TftBmpFromCodeRotate()

Library Description ›› System ››
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Syntax

TftBmpFromCodeRotate(dwBmp As dwTftLibParameter1, wX_Pos As wTftLibParameter2, wY_Pos As wTftLibParameter3, wAngleDeg As wTftLibParameter4, wBackground As wTftLibParameter5, bTransparent As bTftLibParameter1, wAlphaColor As wTftLibParameter6, bInvert As bTftLibParameter2, bOverlay As bTftLibParameter3), Byte

Overview

Renders a BMP image stored in program (FLASH) memory, rotates it counter-clockwise by a specified angle, and applies optional transparency, color inversion, and pixel-overlay effects.

Parameters

Parameter

Description

dwBmp

Symbolic name of the BMP image table stored in program memory.

wX_Pos

X-coordinate of the rotated image’s lower-left corner.

wY_Pos

Y-coordinate of the rotated image’s lower-left corner.

wAngleDeg

Rotation angle in degrees (CCW).

wBackground

Fill color for empty areas introduced by rotation.

bTransparent

Transparency mode:
0 – Normal rendering (no transparency)
1 – Skip pixels matching the alpha-key color

wAlphaColor

Alpha-key color used when transparency is enabled.

bInvert

Color inversion:
0 – Normal colors
1 – Invert colors

bOverlay

Pixel overlay/blending mode:
0 = NONE – Direct overwrite
1 = OR – Lightens overlapping areas
2 = AND – Keeps intersecting bits
3 = XOR – Highlights differences
4 = NAND – Inverted AND; bright overlaps
5 = NOR – Inverted OR; darker result
6 = XNOR – Keeps matching pixels
7 = ADD – Adds RGB values; bright blend
8 = SUB – Subtracts RGB values; dark blend
9 = AVG – Averages colors; soft blend
10 = SCR – Screen blend; bright highlights
11 = MUL – Multiply blend; darker result (Photoshop Multiply)
12 = CON – Contrast-enhancing non-linear mix

Return value

Value

Meaning

0

Success

1

Origin outside the visible display area

2

BMP width or height is zero

4

Image partially clipped outside the visible area

Notes

Processing order: transparency → inversion → overlay → render.

Transparency mode is slower because every pixel must be evaluated individually.

Overlay modes are slower due to pixel read-modify-write operations.

When TftPixelCheck is enabled:

Images fully outside the visible area are skipped.

Images partially outside are clipped to display boundaries.

For maximum performance without effects, use TftBmpFromCode().

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