Phase 4 / Task 3: Remove direct VulkanContext coupling from WorldRenderer

[MichaelFisher1997]

Goal

Remove direct VulkanContext coupling from WorldRenderer.

Scope

• src/world/world_renderer.zig

Work

• Replace direct VulkanContext access with the minimum required data
• Reduce or eliminate @ptrCast use against Vulkan internals
• Keep MDI, CPU culling, and GPU culling paths working

Acceptance criteria

• WorldRenderer no longer depends on backend internals directly
• Rendering output is unchanged

Parallel-safe

Yes

[github-actions]

Analysis Comment

Classification: Refactoring / Architecture Task

This is a legitimate architecture improvement. The task is well-scoped to src/world/world_renderer.zig, but the exploration reveals important context that should inform implementation:

Validation of Findings

The analysis confirms the coupling:

• Line 137: @ptrCast(@alignCast(rhi.ptr)) extracts *VulkanContext
• Lines 422-423: Direct access to vk_ctx.gpass.g_pass_extent
• Line 424: Direct call to vk_ctx.depth_pyramid.isValid()

Scope Consideration

The task is appropriately scoped for WorldRenderer specifically, but be aware that CullingSystem and GpuMesher have deeper and more systemic coupling to VulkanContext (they access vulkan_device, frames, resources.buffers directly). Full GPU-driven rendering decoupling would require a larger effort.

Suggested Implementation Path

1. Add to IRenderContext VTable (in src/engine/graphics/rhi.zig):

   • getGPassExtent() [2]u32 — for screen dimensions used in culling dispatch
   • isDepthPyramidValid() bool — to check temporal culling validity

2. Implement in rhi_vulkan.zig — forward to the underlying VulkanContext.gpass and depth_pyramid

3. Update WorldRenderer — replace the two direct accesses with RHI method calls

This keeps MDI, CPU culling, and GPU culling paths functional while eliminating WorldRenderer's direct VulkanContext dependency.

opencode session  |  github run