Engine shader inputs

Enhanced programs read engine-owned buffers as well as material parameters. A constant’s name is a lead; the lanes actually read and the arithmetic using them constrain its role more precisely. Observed · compiled-program inspection

Constant	Inspected use	Confidence
globalScreenSize.xy	VS_SSAO multiplies UV by half of XY to produce pixel coordinates	Observed
globalScreenSize.zw	The same program offsets UV by twice Z or W for whole-texel steps	Observed
gDirectionalAmbientColour.xyz	Ambient colour multiplied by a directional normal term in PS_lightTile_ambient	Observed
gDirectionalAmbientColour.w	Vertex-colour scale through (w-1)*fade + 1 in VS_TransformD	Observed
gDynamicBakesAndWetness.z	Scales an up-facing wetness term in parallax effects; also participates in vehicle dirt blending	Observed
gDynamicBakesAndWetness.xy	Ped coefficient pair in y*(0.5 + 0.5*N.z) + x	Observed
gLightArtificialIntAmbient0.w	Added to a vertex-colour term in G-buffer target 3 X	Observed
globalScalars.x	The factor an instance’s visibility is faded by, 1 where fully shown; see below	Observed
globalScalars2.z	Enters both a 1-z wetness term and a floor(128*z) state-byte expression	Observed
globalScalars2.z	In VS_TransformD_749c0f99, with f = saturate(distance² * 0.000004), scales COLOR0.x by 1 + (gDirectionalAmbientColour.w - 1) * saturate(f - z) and COLOR0.y by 1 + (w - 1) * saturate(1 - f - z)	Observed
globalScalars2.y	VS_Transform_SeeThrough_5c7539b4 draws its geometry only where y > 0 and outputs saturate(clip.w / y)	Observed
globalScalars2.x	The phase of a sine vertex motion: sin(position-derived phase + 2.5 * x) in VS_Transform_SeeThrough_5c7539b4, and in VS_PedTransformD_bddf08c5	Observed

globalScalars2 is row 13 of the miscellaneous globals buffer (offset 208). Its lanes do different jobs in different programs, so it is not one wetness scalar, and a program that loads all four lanes need not use all four (one sample loads w and never uses it). Observed · compiled-program inspection What writes it on the CPU, and its values, are not known. Unknown

The natural interpretation of globalScreenSize.zw is reciprocal width and height, but the sampled usage does not itself show the CPU writing 1/x and 1/y. Inferred

In PS_DeferredTextured_6b2704e5, the state byte uses ((stipple << 6) & 192) combined with 7 or 23 selected by whether antighosting exceeds one half. These values come from lanes named gStippleAlpha and gTemporalAntiGhosting, rather than from material albedo. Observed · compiled-program inspection

globalScalars.x

Lane x of globalScalars (row 12 of the frame-constant buffer a program binds; register 5 in most programs, 2 or 4 in a few) is read by 4,386 of the 12,286 distinct programs of the install’s shader database: 4,372 pixel programs and 14 compute programs, and no vertex program. Observed · a value-graph walk from the word to every output lane, discard condition and write, over all programs counted by distinct bytecode; 7 programs could not be lifted into a value graph and are not counted

Every use is multiplicative or monotone and leaves the value unchanged where the lane is 1, so the lane reads as the factor the engine fades an instance’s visibility by (1 where it is fully shown, 0 where it is gone). The programs apply it in five ways, counted by the place the word reaches: Observed · same walk; the 59 programs of the last three rows and of the add-first group read by hand in their lifted text

Where the word goes	Pixel programs	Compute programs
An alpha lane of a colour target and/or an alpha-test discard, nearly always as a factor of the alpha (alpha = texture.w * vertex.w * x); 979 of them also quantise it into the 3-bit alpha of the G-buffer state byte, where 7 is opaque	4,224	0
Target 1 z of the reflection G-buffer programs (PS_MirrorReflectionGBuffer, PS_ReflectionGBuffer, each with and without AlphaClip; 28 each), which have no alpha lane: the product colour.z^2 / 16 * k * x in the emission slot	112	0
The depth of a depth-based alpha test (PS_LinearDepth: x * alpha - ref steers the depth output)	27	0
A manual blend with the scene behind, lerp(scene, lit colour, x * k) in the colour lanes with alpha 1 (PS_Textured_*, *_DOF)	9	0
The alpha of the reflection image the mirror compute programs store (cs_mirror_reflection*)	0	14

No program uses the word in any other way. Observed · same walk

The shader source CodeWalker ships keeps a commented legacy bytecode line mul o0.w, r0.y, globalScalars.x for the alpha of its basic pixel program, and its own port omits the factor. It gives the lane no name. Sourced · CodeWalker

Engine textures

Programs also sample textures the engine binds, named in each program’s own SGD2 table (28-byte texture records, the names checked against their stored joaat hashes). In the programs the Legion Square materials bind:

Register (space 0)	Name	Programs	Confidence
t1	gReflectionTex	glass programs	Observed
t2	gFogRayTex	PS_Textured_Zero_7903a05e_Wrapped and others	Observed
t3	g_BlueNoise	PS_DeferredTextured_AlphaClipC	Observed
t4, t5, t6	g_ReflectionAlphaDepthTex, g_ReflectionAlphaResult, gReflectionTexClipped	glass programs	Observed
t7	gCSMShadowTexture	PS_Textured_Zero_7903a05e_Wrapped and others	Observed
t14, t15, t17, t19, t22	g_BlendTexture, g_ReflectionTex2, g_WaterBumpTexture, g_RefractionTexture, g_LightingTexture	PS_WaterFountain_7903a05e_Wrapped	Observed

Observed · each bound program’s table read and its name, hash and register checked against the material’s binding These are the engine’s names for the slots. No material stores a texture for them, so what the engine puts there at run time is not in the data. Inferred

How does the CPU populate each global?

Program reads establish a constant-to-output dependency. They do not establish every writer, update cadence, default or physical unit of the constant. Unknown