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★ HARDWARE Manual ★ VDP1 User's Manual ★ Chapter 7 Commands

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VDP1 User's Manual / Chapter 7 Commands

● Fixed point specification (rectangular sprite drawing command)

The contents of the command table for specifying fixed points are as follows.

bit 15 14 13 12 11 Ten 9 8 7 6 5 4 3 2 1 0 CMDCTRL +00 0 JP ZP 0 0 Dir 0 0 0 1 CMDLINK +02 LINK designation / 8H 0 0 CMDPMOD +04 MO 0 0 0 Pc Cl Cm Me EC SP Color mode Color calculation CMDCOLR +06 Color bank, color look-up table / 8H (LSB fixed to 00) CMDSRCA +08 Character address / 8H CMDSIZE + 0A 0 0 Character size X / 8 Character size Y / 8 CMDXA + 0C Sign extension Fixed point (A), X coordinate (XA) CMDYA + 0E Sign extension Fixed point (A), Y coordinate (YA) CMDXB +10 Sign extension Vertex (B), X coordinate (XB) CMDYB +12 Sign extension Vertex (B), Y coordinate (YB) +14 +16 +18 + 1A CMDGRDA + 1C Gouraud shading table / 8H 【note】 Is ignored (don't care)

The fixed point specification of the rectangular sprite drawing command is defined as follows.

Setting the end bit to 0B and the command selection bit to 0001B results in a rectangular sprite drawing command.
Specify the jump format. When the jump format is assign or call, divide the address of the command table to be processed next by 8H and set it to CMDLINK.
Set the zoom point. If the zoom point (fixed point) is set to a value other than 0000B, the fixed point will be specified. If 0000B is set, two coordinates will be specified.
For more information on zoom points, see the " Zoom Points " section in Chapter 6, Command Tables.
Set the reading direction of the character pattern. You can draw by flipping vertically or horizontally by specifying the reading direction.
Set high speed shrink. Specify precision priority or speed priority.
Set pre-clipping. Consider the clipping area and the drawing position of the part, and specify whether it is enabled or disabled.
Specifies the user clipping enabled bit and the clipping mode. Specifies whether user clipping is outside or inside in clipping mode.
Set mesh enabled, end code disabled, and transparent pixel disabled. Sets the MSB on for shading or windowing in VDP2.
Sets the color mode that defines the character pattern. Specify the color bank when the color mode is color bank mode. In lookup table mode, define the color lookup table address by dividing it by 8H.
Specifies the color operation. Color calculation is valid in RGB mode. If you do not want to perform color calculation, specify replacement. When performing Gouraud shading processing, specify the address of the Gouraud shading table by dividing it by 8H. Gouraud shading processing is effective in RGB mode.
Divide the address of the character pattern table by 8H and define it in CMDSRCA. Define the horizontal and vertical of the character size defined in the character pattern table in CMDSIZE. The horizontal size defines the value divided by 8.
Set the fixed point coordinates of the character to be drawn to the fixed point coordinates (CMDXA, CMDYA). Define the display width in CMDXB and CMDYB. You can enlarge / reduce or expand / contract the drawing by specifying the display width.
Note: If you set the CMDXB and CMDYB values to (0,0), it will be drawn in 1 pixel.

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★ HARDWARE Manual ★ VDP1 User's Manual