Adds DrawElementsIndirectCommand struct (20-byte layout for
glMultiDrawElementsIndirect). Replaces _instanceVbo field on
WbDrawDispatcher with three buffers: _instanceSsbo (mat4[]),
_batchSsbo (BatchData[]), _indirectBuffer (DEIC[]). Adds BindlessSupport
constructor parameter — non-null required since the dispatcher is only
constructed when WB foundation is on (which implies bindless is present
per Task 6 capability detection).
Existing Draw() method substitutes _instanceVbo -> _instanceSsbo for
compile. Behavior is temporarily wrong (SSBO bound as ArrayBuffer for
per-vertex attribs); Tasks 9-10 fully rewrite the draw loop and the
per-frame uploads to use BindBufferBase + glMultiDrawElementsIndirect.
GameWindow construction site updated to add _bindlessSupport guard and
pass it as the new last argument to the constructor. Dispatcher is only
constructed when bindless is guaranteed present.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
