Direct3DRMDevice and Direct3DRMDeviceArray
All forms of rendered output must be associated with an output device. The device object represents the visual display destination for the renderer.
The renderer's behavior depends on the type of output device that is specified. You can define multiple viewports on a device, allowing different aspects of the scene to be viewed simultaneously. You can also specify any number of devices, allowing multiple destination devices for the same scene.
Retained Mode supports devices that render directly to the screen, to windows, or into application memory.
For related information, see the IDirect3DRMDevice interface.
Quality
The device allows the scene and its component parts to be rendered with various degrees of realism. Each mesh can have its own quality, but the maximum quality available for a mesh is that of the device.
An application can change the rendering quality of a device by using the IDirect3DRMDevice::SetQuality and IDirect3DRMMeshBuilder::SetQuality methods. To retrieve the rendering quality for a device, it can use the IDirect3DRMDevice::GetQuality and IDirect3DRMMeshBuilder::GetQuality methods.
Retained Mode supports two color models: an RGB model and a monochromatic (or ramp) model. To retrieve the color model, an application can use the IDirect3DRMDevice::GetColorModel method.
The RGB model treats color as a combination of red, green, and blue light, and it supports multiple light sources that can be colored. There is no limit to the number of colors in the scene. You can use this model with 8-, 16-, 24-, and 32-bit displays. If the display depth is less than 24 bits, the limited color resolution can produce banding artifacts; you can avoid these artifacts by using optional dithering.
The monochromatic model also supports multiple light sources, but their color content is ignored. Each source is set to a gray intensity. RGB colors at a vertex are interpreted as brightness levels, which (in Gouraud shading) are interpolated across a face between vertices with different brightnesses. The number of differently colored objects in the scene is limited; after all the system's free palette entries are used up, the system's internal palette manager finds colors that already exist in the palette and that most closely match the intended colors. Like the RGB model, you can use this model with 8-, 16-, 24-, and 32-bit displays. (The monochromatic model supports only 8-bit textures, however.) The advantage of the monochromatic model over the RGB model is simply performance.
It is not possible to change the color model of a Direct3D device. Your application should use the IDirect3D::EnumDevices or IDirect3D::FindDevice method to identify a driver that supports the required color model, then specify this driver in one of the device-creation methods.
Window Management
For correct operation, applications must inform Retained Mode when WM_MOVE, WM_PAINT, and WM_ACTIVATE messages are received from the operating system by using the IDirect3DRMWinDevice::HandlePaint and IDirect3DRMWinDevice::HandleActivate methods.
For related information, see IDirect3DRMWinDevice.