55
\$\begingroup\$

In a GLSL fragment shader I am trying to cast a float into an int. The compiler raises an error:

ERROR: 0:60: '=' : cannot convert from 'mediump float' to 'highp int'

I tried raising the precision of the int:

mediump float indexf = floor(2.0 * mixer); highp int index = indexf;

but to no avail.

How do I cast the int properly?

\$\endgroup\$
3
  • 1
    \$\begingroup\$ For future reference, you will get better answers if you ask general programming questions like this one at Stack Overflow. stackoverflow.com - depending on community feedback this question might be migrated there anyway. \$\endgroup\$ Commented Feb 17, 2011 at 18:48
  • \$\begingroup\$ For reinterpret casts, there are now functions such as floatBitsToInt. \$\endgroup\$ Commented Oct 10, 2014 at 9:35
  • \$\begingroup\$ @jozxyqk In ES, supported since ES 3.0 \$\endgroup\$ Commented Apr 2, 2024 at 0:23

1 Answer 1

Reset to default
56
\$\begingroup\$

Try this:

highp int index = int(indexf);

I found it here.

\$\endgroup\$
7
  • \$\begingroup\$ Also note that casting a float to an int automatically floors it (at least in any implementation I've ever seen) so your call to floor should be unnecessary. \$\endgroup\$ Commented Feb 17, 2011 at 20:03
  • 10
    \$\begingroup\$ In most languages the rounding mode is truncate / round-to-zero, which is equivalent to floor for positive numbers but not negative numbers. I don't remember if this applies to GLSL, but I'd be surprised if it doesn't. \$\endgroup\$ Commented Feb 17, 2011 at 20:19
  • \$\begingroup\$ @Joe That's an interesting fact that I never thought about, and I just confirmed it with a Java test case. \$\endgroup\$ Commented Feb 18, 2011 at 3:05
  • 4
    \$\begingroup\$ Is highp important here? (On an Integer) \$\endgroup\$ Commented Jul 5, 2015 at 6:11
  • 1
    \$\begingroup\$ How cna I convert this to const so that I can sample an array? \$\endgroup\$ Commented Feb 7, 2019 at 20:34

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.