Purpose
Opcode format | Opcode
[ASCII] (Hex) |
Operand Format | Comments |
Extended ASCII | (Texture | [<ws>]<ICount>[<ws><IXi>,<IYi>]+ | Absolute coordinates. |
Single-byte, binary operand | [t] (74) | <BCount>[<USEcount>][<LXi><LYi>]+ | Relative coordinates. |
- | [Ctrl-T] (14) | <BCount>[<USEcount>][<SXi><SYi>]+ | Relative coordinates. |
Extended binrary | TBD | <BCount>[<USEcount>]\
[<LXi><LYi><BRi><BGi><BBi><BAi>]]+ |
Gouraud, relative coordinates. |
- | TBD | <BCount>[<USEcount>]<LIid>\
[<LXi><LYi><LUi><LVi><ULWi>]+ |
Texture mapped, relative coordinates. |
- | TBD | <BCount>[<USEcount>]<LIid>\
[<LXi><LYi><BRi><BGi><BBi><BAi><LUi><LVi><ULWi>]+ |
Gouraud and texture mapped, relative coordinates. |
Ecount When count is zero, a 2-byte extended count follows, allowing for polytriangles with vertices from 256 through 65,791 which are encoded as an integer (0 to 65,535).
Xi,Yi The ith point (in logical coordinates) of the polytriangle.
Iid Selects an image previously defined with Draw Image for use with texture mapping.
Ri, Gi, Bi, Ai The color definition at the ith vertex in the polytriangle.
Ui, Vi, Wi The texture coordinate at the ith vertex in the polytriangle. The coordinate selects colors from the image selected by the Iid parameter.
Figure 1. Example polytriangle with six points
When texture mapping, the Ui and Vi parameters correspond to the horizontal and vertical directions of texture space, and Wi corresponds to the perspective homogeneous coordinate (used when a 2D projection is made from a 3D object). The 32-bit value for Ui and Vi are interpreted as a signed fixed-point texture parameter: the low 16-bits correspond to the normalized fractional portion of the texture image, and the high 16-bits correspond to the integer portion.