forge-gpu

Add PBR texture loading with separate roughness/metallic support to an SDL GPU project using forge_scene.h

Add Cook-Torrance PBR shading with GGX, Schlick-GGX, and Schlick Fresnel to an SDL GPU project alongside forge_scene.h

Add instanced grass rendering with segmented blades, wind animation, LOD density rings, and terrain LOD with geomorphing to an SDL GPU project

Add procedural noise texture generation to the asset pipeline — C tool, Python plugin, web UI with live preview

Add an asset pipeline lesson — hybrid Python + C track for asset processing, procedural geometry, and web frontend

Add an audio lesson — sound playback, mixing, spatial audio, DSP effects, with SDL GPU scenes and forge UI

Run a quality review pass on a lesson before publishing, catching recurring issues found across project PR history

Scaffold a new GPU lesson using forge_scene.h for the rendering baseline

Add a physics lesson — particle dynamics, rigid bodies, collisions, constraints, rendered with SDL GPU

Code quality, correctness, and documentation review for physics lessons — run before dev-final-pass

Update the current working branch with the latest main. Fetches origin/main, updates local main, and rebases the current branch onto main.

Add an engine/toolchain lesson — build systems, C fundamentals, debugging, project structure

Add a UI lesson — TTF parsing, font rasterization, immediate-mode UI controls, layout

Add atlas-based texture rendering to an SDL GPU project. Load atlas metadata from JSON, remap UVs in the fragment shader, and reduce texture bind state changes.

Create a matplotlib diagram for a forge-gpu lesson using the project's dark theme and visual identity

Analyze the working tree, stage relevant changes, create a branch if needed, commit, and open a pull request

Review all project documentation for staleness — READMEs, skills, plans, CLAUDE.md, project structure trees

Ask CodeRabbit to verify and resolve each unresolved feedback thread on a PR. Use when CodeRabbit posts "No actionable comments" but old threads remain open, blocking approval.

Handle automated PR review feedback and merge when ready

Add cascaded shadow maps with PCF soft shadows to an SDL GPU project

Add deferred decal projection to an SDL GPU project. Render projected decals onto scene geometry using depth reconstruction, inverse view-projection transforms, local-space bounds checking, soft-edge fading, G-buffer normals, Blinn-Phong lighting, and shadow map sampling.

Add a projected-texture (gobo/cookie) spotlight with cone falloff, shadow map, and pattern projection to an SDL GPU project

Add depth-based distance fog to an SDL GPU project. Supports linear, exponential, and exponential-squared modes. Fog is applied in the fragment shader after lighting, blending the lit color toward a fog color based on camera distance.

Add tangent-space normal mapping to an SDL GPU project. Extends the vertex layout with tangent vectors, constructs a TBN matrix in the vertex shader, and samples/decodes normal maps in the fragment shader for per-texel surface detail.

Use the forge-gpu asset pipeline library — a Python package installed via uv for scanning, fingerprinting, processing, and bundling game assets with a plugin architecture. Use when working with pipeline code, writing plugins, processing textures/meshes/animations, bundling assets, or extending the pipeline CLI.

Add per-asset import settings with TOML sidecar files, three-layer merge (schema → global → per-asset), a settings editor form with type-specific controls, and single-asset re-processing from the web UI. Use when someone needs configurable per-file processing overrides, settings UI, or sidecar-based configuration.

Add a GPU-driven particle system with compute shader simulation, billboard rendering, texture atlas animation, and blending modes to an SDL GPU project.

Acknowledge information from the user without taking action

Answer a question with facts only. No changes, no suggestions, no opinions. Brief and precise. Usage: /dev-ask <question>

Explain something in detail with investigation. No changes, no suggestions, no opinions. Facts and technical depth only. Usage: /dev-explain <topic>

Execute exactly what was asked. Nothing more, nothing less. No assumptions, no extras, no personality. Usage: /dev-request <instruction>

Validate diagram correctness against the lesson README before pushing

Add per-material Blinn-Phong lighting with ambient, diffuse, specular colors and shininess. Use when someone needs to render multiple objects with distinct material appearances, add material property systems, or extend basic lighting with per-object parameters in SDL3 GPU.

Add Sobel edge detection on G-buffer data (depth + normals via MRT), stencil-based X-ray vision with depth_fail_op, and Fresnel ghost silhouettes with additive blending to an SDL GPU project.

Draw colored geometry with vertex buffers, shaders, and a graphics pipeline using SDL3 GPU API. Use when someone needs to render vertices with per-vertex attributes.

Add HDR rendering and tone mapping to an SDL GPU project. Render to a floating-point render target, then tone map to the swapchain with Reinhard or ACES filmic operators. Includes exposure control and fullscreen blit pass.

Add GPU-driven indirect drawing with compute-based frustum culling to an SDL GPU project. A compute shader tests bounding spheres against frustum planes and writes indirect draw commands — the CPU never decides what to draw. Uses SDL_DrawGPUIndexedPrimitivesIndirect with per-object storage buffers and the first_instance offset pattern for portable instance identification.

Add stencil buffer testing to an SDL GPU project. Configure depth-stencil textures with stencil bits, set up stencil state on pipelines, and use stencil operations for portals, outlines, and per-pixel masking.

Run a local code review using the CodeRabbit agent before pushing to catch issues early

Add morph target (blend shape) animations with pipeline assets to an SDL GPU project using ForgeSceneMorphModel.