Add texture-related funcs to pipeline

use sampler2DArray to handle texture in shader

prevent recreate_swapchain_and_views from exploding when window is minimized

rename gen_command_buffer to record_command_buffer

rename renderer methods begin/end to begin_frame/end_frame

renderer: handle frame future internally

allow dead code in unused perspective cam lib

rename sampler var

rename buffer vars

render a white texture from a sampler

make Timing better

set sandbox window not resizable

adjust camera movement based on zoom level

remove unused code

implement camera zoom using scroll