PotatoShade — a minimal Iris shaderpack for very low-end PCs
==============================================================

WHAT THIS IS
-------------
A shaderpack for Minecraft Java Edition (Fabric + Sodium + Iris) that is
built specifically to be cheap to run. It does NOT:
  - render a shadow map (no second scene render — this is the single
    biggest cost in most shaderpacks)
  - use deferred lighting / G-buffer passes
  - use bloom, SSAO, volumetric fog/lighting, or reflections
  - allocate any extra color buffers beyond the default one

It DOES:
  - render the world exactly like vanilla (via simple passthrough
    "gbuffers" programs)
  - apply one cheap full-screen pass at the end (contrast, saturation,
    vignette, and an optional sharpen) to make the image look a bit more
    vivid than flat vanilla, controlled by a single "Intensity" slider

This is closer to a "vanilla+" color-grading pack than a full ray-traced
style shaderpack — that trade-off is intentional, because it's what
actually runs well on a GT 630 / i5-2400 class machine.

INSTALLATION
-------------
1. Confirm you have Fabric Loader with Fabric API, Sodium, and Iris
   installed and that Minecraft launches normally with them before adding
   any shaderpack.
2. Do NOT unzip PotatoShade.zip. Put the .zip file itself into:
     .minecraft/shaderpacks/
   (Options > Video Settings > Shaderpacks > "Open Shaderpacks Folder" from
   in-game will take you straight there.)
3. Launch Minecraft, open Options > Video Settings > Shaderpacks, and
   select "PotatoShade".
4. Click "Shader Options" to see the sliders/toggles described below.

OPTIONS (all editable in-game, no file editing needed)
---------------------------------------------------------
- Shader Intensity (0.0–2.0, default 1.0)
    Master strength control. 0 = looks like vanilla, 1 = the intended
    default look, 2 = strongest. This scales ALL effects below at once —
    this is the "intensity" control you asked for.
- Enable Contrast (default ON)
- Enable Saturation (default ON)
- Enable Vignette (default ON) — subtle edge darkening
- Enable Sharpen (default OFF) — cheap edge sharpen; turn on only if you
  have GPU headroom left, since it adds 4 extra texture reads per pixel
  on the final pass

RECOMMENDED SETTINGS FOR A GT 630 + i5-2400
---------------------------------------------
The shaderpack itself is as light as a shaderpack can reasonably be, but
your hardware is old enough (GT 630, a 2012-era entry-level GPU) that the
biggest performance wins will come from Minecraft/Sodium settings, not the
shader:
  - Render Distance: 8–10 chunks to start; raise only if FPS is stable
  - Simulation Distance: keep low (5–8)
  - Graphics: "Fast" (fewer transparent-leaf/overdraw costs)
  - Particles: Minimal
  - Entity Distance / Entity Shadows: lower / off
  - Cap your framerate (e.g. 60 or even 30) instead of leaving it
    uncapped — this reduces GPU/CPU heat and stutter on old hardware
  - Don't over-allocate RAM in your launcher profile; 3–4 GB is plenty
    for vanilla-scale play and over-allocating can cause longer garbage
    collection pauses on an older CPU
  - Consider pairing Sodium/Iris with Lithium, FerriteCore, and ModernFix
    (all Fabric mods) — they target CPU/memory overhead, which
    complements what this shaderpack does on the GPU side

IMPORTANT HONEST CAVEAT ABOUT YOUR GPU
-----------------------------------------
I can guarantee this shaderpack is about as cheap as a shaderpack can be,
but I can't fully guarantee it will run on a GT 630 specifically, because:
  - Recent versions of Iris/Sodium have minimum OpenGL/driver requirements
    that have crept upward over time, and very old GPUs like the GT 630
    can fall short of those requirements depending on the exact chip
    revision and how recent a driver NVIDIA ever shipped for it.
  - I don't have a way to test on your exact hardware/driver combo.
If PotatoShade fails to load or Iris itself refuses to start:
  1. Update to the newest driver NVIDIA still provides for the GT 630.
  2. Check Iris's and Sodium's mod pages (Modrinth/CurseForge) for their
     stated minimum OpenGL version and compare to what your driver
     reports (you can check with a tool like GPU-Z or `glxinfo` on
     Linux).
  3. If Iris truly won't run on this GPU at all, OptiFine (a separate,
     non-Fabric mod) tends to support older/lower OpenGL versions than
     Iris — that would be a fallback path, not a Sodium/Iris one.
  4. As a non-shader fallback, "vanilla+" resource packs (no shaders,
     just retextures) will always be lighter than any shaderpack.

TROUBLESHOOTING SHADER COMPILE ERRORS
-----------------------------------------
If Iris shows a red error screen after selecting PotatoShade, it will name
a specific file and line number (e.g. "final.fsh"). That means a typo or
GLSL syntax issue — check that file against what's here, or send me the
exact error text and I'll fix it.

FILE STRUCTURE
----------------
PotatoShade.zip
  shaders/
    final.vsh / final.fsh              <- the only pass that does real work
    gbuffers_basic.vsh / .fsh          <- untextured geometry (outlines etc.)
    gbuffers_textured.vsh / .fsh       <- unlit textured (sky, clouds, etc.)
    gbuffers_textured_lit.vsh / .fsh   <- lit textured (terrain, entities,
                                           hand, water, weather — covers
                                           most of what you actually see)
    shaders.properties                 <- optional menu layout only
  README.txt                           <- this file

WANT MORE?
------------
If you want this pushed further, I can add (each optional, each adds some
GPU cost — tell me which and I'll fold it in):
  - A soft directional "shading" tint pass (cheap fake sun-direction
    lighting, no shadow map)
  - A separate low/medium/high preset system beyond the single Intensity
    slider
  - A very lightweight fog color/density tweak
  - Underwater color grading
For comparison, if you ever want a more full-featured but still
low-end-friendly premade option to test against, look at "Vanilla Plus
Shaders" or the "Complementary Reimagined" pack's lowest preset — both are
real, actively maintained Java Edition (Iris/OptiFine) shaderpacks known
for having low-end-friendly settings.
