Convert more floats to ints

[laurentlb]

There are more cases where we could replace a float with an int (1 instead of 1.).

See discussion in https://www.pouet.net/topic.php?which=12089&page=1

Quote from the spec:

The OpenGL Shading Language is type safe. There are no implicit conversions between types, with the exception that an integer value may appear where a floating-point type is expected, and be converted to a floating-point value. Exactly how and when this can occur is described in section 4.1.10 “Implicit Conversions” and as referenced by other sections in this specification.