https://gradient-blaster.grahambates.com
Gradient Blaster is a web-based tool to build gradient data for retro platforms using a visual editor. It supports multiple algorithms for colour blending and dithering. The gradient data can be exported in several formats for use with different languages and use cases.
The number of values in the gradient output i.e. the number of pixels it spans.
The colour model / algorithm used to interpolate between points in the gradient.
The platform and colour mode that the gradient is intended for:
Platform | Bit depth | Data format |
---|---|---|
Amiga OCS/ECS | 12 bit (4 per channel) | Single word:R3 R2 R1 R0 G3 G2 G1 G0 B3 B2 B1 B0 |
Amiga OCS/ECS Interlaced |
15 bit (effective) | As above, but two alternating frames to give the appearence of blended colours and provide an extra 'fake' bit per channel |
Amiga AGA | 24 bit (8 per channel) | Two words: high/low nibbles A: R7 R6 R5 R4 G7 G6 G5 G4 B7 B6 B5 B4 B: R3 R2 R1 R0 G3 G2 G1 G0 B3 B2 B1 B0 |
Atari ST | 9 bit (3 per channel) | Single word:__ R2 R1 R0 __ G2 G1 G0 __ B2 B1 B0 |
Atari STe/TT | 12 bit (4 per channel) | Single word: LSB firstR0 R3 R2 R1 G0 G3 G2 G1 B0 B3 B2 B1 |
Atari Falcon | 18 bit (6 per channel) | Single longword: 2 LSB per byte unused, 3rd byte blankR5 R4 R3 R2 R1 R0 __ __ G5 G4 G3 G2 G1 G0 __ __ __ __ __ __ __ __ __ __ B5 B4 B3 B2 B1 B0 __ __ |
Atari Falcon true colour |
16 bit (5 red, 6 green, 5 blue) | Single word:R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 |
Multiplier for noise or adjustments applied by the current dithering algorithm.
Maximum numer of pairs to swap at each boundary when using the Shuffle dither mode.
The gradient is defined by a list of fixed points which have a colour value and position. These are then interpolated to provide the intermediate values.
The left hand panel (2) shows the currently selected point and allows you to edit the colour and position. The center panel shows a preview of the gradient (4) and has markers for the points in the track down the left hand side (3).
Click in the track (3) to add a new point at that position
To change to the position of a point you can either:
To remove a point for the gradient can either:
The gradient can be exported in the following formats:
For Amiga targets, outputs data for the Copper to output the vertical gradient based on line wait commands.
Outputs the raw colour values for each step in the gradient. Supports code generation for several languages, as well as binary download in Big Endian suitable for INCBIN
into your code.
Download a PNG of the gradient preview. This contains the vertical gradient as shown in the preview, but at native resolution and allows you to specify the width. This can then be shared with designers/graphicians.