Three things the first Vulkan frames on the RTX 3070 Ti showed against OpenGL on the same PC:
- Exposure: the adaptation pass reads the HDR scene's smallest mip, and a render target made
without pixels had one level, so exposure came from a single texel. A target asked for mipmaps
now grows a full chain (level 0 kept), and passes draw through level-0 views keyed by the
image's generation.
- Foliage: the depth prepass and the lit pass (depth EQUAL) are different variants. Vulkan vertex
stages now declare an invariant gl_Position so both land on the same depth.
- Alpha to coverage is enabled only on a multisampled pass. OpenGL ignores it without MSAA; Vulkan
with one sample dropped every fragment under half alpha.
vk_resources also checks a big-endian 16-bit RGB upload (a normal map). VKRES OK; ludic-dev test
140 passed; the PC's Vulkan frame is validation-clean; OpenGL frames byte-identical at the five
viewpoints with 59 self-tests passing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
gpu_vk_res.ludic gains what gpu.ludic's texture and buffer handles stand for on Vulkan:
- gvk_tex_storage / _upload / _mips / _read / _release: an image and view per handle, a full mip
chain when pixels come with it (the renderer asks for mipmaps after the upload) and one level
for a target, every level in SHADER_READ_ONLY between uses. Uploads are converted to what the
image stores: a missing alpha filled opaque (three-channel formats are stored with four), 16-bit
PNG samples byte-swapped when the unpack state says so, 32-bit float HDR halved into half
floats. Mips are blitted down level by level; a read-back brings level 0 home.
- gvk_sampler: one VkSampler per filter / wrap / compare / anisotropy combination, made when first
asked for, with GL's defaults where the renderer set nothing.
- gvk_buf_*: vertex, index and instance buffers behind one handle, kept when an upload fits.
Host-visible while the backend comes up.
gpu_vk.ludic switches on anisotropic sampling where the device has it and reads its limit.
examples/rendering/vk_resources.ludic checks it all: VKRES OK, validation-clean, every allocation
freed, on the RTX 3070 Ti (16x anisotropy) and on MoltenVK. One run on the Mac crashed while a
headless game run was using the GPU and did not come back in two reruns. OpenGL frames
byte-identical at the five viewpoints; 59 self-tests pass.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The first part of the Vulkan side of gpu.ludic, not yet reached from the renderer: gvk_init
brings up the instance (portability enumeration where offered), the first discrete GPU, a
graphics queue and a device with the Tier 1 floor switched on (dynamic rendering,
synchronization2, descriptor indexing, timeline semaphores), and says why when it cannot so
the caller stays on OpenGL. gvk_mem_type / gvk_alloc pick and allocate memory (one allocation
per resource while the backend comes up), and gvk_once_begin / gvk_once_end carry uploads,
bakes and read-backs through submit and wait.
examples/rendering/vk_device.ludic runs it alone: VKDEVICE OK and validation-clean on the RTX
3070 Ti and on MoltenVK.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A Slang vertex and fragment shader draw a triangle into an image with dynamic rendering (no
render pass object: the pipeline names its colour format), image barriers move it to the
attachment and transfer layouts, and vkCmdCopyImageToBuffer reads it back into a PPM. It is
the path the Vulkan renderer's passes and screenshots take.
The corner comes from SV_VulkanVertexID: Slang compiles SV_VertexID to gl_VertexIndex -
gl_BaseVertex, which declares the draw-parameters capability.
Validation-clean and VKTRIANGLE OK on the RTX 3070 Ti (Windows) and the M4 Pro (MoltenVK),
13824 pixels covered on both.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
gpu_manifest.ludic loads shaders/spv/manifest.txt and answers what a backend asks while drawing:
which variant a program built by r3d_program is, where a uniform lives in its stage's block,
which binding a sampler has, what the vertex inputs are. examples/rendering/vk_manifest.ludic
resolves every program in variants.list against it (45 of 45) and checks a few offsets and
bindings. Nothing imports it yet.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
ludic-dev vkgen reads vk.xml into runtime/native/vk_api.ludic (constants, every struct's
<Struct>_sizeof and <Struct>_<field> offsets, one extern per command) and vk_thunks.ll.
Every size and offset was compiled against the SDK's C headers; `ludic-dev test` checks the
tracked files against the registry wherever the Vulkan SDK is installed.
vk_win.ll (vulkan-1.dll) and vk_mac.ll (libvulkan.1.dylib, MoltenVK) open the loader at run
time, so a program built with Vk.* starts on a machine without Vulkan. ludicc and ludic
build link both for any program that uses Vk.*. The seeds are regenerated for the new
compiler.
vk_probe reports what a machine's Vulkan can do; vk_compute dispatches a Slang compute
shader and reads the picture back, clean under the validation layer on an RTX 3070 Ti and
on an M4 Pro through MoltenVK.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
terrain_reload/terrain_unload release one map's height field, survey, photograph
and patch bounds and generate another at any TERRAIN_HALF; scatter_clear_all
(with streams), actor_clear_all, col_reset and mesh_free empty the scene;
water_body_add/water_bodies_clear draw several still-water planes with one
reflecting; terrain_sea separates the coast's sea level from the carved lake's,
and grass keeps off both. Fixes CDLOD patch bounds for TERRAIN_HALF != 4096 and
water_init leaking a mesh and program per call. examples/rendering/reload.ludic.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
`Gl.*` binds the whole OpenGL 4.1 core API — every entry point of the
platform gl3.h with every GL_* constant, generated by `ludic-dev glgen`
with per-call ABI thunks. Windowed builds get an NSOpenGLContext on the
existing window at Retina resolution; headless builds render into an
offscreen CGL context, so a program that uses Gl.* renders and
screenshots identically under the test harness. It links gl.ll, the
thunks and OpenGL.framework only when used; every other build stays
byte-identical.
packages/ludic.render3d is a physically based renderer written on that
surface: HDRI image-based lighting, GPU-generated terrain with scanned
PBR materials, CDLOD, cascaded shadows, glTF with skinning, instanced
vegetation with impostors, procedural grass, water, SSAO, and an HDR
pipeline with bloom, auto-exposure and ACES.
It also carries this session's work on it: the terrain at half its cost
(10.3 -> 5.4 ms of frame), the streaming hitch that got worse the longer
you played, a resize that emptied the world, and the packaging that lets
a game use the renderer from its own repository — `ludic assets`, the
material manifest shipping with the package, and shader lookup falling
back to the install root. See changes/ for each, with its numbers.
The camping game that drove all of it has moved out to its own
repository, Maroon Lake; examples/rendering/smooth.ludic stays as the
renderer's example here.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Repository-cleanup / DX pass folding three tracker items into one coherent
change, verified green end to end (`bin/x test` 49/0, `bin/x selfhost-test`
29/0, `bin/x test-tools` 29/0).
#28 — curate & categorise examples/
- 42 flat entries regrouped into intent-revealing subdirs: games/, rendering/,
ecs/, events/, networking/, lang/, library/ (was lib/).
- chronorift dir-vs-file duplication resolved: the entry file and its import
modules now live together under games/chronorift(.ludic).
- Every path reference updated repo-wide (test runner, editor-tool drivers,
docs/site, design docs).
- New examples/README.md indexes the whole set with run commands.
- Showcase examples without a self-asserting entry (hello, events, net_rt) now
get a compile-only rot guard in `bin/x test`, so nothing here rots silently.
#30 — text-diffable golden baseline
- The 4 binary selfhost/golden/*.ppm blobs are replaced by a single
selfhost/golden/renders.sha256 manifest (SHA-256 per render). Hashes are
byte-identical to the old PPMs, so the baseline is unchanged — only its form.
- game_case now compares framebuffer hashes; a regression shows as a changed
hex line in review, not "binary files differ".
- New `bin/x golden` regenerates the manifest deliberately (review with
`git diff selfhost/golden/renders.sha256`).
#27 — PPM & asset handling
- Headless renders now write build/out.ppm, never the repo root; `x app`,
`x clean`, messaging and .gitignore updated to match. Nothing is written to
the working root any more.
- Redundant local Kenney .zip archives removed (the art ships extracted;
.gitignore already excludes *.zip). CC0 License.txt files retained.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
