PLAYSTATION PRIMITIVE LIST'S MEMBER VARIABLES FORMAT

@PS_2

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Playstation

· 4 years ago

PRIMITIVE LIST'S MEMBER VARIABLES FORMAT

  U_CHAR FLAG           - options for primitive 
 { 
 bit   0;            - LGT. Light source calculation 
                       0 - On.   Light source calculation is carried out 
                       1 - Off.  Light source calculation is not carried out 
 bit   1;            - FCE. Determines if primitive is one or two faced 
                       0 - Primitive has one face 
                       1 - Primitive has two faces 
 bit   2;            - GRD. Determines single or gradient pigment 
                       0 - Primitive has one solid pigment 
                       1 - Primitive has different pigments at each vertex 
 bits  3-7;          - ignored 
 }

  U_CHAR MODE           - options for primitive 
 { 
 bit   0;            - TGE. Brightness calculation at time of calculation 
                       0 - On.   Calculates light 
                       1 - Off.  Draws texture as is (without lighting) 
 bit   1;            - ABE. Activates translucency when rendered 
                       0 - Off.  Primitive is rendered solid. 
                       1 - On.   Primitive is rendered semitranslucent. 
 bit   2;            - TME. Sets whether a texture is used or not 
                       0 - Off.  No texture is rendered. 
                       1 - On.   A texture is rendered. 
 bit   3;            - displays whether a 3 or 4 sided polygon 
                       0 - 3 sided polygon 
                       1 - 4 sided polygon 
 bit   4;            - IIP. Shading mode 
                       0 - Flat shading 
                       1 - Gouraud shading 
 bits  5-7;          - Code. Defines which sort of entity to draw. 
                       0 - Polygon (3 sided or 4 sided) 
                       1 - Straight line 
                       2 - Sprite 
 }

Possible values of ABR (semitransparency method)

Note: Most of these bits are set or cleared according to which type of primitive is being created. Messing around with these may cause unexpected drawing or crashes. The only bit you may want to edit manually is ABE.
For semitransparency to be used when the TMD is rendered, bit 30 of the GsDOBJ's attribute member must be set. To control the semitransparency method, alter the ABR bits of the primitive's TSB member (see below).

 U_SHORT CBA           - position of CLUT in VRAM for primitives with textures 
 { 
 bits  0-5;          - upper 6 bits of 10 bits of X coordinate value 
                       for CLUT in VRAM 
 bits  6-14;         - 9 bits of Y coordinate value for CLUT in VRAM 
 bit 15;             - ignored 
 }

For example -

  u_long  CLUT_X_POS = 640; 
 u_long  CLUT_Y_POS = 480; 
 u_short CBA = (CLUT_X_POS >> 4) + (CLUT_Y_POS << 6);

 U_SHORT TSB           - information about image for primitives with textures 
 { 
 bits  0-4;          - texture page number of texture 
 bits  5-6;          - ABR. Semitransparency method (see below) 
 bits  7-8;          - TPF. Colour mode of the texture (see below) 
 bits  9-15;         - ignored 
 }

Possible values of ABR (semitransparency method)
Note: For semitransparency to be used when the TMD is rendered, bit 30 of the GsDOBJ's attribute member must be set, and the ABE bit of the primitive's mode member must be set (see above).

 0  - 50% background  +50% polygon 
1  - 100% background +100% polygon 
2  - 100% background - 100% polygon 
3  - 100% background + 25% polygon

Possible values of TPF (colour mode)

 0  - 4 bit texture and CLUT 
1  - 8 bit texture and CLUT 
2  - 15 bit texture with no CLUT

For example -

  u_long  IMG_X_POS = 640; 
 u_long  IMG_Y_POS = 0; 
 u_long  ABR = 1;  // 100% back + 100% polygon 
 u_long  TPF = 0;  // 16 colour texture 
 u_short TXT_TPAGE; 
 TXT_TPAGE = GetTPage((int) TPF, (int) ABR, IMG_X_POS, IMG_Y_POS); 
 u_short TSB = (TXT_TPAGE) + (ABR << 5) + (TPF << 7);