D3D10 and OpenGL provide a feature called 'dual source blending' which allows devs to implement destination alpha in a straightforward way. It isn't perfect and works well enough for most games, but it's a fairly complex chunk of code which is poorly contained, spreading across different files and messing up interfaces. There's only one D3D9 workaround: render things twice (dual-pass rendering). It can be faked in D3D9 with a bunch of hacks, but it is extremely difficult, invasive, and inaccurate.ĭ3D11 and OpenGL properly emulating point size D3D9 loves to make things biggerĭestination Alpha: Destination Alpha is a Wii GPU feature used by many games, but it can't be implemented cleanly in D3D9. D3D11 and OpenGL can emulate it with geometry shaders, but Direct3D9 doesn't support it at all.

Line width / point size - Line width and point size are features of GameCube and Wii GPUs.

All kinds of modern functions are simply not possible in D3D9. The D3D9 backend was as fast as it was because it simply didn't emulate certain effects. Its age means that many modern features are simply not available for it, features that Dolphin needs for GameCube and Wii emulation. But Direct3D9 is very old it was released in 2001 and received its last update in 2004. On AMD and Integrated Graphics cards, it is by far the fastest backend. D3D9: Inherently Flawed ¶ĭolphin's D3D9 backend was mostly known for its speed.

This is why the D3D9 backend was removed. With D3D9 removed, the developers can focus their effort on making the emulator better instead of pandering to the ever growing demands of a flawed backend. D3D9 is inherently flawed, and working around its problems wasted time and slowed development. While it was enjoyed by users, it was a source of endless frustration for the developers. For the longest time, D3D9 was considered Dolphin’s fastest backend and was a favorite of Windows users.

As many people have noticed, revision 4.0-155 removed D3D9 as a video backend, leaving D3D11 and OpenGL as the sole hardware backends in Dolphin.

Dolhpin requires opengl 3.3