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

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VDP1 User's Manual/Chapter 7 Commands

■7.5 Rectangular sprite drawing command

The rectangle sprite drawing command draws a character pattern to the frame buffer. When drawing, you can flip the character pattern vertically, horizontally, scale, and stretch it at the specified coordinates.
When the end bit is 0B and the command selection bit is 0001B, it is a rectangular sprite drawing command. When the zoom point is 0000B, define by specifying two coordinates. When it is other than 0000B, it is defined as fixed point specification.
Rectangular sprites cannot be rotated 90 degrees. If you want to rotate the sprite by 90 degrees, specify it using the transform sprite drawing command.

●Specify two coordinates (rectangular sprite drawing command)

The contents of the command table for specifying two coordinates are as follows.

bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 CMDCTRL +00 0 JP 0 0 0 0 0 0 Dir 0 0 0 1 CMDLINK +02 LINK specification/8H 0 0 CMDPMOD +04 M.O. 0 0 0 PC Cl Cm Me E.C. SP Color mode color calculation CMDCOLR +06 Color bank, color lookup table/8H (LSB fixed at 00) CMDSRCA +08 Character address/8H CMDSIZE +0A 0 0 Character size X/8 Character size Y/8 CMDXA +0C sign extension Vertex (A), X coordinate (XA) CMDYA +0E sign extension Vertex (A), Y coordinate (YA) +10 +12 CMDXC +14 sign extension Vertex (C), X coordinate (XC) CMDYC +16 sign extension Vertex (C), Y coordinate (YC) +18 +1A CMDGRDA +1C Gouraud shading table/8H 【note】 is ignored (don't care)

The two-point coordinate specification for the rectangular sprite drawing command is defined as follows.

Setting the end bit to 0B and the command selection bit to 0001B makes it a rectangular sprite drawing command. Specify the jump format. When the jump format is Assign or Call, divide the address of the next command table to be processed by 8H and set it to CMDLINK. Set the zoom point to 0000B. Specify 2 coordinates. Set the character pattern read direction. By specifying the reading direction, you can reverse the image vertically or horizontally. If you specify inversion twice by specifying the read direction and specifying the apex (A) (CMDXA, CMDYA) or apex (C) (CMDXC, CMDYC), the inversions will be canceled and the direction will return to the original. . Set up high speed shrink. Specify whether to prioritize accuracy or speed. Set pre-clipping. Specify whether to enable or disable it, considering the clipping area and the drawing position of the part. Specify the user clipping enable bit and clipping mode. Specifies whether user clipping is outside or inside in clipping mode. Set mesh enabled, end code disabled, transparent pixels disabled. Set MSB on for shade or window processing in VDP2. Set the color mode that defines the character pattern. Specifies the color bank when the color mode is color bank mode. When in lookup table mode, divide the color lookup table address by 8H to define. Specify color operation. Color calculation is valid in RGB mode. If you do not want to perform color calculations, specify Replace. When performing Gouraud shading processing, divide the address of the Gouraud shading table by 8H and specify it. Gouraud shading processing is effective for RGB models. Divide the character pattern table address by 8H and define it in CMDSRCA. Define the width and height of the character size defined in the character pattern table in CMDSIZE. The horizontal size is defined as the value divided by 8. Define the upper left coordinates of the drawing area as vertex (A) (CMDXA, CMDYA) and the lower right coordinate as vertex (C) (CMDXC, CMDYC). You can scale, stretch, and draw by specifying the vertex (A) and vertex (C). Also, (XA of vertex (A))＞ (XC of vertex (C)) will result in a horizontally reversed shape. (YA of vertex (A))＞ (YC at vertex (C)) will result in a vertically flipped shape. Note: If vertex A and vertex C are set to the same coordinates, they will be drawn with 1 pixel.

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