Direct2D 第1篇 最简单的D2D程序

原文:Direct2D 第1篇 最简单的D2D程序

编译之前，得先安装DirectX SDK

#include <windows.h>
#include <d2d1.h>
#include <d2d1helper.h>
#include <dwrite.h>
#pragma comment(lib, "dwrite.lib")
#pragma comment(lib, "d2d1.lib")  

static HINSTANCE g_hinst;
static HWND g_hwnd;
static bool g_flag_app_exit;

static ID2D1Factory * g_factory;
static ID2D1HwndRenderTarget * g_render_target;  

void OnSize(LPARAM lparam)
{
    if(g_render_target)
        g_render_target->Resize(D2D1::SizeU(LOWORD(lparam),HIWORD(lparam)));
}  

bool AppInit()
{
    D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &g_factory);  

    RECT rc;
    GetClientRect(g_hwnd, &rc);  

    g_factory->CreateHwndRenderTarget(
        D2D1::RenderTargetProperties(),
        D2D1::HwndRenderTargetProperties(g_hwnd, D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top)    ),
        &g_render_target);  

    return true;
}  

void OnPaint()
{
    if(!g_render_target)
        return;  

    g_render_target->BeginDraw();
    g_render_target->Clear(D2D1::ColorF(0.63, 0.84, 0.00));
    g_render_target->EndDraw();
}  

void AppExit()
{
    g_render_target->Release();
    g_factory->Release();
}  

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    switch(msg)
    {
    case WM_PAINT:
        OnPaint();
        break;  

    case WM_SIZE:
        OnSize(lparam);
        break;  

	case WM_DESTROY:
        g_flag_app_exit = true;
        break;  

    default:
        return DefWindowProc(hwnd, msg, wparam, lparam);
    }
    return 0;
}  

int WINAPI WinMain(HINSTANCE hinst, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    MSG msg;    

    memset(&wc,0,sizeof(wc));
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.lpfnWndProc = WndProc;
    wc.hInstance = hinst;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszClassName = "WindowClass";
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);   

    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
        return 0;
    }  

    g_hinst = hinst;  

    g_hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,"WindowClass","Direct2D Demo",WS_VISIBLE|WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        640,
        480,
        NULL, NULL, hinst, NULL);  

    if(g_hwnd == NULL)
    {
        MessageBox(NULL, "Window Creation Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
        return 0;
    }  

    if(!AppInit())
    {
        MessageBox(NULL, "Application Initialisation Failed !","Error",MB_ICONEXCLAMATION|MB_OK);
        return 0;
    }  

    while(!g_flag_app_exit)
    {
		if(PeekMessage(&msg, g_hwnd, 0, 0, PM_REMOVE))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
    }  

	AppExit();

    return msg.wParam;
}