_EX_LEFT call CreateWindowEx mov [hWin], eax push WndProc push GWL_WNDPROC push dword [hWin] call SetWindowLong mov [pDefWndProc], eax .loop: push 0 push 0 push 0 push msg call GetMessage cmp eax, 0 je .exit push msg call DispatchMessage jmp .loop .exit: mov eax, [msg + MSG.wParam] leave ret 16 _start: push 0 call GetModuleHandle mov [hInstance], eax call GetCommandLine mov [pCommand], eax push SW_SHOWNORMAL push dword [pCommand] push 0 push dword [hInstance] call WinMain push eax call ExitProcess
Line 8~9:處理繪畫事件
Line 17~20: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 28~32:透過SetPixel()畫出一個正方形,顏色是紅色
Line 40~42:結束繪製
完成