Frame and Debug API

Frame APIs define the coordinate space and flush recorded text/clip commands.

Functions

MGFX.StartPanel(panel, w, h)
MGFX.EndPanel()

MGFX.StartScreen(w, h)
MGFX.EndScreen()

MGFX.PushClip(x, y, w, h)
MGFX.PopClip()

local mask = MGFX.Mask(painter)
MGFX.Clip(mask, x, y, w, h, callback)
mask:Clip(x, y, w, h, callback)

MGFX.ShaderStatus()
MGFX.HasShaders()
MGFX.GetCapabilities(target)
MGFX.Supports(target, key)

Lux uses the same functions as lowerCamelCase methods under mgfx.api.

Common Template

GLua

function PANEL:Paint(w, h)
    MGFX.StartPanel(self, w, h)
    MGFX.RoundedBox(0, 0, w, h, 8, Color(20, 24, 32, 230))
    MGFX.EndPanel()
end

Lux

import * as mgfx from "@lux/mgfx"

local draw = mgfx.api

fn PANEL:Paint(w, h) {
  draw.startPanel(self, w, h)
  draw.roundedBox(0, 0, w, h, 8, Color(20, 24, 32, 230))
  draw.endPanel();
}

StartPanel

MGFX.StartPanel(panel, w, h)

Starts a panel-local MGFX frame. Coordinates inside the frame are relative to the panel, not screen coordinates.

Use this at the start of PANEL:Paint(w, h) and call EndPanel() before returning.

StartScreen

MGFX.StartScreen(w, h)

Starts a screen-space MGFX frame, usually from HUDPaint.

Clip Stack

MGFX.PushClip(x, y, w, h)
MGFX.PopClip()

PushClip clips subsequent drawing to a rectangular scissor region. It remains a cheap coarse clip, not a general shape mask.

For arbitrary-content shape clipping, define coverage and apply it with the callback-only Clip transaction:

local rounded = MGFX.Masks.Rounded({radius = 18, units = "local"})

MGFX.Clip(rounded, x, y, w, h, function()
    MGFX.Image(x - 20, y, w + 40, h, material)
    MGFX.Text("ANTIALIASED", "DermaLarge", x + w / 2, y + h / 2, color_white, TEXT_ALIGN_CENTER, TEXT_ALIGN_CENTER)
end)

MGFX.Mask(function(m, w, h) ... end) records custom vector coverage. The recorder exposes Draw/Union, Subtract, Intersect, Xor, and Invert; see the complete Coverage Masks, Clip, and Self-Clipping API for signatures, formulas, presets, invalidation, cache behavior, and shape children callbacks.

Clip does not use stencil. It captures the framebuffer before and after the callback and composites those snapshots through continuous shader coverage. This preserves antialiased edges even when the content mixes MGFX shapes, text, images, native surface drawing, and backdrop effects.

Each Clip costs two framebuffer copies and one bounded composite draw. The rectangular scissor is only a coarse performance bound; it does not define the shape edge. Clip requires the shader/render-target path, axis-aligned frame mapping, finite dimensions no larger than the framebuffer, and at most four nested scopes. It raises an error when unavailable instead of falling back to a binary clip. Do not call BeginCommands inside Clip or coverage recording; an active command batch is flushed before capture and resumed after compositing. Do not enter Clip while the caller owns a render.OverrideBlend or render.OverrideAlphaWriteEnable scope, because GMod exposes no getter with which MGFX could restore that descriptor.

Diagnostics

local status = MGFX.ShaderStatus()
print(status.ok, status.version, status.reason)

ShaderStatus reports whether the shader runtime is active. Fallback rendering is expected when shaders are unavailable or forced off.

Capabilities

if MGFX.Supports(MGFX.TARGET.POLY, "outerGlow") then
    MGFX.PolyEx(points, {outerGlow = {width = 12}})
end

Capabilities are useful for tools and optional feature probes. Normal drawing code usually does not need to branch on them.