- gfx::pipeline gains bind_vec3/bind_float for passing arbitrary
uniforms to shaders (used for light position/color)
- scene base gains on_mouse_drag virtual hook; cuber.cpp polls
left-mouse delta each frame and forwards it to the active scene
- cornell_box scene: 5-wall room (red/green/white), two pre-rotated
white boxes with proportions from the original paper, an unlit
ceiling light panel, and a point-light Lambert shader
- left-click drag orbits the camera around the scene origin;
pitch is clamped to ±80° to prevent gimbal flip
- key 3 / --scene cornell_box selects the scene
Add cbt/gfx layer (pipeline + render_target) inspired by Sokol but
C++-friendly with RAII and pipeline_desc. Supports building full
graphics pipelines (VS/IA/raster/PS/OM), render-to-texture (FBO),
and post-processing steps (scene -> RT -> fullscreen quad with
sampler + vignette).
- Depth/state/viewport/texture cleanup for reliable scene switching.
- Updated cube/sphere to demonstrate (sphere uses RT+post).
- Vulkan backend easy via PIMPL in impl (same public API).
- Fixed depth test, viewport restore, and state leakage on switch.
Followed coding conventions (snake_case, trailing returns, east const,
include order, no ; after ns/class, etc.).