OS_SpriteOp 56 (changes)

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Programmer's OS Reference SWI Manuals Calls

» Part OS_SpriteOp 15 – SWI Calls

» OS_SpriteOp 56 – Plot Sprite TransformedOS

OS_SpriteOp 56 – Plot Sprite Transformed

(SWI &2E)

Use

This call paints a transformed sprite to the screen. When supplied with the right translation table, it is able to paint a sprite created in any source mode to any destination mode. If a translation table is not supplied when one is required, an error will be generated. Therefore when plotting arbitrary sprites it is recommended to always call ColourTrans_SelectTable or ColourTrans_GenerateTable before the plot in order to generate a suitable table.

If R3 bit 0 is clear, R6 is treated as a pointer to a Draw module Transformation Matrix describing the transform to apply to the sprite. If bit 0 is set then R6 is treated as a pointer to a block giving the screen coordinates of a parallelogram to transform the sprite into:

If R3 bit 1 is set then R4 is treated as a pointer to a coordinate block specifying a subrectangle of the sprite to render from, with coordinates given in pixels:

When specifying a destination parallelogram, the source rectangle is mapped onto the destination as follows:

x0,y0 -> X0,Y0
x1,y0 -> X1,Y1
x1,y1 -> X2,Y2
x0,y1 -> X3,Y3

Notes

See OS_SpriteOp Scaled/Transformed Plot Flags for details on how the flags affect the plot operation and dictate some of the input parameters.

See also

• Format Of Sprite
• Format Of Sprite Area
• OS_SpriteOp
• OS_SpriteOp Scaled/Transformed Plot Flags
• ColourTrans_SelectTable
• ColourTrans_GenerateTable
• Colour Mapping Descriptor
• Transformation Matrix