#define KB(x) (x*1024)
#define MB(x) (KB(x)*1024)
#define GB(x) (MB(x)*1024)

f32
Radians(f32 deg)
{
	return deg * (M_PI/180.0f); 
}

Mat4
IdentityMatrix()
{
	Mat4 mat;
	glm_mat4_identity(mat.matrix);
	return mat;
}

Mat4
Perspective(f32 fov, f32 aspect, f32 near, f32 far)
{
	Mat4 mat;
	glm_perspective(fov, aspect, near, far, mat.matrix);
	return mat;
}

Mat4
LookAt(Vec3 eye, Vec3 center, Vec3 up)
{
	Mat4 mat = IdentityMatrix();
	glm_lookat(eye.v, center.v, up.v, mat.matrix);
	return mat;
}

Mat4
Translate(Mat4 mat, Vec3 vec)
{
	Mat4 result = mat;
	glm_translate(result.matrix, vec.v);
	return result;
}

bool
StartsWith(String8 value, String8 search_string)
{
	bool result;

	if(value.length >= search_string.length)
	{
		result = strncmp((const char *)value.ptr, (const char *)search_string.ptr, search_string.length) == 0;
	}

	return result;
}

String8
SPrintf(u8 *buffer, const char *format, ...)
{
	va_list args;

	va_start(args, format);
	int written = vsprintf((char *)buffer, (char *)format, args);
	va_end(args);

	return String8(buffer);
}

String8
Copy(String8 str, u64 start, u64 end)
{
	String8 result = {
		.ptr    = ScratchAllocPtrArray<u8>(end+1-start),
		.length = end-start,
	};
	
	memcpy(result.ch_ptr, str.ch_ptr+start, result.length);	
	result.ptr[result.length] = '\0';

	return result;
}

String8
GetFilePath(String8 file_name)
{
	String8 result = file_name;

	for(u64 i = file_name.length-1; (i64)i >= 0; i -= 1)
	{
#ifdef _WIN32
		char ch = '\\';
#else
		char ch = '/';
#endif

		if(file_name[i] == ch)
		{
			result = Copy(file_name, 0, i+1);
			break;
		}
	}

	return result;
}

void
Logf(const char *format, ...)
{
	char buffer[1024];
	va_list args;
	
	va_start(args, format);
	vsprintf((char *)buffer, format, args);
	va_end(args);

	printf("%s\n", buffer);
}