CUDA Syntax overview.

[Robadob]

Simple page/section aimed at Python users explaining the CUDA C equivalent of common syntax vs python which they may need for defining agent functions.

E.g, defining variable, if-else, for, function define/call.

Could link to an external guide/s at the end for greater detail.

[Robadob]

Agent Function/CUDA Syntax

FLAMGPU agent functions are written using CUDA, which itself is a form of C++ (albeit lacking support for most of the standard library). The syntax required to write agent functions is likely to be cover a small subset of available C++ feature, common to other C style languages such as Java and C# like control flow operations, rather than needing to learn about technical features such as manual memory management and pointers.

If you're using the Python API and are unfamiliar with these languages, the difference between common statements is outlined below:

Variables

Python

foo = 5
foo += 2
bar = foo

CUDA

int foo = 5;
foo += 2;
int bar = foo;

Unlike python, CUDA requires variables types to be specified. The types supported by FLAMEGPU are:

Signed Integer	Unsigned Integer	Floating Point
int / int32_t	unsigned int / uint32_t	float
long long / int64_t	unsigned long long / int64_t	double
signed char / int8_t	unsigned char / int8_t
short / int16_t	unsigned short / int16_t

if-else statements

Python

if foo == 1:
    bar = 5
elif foo == 2:
    bar = 6
else:
    foo = 1
    bar = 7

CUDA

int bar;
if (foo == 1) {
    bar = 5;
} else if (foo == 2) {
    bar = 6;
} else {
    foo = 1;
    bar = 7;
}

CUDA uses curly brackets instead of indentation for scoping blocks. (The brackets aren't strictly required if there's only a single statement (;) in the block.

for loops

Python

for i in range(10):
  # do something

CUDA

for (int i = 0; i < 10; ++i) {
  // do something
}

For loops have 3 parts, separated by semi colons; for(<variable definition>;<condition>;<post-iteration action>).

etc..