Appendix G. Device Guide
This document lists various notes, capabilities, and limitations about each Visualize driver interface. These should be taken into consideration when programming your application as not every driver interface is as capable as the others. Some have external software dependencies, and some are not compatible with Visualize (due to bugs in the vendor drivers or other limitations). See the graphics card information page for more details.
In addition to conventional on-screen rendering, all driver interfaces additionally support hardware-accelerated rendering to a memory buffer. For information on how to set up an offscreen rendering context, see section 7.2 of the Core Graphics Programming Guide.
All Visualize windows are double-buffered.
The DirectX11 driver is supported in Windows 10, 8 and 7. For Windows Vista, DirectX11 requires Service Pack 2+, and installation of the most current Vista platform updates as of October 1, 2013.
In your code, the DirectX11 interface can be selected using the Window::Driver::DirectX11 enum value.
Use of this driver allows the developer to query and select which GPU to use when running on a system that has multiple GPUs. A common example would be running on a laptop which has both an integrated GPU and a discrete graphics card, which often yield significant differences in performance and power consumption.
Users can query GPUs using HPS::Database::ShowAvailableGPUs().
Users can select which GPU to use with the new function SetPreferredGPU(), which is available in the following classes:
In order to use the DirectX11 driver, the d3dcompiler DLL must be made available in the execution environment of the target machine. We distribute this file with the Visualize package. If you are building with Visual Studio 2013 or 2015 (8.1 SDK or later) you need to include the file d3dcompiler_47.dll.
OpenGL2 is a shader-based driver interface that requires the host platform to have OpenGL 3.2+ or OpenGL ES 3.0+. The Visualize OpenGL2 driver interface is supported on all platforms.
- Post process effects (bloom, fast silhouettes, ambient occlusion, and depth of field) are not currently supported on iOS or Android due to GPU limitations on current devices.
In your code, the OpenGL2 interface can be selected using the Window::Driver::OpenGL2 enum value.
The OpenGL2Mesa driver is a software driver interface. This driver is functionally equivalent to our other shader drivers, however, its performance is reduced since it doesn't make use of the GPU. It's meant to provide a fallback driver on a system where no other hardware driver is available.
Please note that on Windows 10 systems, Microsoft provides a DirectX11 software fallback in case there is no GPU available in the execution environment, so this driver is normally only useful for other operating systems. On Linux, for example, it would be useful if the user doesn't have a GPU and is unable to install a Mesa driver on the system.
The OpenGL2Mesa driver is provided as a separate library, and is supported on Windows and Linux systems only. We also include a 32-bit Mesa driver binary for Windows (but not for Linux). The relevant files are named as follows:
In addition to the driver file itself, there's another dependency you must include. This is named libHGL.so on Linux and hopengl32.dll on Windows. To use the Mesa driver, both of these files need to be in the application's path (or LD_LIBRARY_PATH) at runtime.
The Metal driver is available for Apple platforms, for both desktop (Intel and ARM) and mobile.
Beyond selecting it, there is some application-level code needed to use the Metal driver - please refer to the samples or sandboxes for the relevant code. There, you can see how the NSView-derived (for desktop) or UIView-derived (for mobile) view classes work. Essentially, the view must be backed by a CAMetalLayer.
- No double precision support.
- XOR overlays will likely look different than OpenGL2 or DX11.
- Ambient Occlusion will look different than OpenGL2 or DX11 as it uses a different algorithm.
- "Fastest" marker drawing will almost certainly have a different max point sprite size than OpenGL2 or DX11.