图形编程

Windows GDI, GDI++, OpenGl, DirectX

Direct2D 画图

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

#include "basewin.h"

template <class T> void SafeRelease(T **ppT)
{
if (*ppT)
{
(*ppT)->Release();
*ppT = NULL;
}
}

class MainWindow : public BaseWindow<MainWindow>
{
ID2D1Factory            *pFactory;
ID2D1HwndRenderTarget   *pRenderTarget;
ID2D1SolidColorBrush    *pBrush;
D2D1_ELLIPSE            ellipse;

void    CalculateLayout();
HRESULT CreateGraphicsResources();
void    DiscardGraphicsResources();
void    OnPaint();
void    Resize();

public:

MainWindow() : pFactory(NULL), pRenderTarget(NULL), pBrush(NULL)
{
}

PCWSTR  ClassName() const { return L"Circle Window Class"; }
LRESULT HandleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam);
};

// Recalculate drawing layout when the size of the window changes.

void MainWindow::CalculateLayout()
{
if (pRenderTarget != NULL)
{
D2D1_SIZE_F size = pRenderTarget->GetSize();
const float x = size.width / 2;
const float y = size.height / 2;
const float radius = min(x, y);
ellipse = D2D1::Ellipse(D2D1::Point2F(x, y), radius, radius);
}
}

HRESULT MainWindow::CreateGraphicsResources()
{
HRESULT hr = S_OK;
if (pRenderTarget == NULL)
{
RECT rc;
GetClientRect(m_hwnd, &rc);

D2D1_SIZE_U size = D2D1::SizeU(rc.right, rc.bottom);

hr = pFactory->CreateHwndRenderTarget(
D2D1::RenderTargetProperties(),
D2D1::HwndRenderTargetProperties(m_hwnd, size),
&pRenderTarget);

if (SUCCEEDED(hr))
{
const D2D1_COLOR_F color = D2D1::ColorF(1.0f, 1.0f, 0);
hr = pRenderTarget->CreateSolidColorBrush(color, &pBrush);

if (SUCCEEDED(hr))
{
CalculateLayout();
}
}
}
return hr;
}

void MainWindow::DiscardGraphicsResources()
{
SafeRelease(&pRenderTarget);
SafeRelease(&pBrush);
}

void MainWindow::OnPaint()
{
HRESULT hr = CreateGraphicsResources();
if (SUCCEEDED(hr))
{
PAINTSTRUCT ps;
BeginPaint(m_hwnd, &ps);

pRenderTarget->BeginDraw();

pRenderTarget->Clear( D2D1::ColorF(D2D1::ColorF::SkyBlue) );
pRenderTarget->FillEllipse(ellipse, pBrush);

hr = pRenderTarget->EndDraw();
if (FAILED(hr) || hr == D2DERR_RECREATE_TARGET)
{
DiscardGraphicsResources();
}
EndPaint(m_hwnd, &ps);
}
}

void MainWindow::Resize()
{
if (pRenderTarget != NULL)
{
RECT rc;
GetClientRect(m_hwnd, &rc);

D2D1_SIZE_U size = D2D1::SizeU(rc.right, rc.bottom);

pRenderTarget->Resize(size);
CalculateLayout();
InvalidateRect(m_hwnd, NULL, FALSE);
}
}

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR, int nCmdShow)
{
MainWindow win;

if (!win.Create(L"Circle", WS_OVERLAPPEDWINDOW))
{
return 0;
}

ShowWindow(win.Window(), nCmdShow);

// Run the message loop.

MSG msg = { };
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}

return 0;
}

LRESULT MainWindow::HandleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
case WM_CREATE:
if (FAILED(D2D1CreateFactory(
D2D1_FACTORY_TYPE_SINGLE_THREADED, &pFactory)))
{
return -1;  // Fail CreateWindowEx.
}
return 0;

case WM_DESTROY:
DiscardGraphicsResources();
SafeRelease(&pFactory);
PostQuitMessage(0);
return 0;

case WM_PAINT:
OnPaint();
return 0;

case WM_SIZE:
Resize();
return 0;
}
return DefWindowProc(m_hwnd, uMsg, wParam, lParam);
}

屏幕截图：http://blog.csdn.net/theforger/article/details/51752230

Windows GDI： https://msdn.microsoft.com/en-us/library/dd145203(v=vs.85).aspx

Legacy Graphics: https://msdn.microsoft.com/en-us/library/hh309470(v=vs.85).aspx

Module 3. Windows Graphics： https://msdn.microsoft.com/en-us/library/ff684175(v=vs.85).aspx

设备上下文: http://blog.csdn.net/theforger/article/details/51095964