问题
When compiling the following C code with ndk-build in Terminal (I'm running Ubuntu):
#include <jni.h>
#include <GLES/gl.h>
#include <GLES/glext.h>
#include "org_opengldrawinjni_DrawinJNI.h"
JNIEXPORT void JNICALL Java_org_opengldrawinjni_DrawinJNI_Draw
(JNIEnv *envptr, jobject jobj)
{
GLfloat vertices[] =
{ 1.0, 0.0, 0.0,
1.0, 1.0, 0.0,
0.0, 0.0, 0.0
};
GLubyte indices[] = { 0, 1, 2 };
glVertexPointer(3, GL_FLOAT, 0, vertices);
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_BYTE, indices);
}
with this Android.mk file:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := OpenGLJNI
LOCAL_SRC_FILES := org_opengldrawinjni_DrawinJNI.c
LOCAL_LDLIBS := -llog -lGLESv1_CM.so
include $(BUILD_SHARED_LIBRARY)
I get an error, undefined reference to glVertexPointer. I'm wondering why because I believe I properly included the headers and linked up the libraries in the Android.mk
/home/thomas/Documents/LinuxProgramming/EclipseWorkspace/OpenGLDrawinginJNI/obj/local/armeabi/objs/OpenGLJNI/org_opengldrawinjni_DrawinJNI.o: In function `Java_org_opengldrawinjni_DrawinJNI_Draw':
/home/thomas/Documents/LinuxProgramming/EclipseWorkspace/OpenGLDrawinginJNI/jni/org_opengldrawinjni_DrawinJNI.c:33: undefined reference to `glVertexPointer'
collect2: ld returned 1 exit status
make: *** [/home/thomas/Documents/LinuxProgramming/EclipseWorkspace/OpenGLDrawinginJNI/obj/local/armeabi/libOpenGLJNI.so] Error 1
Thanks!
回答1:
I can't think of anything wrong but when I checked my make file there is one difference. Since I'm not good with compilers I don't know if it is relevant:
LOCAL_LDLIBS := -lGLESv1_CM -ldl -llog
Dynamic Linker Library:
is available and can be used to use the dlopen()/dlsym()/dlclose() functions provided by the Android dynamic linker. You will need to link against /system/lib/libdl.so with:
LOCAL_LDLIBS := -ldl
Hope it helps
来源:https://stackoverflow.com/questions/4221539/ndk-opengl-undefined-reference-to-glvertexpointer