RenderingDevice: Index offset incorrectly applied twice

[pkdawson]

Tested versions

Reproducible in 4.3.dev1 and later.
Not reproducible in 4.2.1 and earlier.

System information

Godot v4.3.dev.mono (89cc635) - Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4070 Ti (NVIDIA; 31.0.15.4629) - 13th Gen Intel(R) Core(TM) i5-13600K (20 Threads)

Issue description

The bug described in #68293 has crept back in during the RenderingDevice refactor, affecting both Vulkan and Direct3D 12. The index array is bound with an offset, but then that offset is applied again when drawing, giving the wrong result.

godot/servers/rendering/rendering_device.cpp

Lines 4260 to 4262 in 89cc635

	dl->validation.index_array_offset = index_array->offset;
	driver->command_render_bind_index_buffer(dl->command_buffer, index_array->driver_id, index_array->format, index_array->offset);

godot/servers/rendering/rendering_device.cpp

Line 4373 in 89cc635

driver->command_render_draw_indexed(dl->command_buffer, to_draw, p_instances, dl->validation.index_array_offset, 0, 0);

The same solution (#68303) fixes this. The p_offset parameter in command_render_bind_index_buffer could just be removed, but maybe it's needed for console graphics APIs, I dunno.

Steps to reproduce

Run the MRP, check whether there's a nice red-green-blue triangle centered in the screen.

Minimal reproduction project (MRP)

index-bug.zip

[clayjohn]

I think your proposed solution is correct. IIRC Vulkan is unique in that it lets you specify offsets at draw time. If other platforms need the offset at draw time, we can make the change in the Vulkan RDD and just ignore the p_offset parameter

CC @RandomShaper