Control Registers¶

API reference for GPU control register structs in the opengnm PS4 GNM library. These structs configure blend, depth/stencil, primitive setup, and viewport transform state.

Header: gnm_controls.h

GnmBlendControl¶

Controls per-target blending configuration for color and alpha channels.

typedef struct {
    bool blendenabled;
    GnmCombFunc colorfunc;
    GnmBlendOp colorsrcmult;
    GnmBlendOp colordstmult;
    GnmCombFunc alphafunc;
    GnmBlendOp alphasrcmult;
    GnmBlendOp alphadstmult;
    bool separatealphaenable;
} GnmBlendControl;

Field	Type	Description
`blendenabled`	`bool`	Enable blending for this target
`colorfunc`	`GnmCombFunc`	Color blend combination function
`colorsrcmult`	`GnmBlendOp`	Color source blend multiplier
`colordstmult`	`GnmBlendOp`	Color destination blend multiplier
`alphafunc`	`GnmCombFunc`	Alpha blend combination function
`alphasrcmult`	`GnmBlendOp`	Alpha source blend multiplier
`alphadstmult`	`GnmBlendOp`	Alpha destination blend multiplier
`separatealphaenable`	`bool`	Enable separate alpha blending

GnmDbRenderControl¶

Controls the DB (Depth Block) render state, including clears, HTile, and copy operations.

typedef struct {
    bool depthclearenable;
    bool stencilclearenable;
    bool htileresummarizeenable;
    bool depthwritebackpol;
    bool stencilwritebackpol;
    bool forcedepthdecompress;
    bool copycentroidenable;
    uint8_t copysampleindex;
    bool copydepthtocolorenable;
    bool copystenciltocolorenable;
} GnmDbRenderControl;

Field	Type	Description
`depthclearenable`	`bool`	Enable depth clear
`stencilclearenable`	`bool`	Enable stencil clear
`htileresummarizeenable`	`bool`	Enable HTile resummarize
`depthwritebackpol`	`bool`	Depth write-back policy
`stencilwritebackpol`	`bool`	Stencil write-back policy
`forcedepthdecompress`	`bool`	Force depth decompression
`copycentroidenable`	`bool`	Enable copy centroid
`copysampleindex`	`uint8_t`	Copy sample index
`copydepthtocolorenable`	`bool`	Enable depth-to-color copy
`copystenciltocolorenable`	`bool`	Enable stencil-to-color copy

GnmDepthStencilControl¶

Controls depth and stencil testing state.

typedef struct {
    bool zwrite;
    GnmDepthCompare zfunc;
    GnmDepthCompare stencilfunc;
    GnmDepthCompare stencilbackfunc;
    bool separatestencilenable;
    bool depthenable;
    bool stencilenable;
    bool depthboundsenable;
} GnmDepthStencilControl;

Field	Type	Description
`zwrite`	`bool`	Enable depth writes
`zfunc`	`GnmDepthCompare`	Depth comparison function
`stencilfunc`	`GnmDepthCompare`	Front-face stencil comparison function
`stencilbackfunc`	`GnmDepthCompare`	Back-face stencil comparison function
`separatestencilenable`	`bool`	Enable separate front/back stencil
`depthenable`	`bool`	Enable depth testing
`stencilenable`	`bool`	Enable stencil testing
`depthboundsenable`	`bool`	Enable depth bounds testing

GnmPrimitiveSetup¶

Controls primitive setup state including culling, fill mode, and provoking vertex.

typedef struct {
    GnmCullMode cullmode;
    GnmFaceOrientation frontface;
    GnmFillMode frontmode;
    GnmFillMode backmode;
    bool frontoffsetmode;
    bool backoffsetmode;
    bool vertexwindowoffsetenable;
    GnmProvokingVertex provokemode;
    bool perspectivecorrectiondisable;
} GnmPrimitiveSetup;

Field	Type	Description
`cullmode`	`GnmCullMode`	Culling mode (none/front/back/both)
`frontface`	`GnmFaceOrientation`	Front-face winding orientation
`frontmode`	`GnmFillMode`	Front-face fill mode
`backmode`	`GnmFillMode`	Back-face fill mode
`frontoffsetmode`	`bool`	Front-face offset mode
`backoffsetmode`	`bool`	Back-face offset mode
`vertexwindowoffsetenable`	`bool`	Enable vertex window offset
`provokemode`	`GnmProvokingVertex`	Provoking vertex mode
`perspectivecorrectiondisable`	`bool`	Disable perspective correction

GnmViewportTransformControl¶

Controls which components of the viewport transform are applied.

typedef struct {
    bool scalex;
    bool offsetx;
    bool scaley;
    bool offsety;
    bool scalez;
    bool offsetz;
    bool perspectivedividexy;
    bool perspectivedividez;
    bool invertw;
} GnmViewportTransformControl;

Field	Type	Description
`scalex`	`bool`	Apply X scale
`offsetx`	`bool`	Apply X offset
`scaley`	`bool`	Apply Y scale
`offsety`	`bool`	Apply Y offset
`scalez`	`bool`	Apply Z scale
`offsetz`	`bool`	Apply Z offset
`perspectivedividexy`	`bool`	Apply perspective divide on X/Y
`perspectivedividez`	`bool`	Apply perspective divide on Z
`invertw`	`bool`	Invert W coordinate