fill.h File Reference

Detailed Description

Design Philosophy

Fill algorithms are used to fill bounded spaces on the display with a given color. Fill algorithms can be computationally expensive, so a variety are provided to best suit your need.

Usage

fillDisplayArea() is used to fill a rectangular area. It does not care about what is on the display prior.

shadeDisplayArea() is used to shade a rectangular area using

oddEvenFill() is an efficient way to fill areas using the Even–odd rule. It may not work in all cases, but if it does work, it is preferrable to use.

floodFill() is a less efficient way to fill areas using the Flood fill recursive algorithm. It produces better results than oddEvenFill(), but is considerably slower and uses far more stack memory.

Example

// Fill the display area with a dark cyan
fillDisplayArea(0, 0, TFT_WIDTH, TFT_HEIGHT, c123);
 
// Shade different areas with different intensities, medium brown
for (int i = 0; i < 5; i++)
{
    shadeDisplayArea(0, (i * TFT_HEIGHT) / 5, TFT_WIDTH / 2, ((i + 1) * TFT_HEIGHT) / 5, i, c321);
}
 
// Draw a red circle
drawCircle(200, 50, 20, c500, 0, 0, 1, 1);
// Flood fill the circle with blue
floodFill(200, 50, c005, 200 - 20, 50 - 20, 200 + 50, 50 + 20);
 
// Draw a green rectangle
drawRect(200, 150, 250, 220, c050, 0, 0, 1, 1);
// Odd-even fill the rectangle with blue
oddEvenFill(190, 140, 260, 230, c050, c005);

Go to the source code of this file.

Functions
void	fillDisplayArea (int16_t x1, int16_t y1, int16_t x2, int16_t y2, paletteColor_t c)
	Fill a rectangular area on a display with a single color.
void	shadeDisplayArea (int16_t x1, int16_t y1, int16_t x2, int16_t y2, uint8_t shadeLevel, paletteColor_t color)
void	oddEvenFill (int x0, int y0, int x1, int y1, paletteColor_t boundaryColor, paletteColor_t fillColor)
	Attempt to fill a convex shape bounded by a border of a given color using the even-odd rule.
void	floodFill (uint16_t x, uint16_t y, paletteColor_t col, uint16_t xMin, uint16_t yMin, uint16_t xMax, uint16_t yMax)
void	fillCircleSector (uint16_t x, uint16_t y, uint16_t innerR, uint16_t outerR, uint16_t startAngle, uint16_t endAngle, paletteColor_t col)
	Helper function to draw a filled circle with translation and scaling.

Function Documentation

fillDisplayArea()

void fillDisplayArea	(	int16_t	x1,
		int16_t	y1,
		int16_t	x2,
		int16_t	y2,
		paletteColor_t	c )

Fill a rectangular area on a display with a single color.

Parameters

x1	The x coordinate to start the fill (top left)
y1	The y coordinate to start the fill (top left)
x2	The x coordinate to stop the fill (bottom right)
y2	The y coordinate to stop the fill (bottom right)
c	The color to fill

shadeDisplayArea()

void shadeDisplayArea	(	int16_t	x1,
		int16_t	y1,
		int16_t	x2,
		int16_t	y2,
		uint8_t	shadeLevel,
		paletteColor_t	color )

'Shade' an area by drawing pixels over it in a ordered-dithering way

Parameters

x1	The X pixel to start at
y1	The Y pixel to start at
x2	The X pixel to end at
y2	The Y pixel to end at
shadeLevel	The level of shading, Higher means more shaded. Must be 0 to 4
color	the color to draw with

oddEvenFill()

void oddEvenFill	(	int	x0,
		int	y0,
		int	x1,
		int	y1,
		paletteColor_t	boundaryColor,
		paletteColor_t	fillColor )

Attempt to fill a convex shape bounded by a border of a given color using the even-odd rule.

https://en.wikipedia.org/wiki/Even%E2%80%93odd_rule

WARNING!!! This is very finicky and is not guaranteed to work in all cases.

This iterates over each row in the bounding box, top to bottom, left to right

This assumes that each row starts outside or on the boundary of the shape to be filled.

Each time a pixel of the 'boundary color' is iterated over, the in/out boolean will flip. Thick boundaries will have hysteresis, but shapes with concave features will have undrawn rows because the function checks for an even number of transitions within a row before drawing.

Parameters

x0	The left index of the bounding box
y0	The top index of the bounding box
x1	The right index of the bounding box
y1	The bottom index of the bounding box
boundaryColor	The color of the boundary to fill in
fillColor	The color to fill

floodFill()

void floodFill	(	uint16_t	x,
		uint16_t	y,
		paletteColor_t	col,
		uint16_t	xMin,
		uint16_t	yMin,
		uint16_t	xMax,
		uint16_t	yMax )

This is a recursive flood fill algorithm. It starts at the given coordinate, and will replace the color at that coordinate, and all adjacent pixels with the same color, with the fill color.

The flood is also bounded wthin the given rectangle.

Note that the recursive algorithm is relatively slow and uses a lot of stack memory, so try not to use it when possible.

This is adapted from http://www.adammil.net/blog/v126_A_More_Efficient_Flood_Fill.html

Parameters

x	The X coordinate to start the fill at
y	The Y coordinate to start the fill at
col	The color to fill in
xMin	The minimum X coordinate to bound the fill
yMin	The minimum Y coordinate to bound the fill
xMax	The maximum X coordinate to bound the fill
yMax	The maximum Y coordinate to bound the fill

fillCircleSector()

void fillCircleSector	(	uint16_t	x,
		uint16_t	y,
		uint16_t	innerR,
		uint16_t	outerR,
		uint16_t	startAngle,
		uint16_t	endAngle,
		paletteColor_t	col )

Helper function to draw a filled circle with translation and scaling.

Parameters

x	The X coordinate of the center of the circle
y	The Y coordinate of the center of the circle
innerR	The radius of the inside of the sector, or 0 for the whole circle
outerR	The radius of the circle
startAngle	The starting angle of the sector, in degrees CCW
endAngle	The ending angle of the sector, in degrees CCW
col	The color to fill