gDPSetCombineLERP [Macro]

Function

gDPSetCombineLERP

Sets the color combiner (CC) mode

Syntax

#include <ultra64.h>        /* gbi.h */
gDPSetCombineLERP(
        Gfx  *pkt,
        a0,  b0,  c0,  d0,
        Aa0, Ab0, Ac0, Ad0,
        a1,  b1,  c1,  d1,
        Aa1, Ab1, Ac1, Ad1)
gsDPSetCombineLERP(
        a0,  b0,  c0,  d0,
        Aa0, Ab0, Ac0, Ad0,
        a1,  b1,  c1,  d1,
        Aa1, Ab1, Ac1, Ad1)

Arguments

pkt

Display list pointer

a0, b0, c0, d0

Color input source for 1st cycle

Aa0, Ab0, Ac0, Ad0

Alpha input source for 1st cycle

a1, b1, c1, d1

Color input source for 2nd cycle

Aa1, Ab1, Ac1, Ad1

Alpha input source for 2nd cycle

Returned Value

None.

Description

This macro is used for setting details pertaining to the source input to the RDP's color combiner. Most of the standard input source is set in advance, but by including color constants and alpha constants, you can specify a unique CC mode. gDPSetCombineMode is a simplified version of this macro. Thus, the following two sets of syntax are the same:

(a) gsDPSetCombineMode(G_CC_MODULATE, G_CC_MODULATE)
(b) gsDPSetCombineLERP(TEXEL0, 0, SHADE, 0, TEXEL0, 0,
      SHADE, 0, TEXEL0, 0, SHADE, 0, TEXEL0, 0, SHADE, 0)

For details, see gDPSetCombineMode as well as Section 12.6 "CC: Color Combiner" in the N64 Programming Manual.

Below are the color constants that can be used for the arguments a0, b0, c0, d0 and the arguments a1, b1, c1, d1:

COMBINED

Color combined from 1st cycle

TEXEL0

Texture color

TEXEL1

Texture color from tile+1

PRIMITIVE

Primitive color

SHADE

Shading color

ENVIRONMENT

Environment color

CENTER

Chroma key center value

SCALE

Chroma key scale value

COMBINED_ALPHA

Combined alpha from 1st cycle

TEXEL0_ALPHA

Texture alpha

TEXEL1_ALPHA

Texture alpha from tile+1

PRIMITIVE_ALPHA

Primitive alpha

SHADE_ALPHA

Shading alpha

ENV_ALPHA

Environment alpha

LOD_FRACTION

LOD coefficient

PRIM_LOD_FRAC

Primitive LOD coefficient

NOISE

Random noise

K4

Color conversion constant K4

K5

Color conversion constant K5

1

1.0

0

0.0

Below are the alpha constants that can be used for the arguments Aa0, Ab0, Ac0, Ad0 and the arguments Aa1, Ab1, Ac1, Ad1:

COMBINED

Combined alpha from 1 Cycle mode

TEXEL0

Texture alpha

TEXEL1

Texture alpha from tile+1

PRIMITIVE

Primitive alpha

SHADE

Shading alpha

ENVIRONMENT

Environment alpha

LOD_FRACTION

LOD coefficient

PRIM_LOD_FRAC

Primitive LOD coefficient

1

1.0

0

0.0

See Also

gDPSetCombineMode

Revision History

03/01/99 Newly created.