ImpellerColorMatrix Struct Reference

#include <impeller.h>

Public Attributes
float	m [20]

Detailed Description

A 4x5 matrix using row-major storage used for transforming color values.

To transform color values, a 5x5 matrix is constructed with the 5th row being identity. Then the following transformation is performed:

| R' |   | m[0]  m[1]  m[2]  m[3]  m[4]  |   | R |
| G' |   | m[5]  m[6]  m[7]  m[8]  m[9]  |   | G |
| B' | = | m[10] m[11] m[12] m[13] m[14] | * | B |
| A' |   | m[15] m[16] m[17] m[18] m[19] |   | A |
| 1  |   | 0     0     0     0     1     |   | 1 |

The translation column (m[4], m[9], m[14], m[19]) must be specified in non-normalized 8-bit unsigned integer space (0 to 255). Values outside this range will produce undefined results.

The identity transformation is thus:

1, 0, 0, 0, 0,
0, 1, 0, 0, 0,
0, 0, 1, 0, 0,
0, 0, 0, 1, 0,

Some examples:

To invert all colors:

-1,  0,  0, 0, 255,
 0, -1,  0, 0, 255,
 0,  0, -1, 0, 255,
 0,  0,  0, 1,   0,

To apply a sepia filter:

0.393, 0.769, 0.189, 0, 0,
0.349, 0.686, 0.168, 0, 0,
0.272, 0.534, 0.131, 0, 0,
0,     0,     0,     1, 0,

To apply a grayscale conversion filter:

0.2126, 0.7152, 0.0722, 0, 0,
0.2126, 0.7152, 0.0722, 0, 0,
0.2126, 0.7152, 0.0722, 0, 0,
0,      0,      0,      1, 0,

See also

ImpellerColorFilter

Definition at line 601 of file impeller.h.

Member Data Documentation

m

float ImpellerColorMatrix::m[20]

Definition at line 602 of file impeller.h.

Referenced by impeller::interop::ImpellerColorFilterCreateColorMatrixNew().

---

The documentation for this struct was generated from the following file:

• impeller/toolkit/interop/impeller.h