如何在Java，Android中初始化巨大的float数组？

Question

I was creating a opengl android application. I was trying to render a opengl object with vertices more than 50,000.

float itemVerts [] = {
// f 231/242/231 132/142/132 131/141/131
0.172233487787643f, -0.0717437751698985f, 0.228589675538813f,
0.176742968653347f, -0.0680393472738536f, 0.2284149434494f,
0.167979223684599f, -0.0670168837233226f, 0.24286384937854f,
// f 131/141/131 230/240/230 231/242/231
0.167979223684599f, -0.0670168837233226f, 0.24286384937854f,
0.166391290343292f, -0.0686544011752973f, 0.241920432968569f,......

and many more.... But when i do this in a function or constructor i get a error while compiling that The code of method () is exceeding the 65535 bytes limit. So I was wondering if there is a different way to do this.

I tried storing the value in file and reading it back. But the IO operation, with string parsing of such huge record is very slow. Takes more than 60 sec. Which is not good.

Please let me know if there is any other way to do this. Thank you for your time and help.

Answer 1

But when i do this in a function or constructor i get a error while compiling that The code of method () is exceeding the 65535 bytes limit. So I was wondering if there is a different way to do this.

Put it outside the constructor (as a class variable or field)? If this doesn't change, just make it a constant. If it does change, make it a constant anyway and copy it in the constructor.

I tried storing the value in file and reading it back. But the IO operation, with string parsing of such huge record is very slow. Takes more than 60 sec. Which is not good.

If you do decide to keep it in an external file and read it in, don't read it as a string, just serialize it somehow (Java serialization, Protocol Buffers, etc.).

Answer 2

The program don't have to parse the float if we preprocess the data.

Write another program that write all float to a binary file using DataOutputStream .

In your program, read them back using DataInputStream . You might want to chain it with BufferedInputStream .

Answer 3

对于这种情况，我通常使用assets文件夹以二进制格式存储文件（即使您可以定义某种文件格式以包括顶点，法线等），也可以在应用程序初始化时将其分配，如wannik解释的那样。

Answer 4

I would proprocess and store floats in binary form, then mmap it as byte buffer and create fload array out of it. This way you get float array, without parsing or allocation of space.