56355231bd
This change does three main things. First, it adds an option to the Engine Builder to pick the feature level at which to instantiate Filament. The only real practical purpose of allowing this is to be able to instantiate at feature level 0. Secondly, it allows feature level 0 to properly work on non-ES2 devices. Thirdly, it changes both Android and desktop hellotriangle samples to explicitly opt-in to feature level 0. Unfortunately, feature levels are used in two different, somewhat contradictory ways presently in Filament, which can make reasoning about this change a bit confusing. From a client perspective, feature levels refer to buckets of capabilities which are guaranteed to be supported. Internally, there is a separate "feature level" stored internally at the Driver subclass level which generally corresponds to the maximum supported feature level, but is also referenced when activating workarounds for limited devices. For example, Uniform Buffer Objects are not supported in ES2, however, Filament supports emulating them such that the client does not need to care at all; a supported feature is a supported feature. But internally, Filament uses this "Driver" feature level to determine whether or not a given workaround is needed. There were several cases where the "active feature level" was being examined in order to activate these workarounds rather than the "driver feature level", which was incorrect. Why should non-ES2-only devices want to activate feature level 0? Allowing this behavior 1. makes feature level 0 more consistent with the behavior of other feature levels and 2. allows clients a layer of validation that their software will work on all devices supported by Filament if they explicitly opt into it. Consistency: Filament guarantees that any given device which supports a given feature level will also support running on every feature level below, except for feature level 0. This change removes that exception. Validation: It's not perfect, and there will likely be bugs and unexpected differences in behavior between ES2 and non-ES2 devices that crop up in the future between two devices running on the same feature level. However, it's at least a basic high level layer of validation that enables more rapid testing workflows directly via desktop versions of Filament rather than having to fiddle with something like ANGLE to get perfect GLES 2.0 compliance. Additionally, it expands options for automated testing (with the same caveats). This change has been tested on both the desktop and Android versions of hellotriangle.
17 lines
288 B
Plaintext
17 lines
288 B
Plaintext
material {
|
|
name : BakedColor,
|
|
requires : [
|
|
color
|
|
],
|
|
shadingModel : unlit,
|
|
culling : none,
|
|
featureLevel : 0
|
|
}
|
|
|
|
fragment {
|
|
void material(inout MaterialInputs material) {
|
|
prepareMaterial(material);
|
|
material.baseColor = getColor();
|
|
}
|
|
}
|