6.3 Function specifications

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List

Title Function specifications

Function VDP1 3D work area definition macro

Function Name SPR_3DefineWork

No 1

Form

[# define SPR_3USE_DOUBLE_BUF]

[# define SPR_3NEED_WORLD_VERT]

#include "sega_spr.h"

SPR_3DefineWork (WORK3D, OBJ_SURF_MAX, OBJ_VERT_MAX)

input

WORK3D	: Work area name
OBJ_SURF_MAX	: Maximum number of objects
OBJ_VERT_MAX	: Maximum number of vertices of object

function

Define the work area used for VDP1 3D display in the data area in the AP.
# define SPR_3USE_DOUBLE_BUF can be omitted, and if specified, processing such as coordinate conversion by DSP and SH processing will be parallelized using two object vertex coordinates and surface brightness tables to increase execution speed.
# define SPR_3NEED_WORLD_VERT is optional, and if specified, the vertex coordinate table in the world coordinate system will be notified when the coordinate conversion result is notified.
# define SPR_3USE_DOUBLE_BUF and # define PR_3NEED_WORD_VERTH must be defined before #define "sega_spr.h" is defined.

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List

Title Function specifications

Function Initialization of VDP1 3D display

Function Name SPR_3Initial

No 2

Form

void SPR_3Initial (Spr3WorkArea * workArea)

input

workArea: Work area definition table

output

none

Function value

none

function

Initializes the VDP1 3D display.

• The viewpoint is the origin of the world coordinate system, the viewpoint angle is (0,0,0) (positive direction of Z), and the rotation operation is set in the order of X → Y → Z.
• The light source angle is (0,0,0) (positive direction of Z).
• The clipping level is 2, and the maximum / minimum display range of the Z coordinate of the viewpoint coordinate system is from -0.005 to the minimum negative value.

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List

Title Function specifications

Function Set of clipping modes

Function Name SPR_3SetClipLevel

No 3

Form

void SPR_3SetClipLevel (Uint16 clipLevel, Fixed32 clipZmin, Fixed32 clipZmax)

input

clipLevel: Clipping level number

number	meaning
0	No clipping.
1	In the Z range of the viewpoint coordinate system, the Z value of the representative point of the clip polygon outside the specified Z value range is not drawn.
2 or more	Clip in a field-of-view pyramid with the entire framebuffer as the screen. Polygons outside the field of view pyramid are not drawn even at one point.

clipZmin: viewpoint coordinate system Z coordinate clip minimum value

clipZmax: Viewpoint coordinate system Z coordinate clip maximum value

output

none

Function value

none

function

Sets the clipping level of the polygon. The upper level includes the functions of the lower level. For level 1, clipping is done in the viewpoint coordinate system with the maximum Z coordinate value of the polygon, but the range must be set with clipZmin and clipZmax before executing SPR3_DrawModel ().

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List

Title Function specifications

Function Set of pixel counts

Function Name SPR_3SetPixelCount

No Four

Form

void SPR_3SetPixelCount (Uint16 pixelCountX, Uint16 pixelCountY)

input

pixelCountX	: Number of pixels per unit of Clean X
pixelCountY	: Number of pixels per unit of screen Y

output

none

Function value

none

function

Sets the number of screen pixels for each 1.0 of XY during fluoroscopic conversion to the screen. At the time of initial setting, each is set to 256.

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List

Title Function specifications

Function Light source set

Function Name SPR_3SetLight

No Five

Form

void SPR_3SetLight (Uint16 moveKind, MthXyz * lightAngle)

input

moveKind	: Type of movement amount
b0	: 0 = Relative movement
	1 = Absolute move
b1	: 0 = Rotational movement is angle
	1 = Rotational movement is a unit vector
lightAngle	: When the rotational movement amount of the parallel light source is an angle, the specified range of the movement amount is as follows.
	If a vector is specified, it will be converted to an angle.
	FIXED (-180.0) ≤ Rotational movement amount ≤ FIXED (180.0)
	The rotation operation is performed in the order of X → Y → Z.

output

none

Function value

none

function

Set the light source angle.

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List

Title Function specifications

Function Set of viewpoints

Function Name SPR_3SetView

No 6

Form

voidSPR_3SetView (Uint16 moveKind, MthXyz * viewPoint, MthXyz * viewAngle, Uint16 angleSeq, MthXyz * viewCoordPoint)

input

moveKind	: Type of movement amount
b0	: 0 = Relative movement
	1 = Absolute move
b1	: 0 = Rotational movement is angle
	1 = Rotational movement is a vector
viewPoin	: Viewpoint position or translation amount.
	If the rotation position of the viewpoint in the world coordinate system is 0, it will be ignored.
viewAngle	: When the rotation movement amount of the viewpoint is an angle, the specified range of the movement amount is as follows.
	If a vector is specified, it will be converted to an angle.
	FIXED (-180.0) ≤ Rotational movement amount ≤ FIXED (180.0)
	If it is 0, it will be ignored.
angleSeq	: Viewpoint rotation operation
viewCoordPoint	: Viewpoint position or translation amount in the viewpoint coordinate system.
	If it is 0, it will be ignored. The initial value is (0,0,0).

output

none

Function value

none

function

Moves the viewpoint position within the world coordinate system and rotates around that position.
If viewCoordPoint is specified, the viewpoint position is moved from the origin to the specified position in the viewpoint coordinate system.

angleSeq = ROT_SEQ_ZYX: Rotate the viewpoint in the order of Z → Y → X = ROT_SEQ_ZXY: ”Z → X → Y”
         = ROT_SEQ_YZX: "Y → Z → X"
         = ROT_SEQ_YXZ: "Y → X → Z"
         = ROT_SEQ_XYZ: "X-> Y-> Z"
         = ROT_SEQ_XZY: "X-> Z-> Y"

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List

Title Function specifications

Function Cluster movement

Function Name SPR_3MoveCluster

No 7

Form

void SPR_3MoveCluster (SprCluster * cluster, Uint16 moveKind, MthXyz * angle, MthXyz * point)

input

cluster	: Pointer of cluster table to move
moveKind	: Type of movement amount
b0	: 0 = Relative movement
	1 = Absolute move
b1	: 0 = Rotational movement is angle
	1 = Rotational movement is a unit vector
angle	: When the rotational movement amount is an angle, the specified range of the movement amount is as follows.
	If a vector is specified, it will be converted to an angle.
	FIXED (-180.0) ≤ Rotational movement amount ≤ FIXED (180.0)
point	: Translation amount

output

none

Function value

none

function

Move the cluster in the order of rotation and translation.
If angle and point are 0 respectively, the values are ignored.

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List

Title Function specifications

Function Model registration

Function Name SPR_3DrawModel

No 8

Form

void SPR_3DrawModel (SprCluster * rootCluster)

input

rootCluster: Pointer to the root cluster table of the model to display

output

none

Function value

none

function

Register the model.

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List

Title Function specifications

Function Model drawing

Function Name SPR_3Flush

No 9

Form

void SPR_3Flush (void)

input

none

output

none

Function value

none

function

Draw the model.
SPR_3 Completes Z sorting in the viewpoint coordinate system of the polygon group registered by DrawMode ().

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List

Title Function specifications

Function Set of textures

Function Name SPR_3SetTexture

No Ten

Form

void SPR_3SetTexture (SprTexture * texture)

input

texture: Texture table pointer

output

none

Function value

none

function

Set the texture.

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List

Title Function specifications

Function Release texture area

Function Name SPR_3ClrTexture

No 11

Form

void SPR_3ClrTexture (SprTexture * texture)

input

texture: Texture table pointer

output

none

Function value

none

function

Free the texture area.

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List

Title Function specifications

Function Function call to all clusters

Function Name SPR_3CallAllCluster

No 12

Form

void SPR_3CallAllCluste (SprCluster * cluster, void (* userFunc) (SprCluster *))

input

cluster	: Root cluster table pointer
userFunc	: User function

output

none

Function value

none

function

Call the specified function with the class table as a parameter for each cluster connected to the root cluster.

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List

Title Function specifications

Function Change texture color data

Function Name SPR_3ChangeTexColor

No 13

Form

voidSPR_3ChangeTexColor (Uint16 charNo, Uint16 color, SprLookupTbl * lookupTbl)

input

charNo

: Character number

color

: Color data lookup table number or color bank code

lookupTbl

: Look-up table pointer

output

none

Function value

none

function

Changes the color data and color lookup table of the registered texture specified by the character number. If lookupTbl is 0, only the color is changed and the color lookup table is not registered.

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List

Title Function specifications

Function Set the minimum and maximum values of the Z sort range

Function Name SPR_3SetZSortMinMax

No 14

Form

voidSPR_3SetZSortMinMaxl (Uint16 zSortMode, Fixed32 zSortMin, Fixed32 zSortMax)

input

zSortMode	: Z sort Z coordinate value adoption mode
	ZSORT_FLOAT_MODE = Floating mode
	ZSORT_FIXED_MODE = Fixed mode
zSortMin	: Viewpoint coordinate system Z sort Z coordinate minimum value
zSortMax	: Viewpoint coordinate system Z sort Z coordinate maximum value

output

none

Function value

none

function

zSortMin and zSortMax are parameters that specify the range of Z that divides the drawing order into blocks, and are set before executing the SPR3_DrawModel () routine.
The initial values are zSortMin and zSortMax, which are specified when the floating mode is specified as the Z coordinate value adoption mode, and the Z coordinate maximum and minimum values of the viewpoint coordinate system at the time of the previous drawing are adopted for the subsequent Z range.
In fixed mode, the specified zSortMin and zSortMax are adopted as fixed values.
At the time of initial setting of the SPR_3Initial () routine, -10.0 is set as zSortMin and 0.0 is set as zSortMax, and the Z coordinate value adoption mode is floating mode.
In the viewpoint coordinate system, the viewpoint position coordinates are 0.0 and point in the minus direction of Z.
The blocks used in Z sort use the drawing priority blocks of VDP1 extension processing, so if you want to perform Z sorting finely, you need to take a large number of drawing priority blocks in the 2D work area definition.
Also, if you want to do Z sort, you must set drawPrtyFlag = SPR_2DRAW_PRTY_ON in the SPR_2OpenCommand () routine.

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List

Title Function specifications

Function Acquisition of current 3D environment data

Function Name SPR_3GetStatus

No 15

Form

void SPR_3GetStatus (Spr3dStatus * spr3dStatus)

input

none

output

spr3dStatus: Pointer for 3D environment data table

Function value

none

function

Acquires the current 3D environment data.

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List

Title Function specifications

Function Object surface normal vector calculation

Function Name SPR_3SetSurfNormVect

No 16

Form

void SPR_3SetSurfNormVect (SprObject3D * obj)

input

none

output

obj: 3D object

Function value

none

function

Calculates the normal vector from the face vertex table of the specified 3D object and sets it in the face normal vector table. The normal vector is perpendicular to the face vertex order clockwise.
You need to set the surfNormK parameter for the 3D object.

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List

Title Function specifications

Function VDP1 fast drawing parameter set

Function Name SPR_3SetDrawSpeed

No 17

Form

voidSPR_3SetDrawSpeed (Sint32 hssFlag, Sint32 eosFlag, Sint32 pclpFlag)

input

hssFlag	: High speed shrink flag (specify the drawing mode of texture polygon)
	0 = Precision priority drawing (default)
	1 = Speed priority drawing
eosFlag	: Sampling coordinates of the original texture when speed priority drawing is specified
	0 = Sampling even coordinates (default)
	1 = Sampling odd coordinates
pclpFlag	: Pre-clipping enable / disable flag
	0 = Enabled (default)
	1 = invalid

output

none

Function value

none

function

Set the high-speed drawing mode to be embedded in the drawing mode of the VDP1 sprite command. Please refer to the VDP1 hardware manual for high-speed shrink and pre-clipping.

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★ PROGRAMMER'S GUIDE ★ VDP1 library

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Copyright SEGA ENTERPRISES, LTD., 1997