Pointer Parameters

[cemalgnlts]

Hi,
I am trying to run the graphic library in the browser with emscripten.

I exported this function out:

// Set background color (framebuffer clear color)
void ClearBackground(Color color)
{
    rlClearColor(color.r, color.g, color.b, color.a);
    rlClearScreenBuffers();
}

The structure of the received parameter:

// Color, 4 components, R8G8B8A8 (32bit)
typedef struct Color {
    unsigned char r;
    unsigned char g;
    unsigned char b;
    unsigned char a;
} Color;

This way I can adjust the color:

const ClearBackground = ({ r = 0, g = 0, b = 0, a = 0 }) => {
  const address = rl._malloc(4);
  /*rl.HEAPU8[address] = r;
  rl.HEAPU8[address + 1] = g;
  rl.HEAPU8[address + 2] = b;
  rl.HEAPU8[address + 3] = a;*/

  rl.HEAPU8.set([r, g, b, a], address);
  
  rl._ClearBackground(address);
};

But can't I do it another way? Uint8 in JS or something similar. Also, can the pointer I create with this method be freed by C or do I need to free it with JS?

// Something like:
rl._ClearBackground(new Uint8Array([255, 255, 255, 255]));

[kripken]

If Color is a struct then clang will use an allocated area in memory, so you do need to malloc as you do here (and free, as nothing else knows you allocated it). Another option is to allocate on the stack (stackAlloc) if you know it is small. However, most people change their API to avoid passing structs, and leave only simple types on the boundary, like this:

void ClearBackground(unsigned char r, unsigned char g, unsigned char b, unsigned char a);

[cemalgnlts]

Thanks.