TftBmpFromCode()

Library Description ›› System ››
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Syntax

TftBmpFromCode(dwBmpAlias As dwTftLibParameter1, wOriginX As wTftLibParameter1, wOriginY As wTftLibParameter2, bTransparent As bTftLibParameter1, wAlphaColor As wTftLibParameter3, bInvert As bTftLibParameter2, bOverlay As bTftLibParameter3)

Overview

Description:

Prints a BMP image stored in program (flash) memory to the TFT screen, with optional image processing effects.

Parameters

Parameter

Description

dwBmpAlias

Alias name of the BMP image table stored in flash memory

wOriginX

X-coordinate of the bottom-left corner on the screen where the image will be drawn

wOriginY

Y-coordinate of the bottom-left corner on the screen where the image will be drawn

bTransparent

Transparency mode:
0 = Normal rendering (no transparency)
1 = Transparent rendering (skip pixels matching the alpha color)

wAlphaColor

Alpha color value used when transparency is enabled

bInvert

Color inversion mode:
0 = Normal colors
1 = Invert image colors

bOverlay

Pixel overlay (blending) effect:
0 = NONE - No overlay; direct pixel replacement
1 = OR - Lightens overlapping areas (bitwise OR); merges bright regions
2 = AND - Keeps only common bits; intersection-style effect
3 = XOR - Highlights differences; toggles pixels where colors differ
4 = NAND - Inverts the intersection; brightens overlap zones
5 = NOR - Inverts the union; produces darker overlays
6 = XNOR - Preserves pixels where both values match; strong masking effect
7 = ADD - Adds color values; brightens overlapping regions (light addition)
8 = SUB - Subtracts color values; darkens overlapping regions (shadow-like effect)
9 = AVG - Averages source and destination colors; soft blending effect
10 = SCR - Screen blend (inverse multiply); brightens highlights
11 = MUL - Multiply blend; darkens overlapping areas (similar to Photoshop “Multiply”)
12 = CON - Contrast blend; enhances midtones using a non-linear mix

Notes

Processing order is: transparency check → color inversion → overlay → final pixel output.

Transparent rendering is slower because each pixel must be evaluated individually, rather than using block-based transfers.

Overlay effects further reduce performance, as they require reading, modifying,and writing each destination pixel.

If the global "TftPixelCheck" flag is enabled, boundary checks are performed:

If the image lies completely outside the visible screen area, it will not be drawn.

If the image is partially outside the visible area, it will be clipped to the screen boundaries before rendering.

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