Just trying the new feature java.lang.foreign to improve JME3 env settings.
I can read GLFW correctly, but got dificulty reading glGetString.
the reading should sth bigger than 12, but it seems no reading comes to the pointer.
anyone can help me ?
import java.lang.foreign.Arena;
import java.lang.foreign.FunctionDescriptor;
import java.lang.foreign.Linker;
import java.lang.foreign.MemoryLayout;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.SegmentAllocator;
import java.lang.foreign.SymbolLookup;
import java.lang.foreign.ValueLayout;
import java.lang.invoke.MethodHandle;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
*
* @author ray
*/
public class JavaApplication1 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
int ia = 0x8A2B;
Linker linker = Linker.nativeLinker();
try (Arena arena = Arena.ofConfined()) {
SymbolLookup libglfw = SymbolLookup.libraryLookup("libglfw.so", arena);
MemorySegment glfwGetString = libglfw.findOrThrow("glfwGetVersionString");
SymbolLookup libgl = SymbolLookup.libraryLookup("libGL.so", arena);
MemorySegment glGetString = libgl.findOrThrow("glGetIntegerv");
MemorySegment glvender = arena.allocate(ValueLayout.JAVA_INT);
MethodHandle glfwgetversion = linker.downcallHandle(glfwGetString, FunctionDescriptor.of(ValueLayout.ADDRESS));
MethodHandle glget = linker.downcallHandle(glGetString, FunctionDescriptor.ofVoid(ValueLayout.JAVA_INT,ValueLayout.ADDRESS));
MemorySegment ptr = (MemorySegment)glfwgetversion.invoke();
SymbolLookup stdlib = linker.defaultLookup();
MethodHandle strlen = linker.downcallHandle(stdlib.findOrThrow("strlen"), FunctionDescriptor.of(ValueLayout.JAVA_LONG, ValueLayout.ADDRESS));
long len = (long)strlen.invokeExact(ptr); // 5
System.out.println(len);
MemorySegment ptrn = ptr.reinterpret(len+1);
String strt = ptrn.getString(0);
System.out.println(strt);
//GL_MAX_VERTEX_UNIFORM_BLOCKS
//data returns one value, the maximum number of uniform blocks per vertex shader.
//The value must be at least 12. See glUniformBlockBinding
glget.invoke(0x8A2B,glvender); //GL_MAX_VERTEX_UNIFORM_BLOCKS 0x8A2B
System.out.println("MAX:"+glvender.getAtIndex(ValueLayout.JAVA_INT, 0));
} catch (Throwable ex) {
Logger.getLogger(JavaApplication1.class.getName()).log(Level.SEVERE, null, ex);
}// TODO code application logic here
}
output
46
3.2.1 Wayland EGL clock_gettime /dev/js shared
MAX:0
BUILD SUCCESSFUL (total time: 0 seconds)
System:
Linux, pre-installed glfw with : apt-get install glfw3
netbeans 23
open JDK 23.1.17
ANT project, (do not use gradle project, gradle only support jdk 22)
menu:
run → set project configuration->customize-> RUN,
set VM options: --enable-native-access=ALL-UNNAMED
future thinking:
With new foreign package , we can setup environment as we wish like choosing in multi-monitor system. or better interactive with GL or replace lwjgl with our own code.
