MSDN Community

DirectX (Direct3D, Direct2D, DirectWrite)

DirectX is Microsoft's suite of technologies for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. For graphics, the core components are:

• Direct3D: Used for rendering 2D and 3D vector graphics. It's the backbone of modern Windows gaming and high-performance graphics applications.
• Direct2D: A hardware-accelerated, immediate-mode API that provides high performance for 2D graphics and text rendering. Ideal for user interfaces and vector graphics.
• DirectWrite: Provides high-quality text rendering, features like measuring text, and creating full Unicode text layout.

Explore more about DirectX here.

GDI (Graphics Device Interface)

GDI is the older, traditional API for 2D graphics on Windows. While less performant than DirectX for complex scenes, it's still widely used for basic drawing, printing, and simpler UI elements.

• Provides functions for drawing lines, shapes, text, and managing graphical objects like pens, brushes, and fonts.
• It's a retained-mode API, meaning the system maintains the graphical state.

Learn more about GDI here.

GDI+

GDI+ is an enhanced version of GDI, offering improved features for graphics and image manipulation, including:

• Advanced typography, color management, and 2D vector graphics.
• Support for various image formats like JPEG, PNG, GIF, and TIFF.
• Often accessed through managed code (e.g., .NET).

Common Graphics Concepts

Key concepts to understand when working with Windows Graphics APIs include:

• Device Context (DC): A data structure that describes the drawing attributes of output devices like the screen or printer.
• Bitmaps: Raster graphics images composed of pixels.
• Vectors: Graphics defined by mathematical equations, representing lines, curves, and shapes.
• Shaders: Small programs that run on the GPU to determine how vertices are positioned and how surfaces are colored.
• Color Models: RGB, CMYK, etc., and how they are represented.

Example: Basic GDI Drawing (Conceptual)

Here's a conceptual snippet showing how you might draw a rectangle using GDI:

// Get a device context for the window
HDC hdc = GetDC(hWnd);

// Create a pen for the border
HPEN hPen = CreatePen(PS_SOLID, 2, RGB(255, 0, 0)); // Red, 2 pixels wide
HGDIOBJ hOldPen = SelectObject(hdc, hPen);

// Create a brush for the fill
HBRUSH hBrush = CreateSolidBrush(RGB(0, 255, 0)); // Green fill
HGDIOBJ hOldBrush = SelectObject(hdc, hBrush);

// Define the rectangle coordinates
RECT rect = { 50, 50, 200, 150 };

// Draw the rectangle (filled and outlined)
Rectangle(hdc, rect.left, rect.top, rect.right, rect.bottom);

// Clean up GDI objects
SelectObject(hdc, hOldBrush);
DeleteObject(hBrush);
SelectObject(hdc, hOldPen);
DeleteObject(hPen);

// Release the device context
ReleaseDC(hWnd, hdc);
                    

Note: This is a simplified C++ GDI example.