Add glReadPixels with buffer-offset argument

- For reading into PBOs on GLES3, add an overloaded version of
  glReadPixels that takes an offset argument.

Bug 18878609

Change-Id: I744483deab6358a66b0dc5e87be1ae2b96560ac1

api/current.txt

@@ -26851,6 +26851,7 @@ package android.opengl {
     method public static void glProgramBinary(int, int, java.nio.Buffer, int);
     method public static void glProgramParameteri(int, int, int);
     method public static void glReadBuffer(int);
+    method public static void glReadPixels(int, int, int, int, int, int, int);
     method public static void glRenderbufferStorageMultisample(int, int, int, int, int);
     method public static void glResumeTransformFeedback();
     method public static void glSamplerParameterf(int, int, float);

api/system-current.txt

@@ -29143,6 +29143,7 @@ package android.opengl {
     method public static void glProgramBinary(int, int, java.nio.Buffer, int);
     method public static void glProgramParameteri(int, int, int);
     method public static void glReadBuffer(int);
+    method public static void glReadPixels(int, int, int, int, int, int, int);
     method public static void glRenderbufferStorageMultisample(int, int, int, int, int);
     method public static void glResumeTransformFeedback();
     method public static void glSamplerParameterf(int, int, float);

api/test-current.txt

@@ -26860,6 +26860,7 @@ package android.opengl {
     method public static void glProgramBinary(int, int, java.nio.Buffer, int);
     method public static void glProgramParameteri(int, int, int);
     method public static void glReadBuffer(int);
+    method public static void glReadPixels(int, int, int, int, int, int, int);
     method public static void glRenderbufferStorageMultisample(int, int, int, int, int);
     method public static void glResumeTransformFeedback();
     method public static void glSamplerParameterf(int, int, float);

core/jni/android_opengl_GLES30.cpp

@@ -5155,6 +5155,21 @@ android_glGetInternalformativ__IIIILjava_nio_IntBuffer_2
     }
 }
 
+/* void glReadPixels ( GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLint offset ) */
+static void
+android_glReadPixels__IIIIIII
+  (JNIEnv *_env, jobject _this, jint x, jint y, jint width, jint height, jint format, jint type, jint offset) {
+    glReadPixels(
+        (GLint)x,
+        (GLint)y,
+        (GLsizei)width,
+        (GLsizei)height,
+        (GLenum)format,
+        (GLenum)type,
+        reinterpret_cast<GLvoid *>(offset)
+    );
+}
+
 static const char *classPathName = "android/opengl/GLES30";
 
 static const JNINativeMethod methods[] = {
@@ -5320,6 +5335,7 @@ static const JNINativeMethod methods[] = {
 {"glTexStorage3D", "(IIIIII)V", (void *) android_glTexStorage3D__IIIIII },
 {"glGetInternalformativ", "(IIII[II)V", (void *) android_glGetInternalformativ__IIII_3II },
 {"glGetInternalformativ", "(IIIILjava/nio/IntBuffer;)V", (void *) android_glGetInternalformativ__IIIILjava_nio_IntBuffer_2 },
+{"glReadPixels", "(IIIIIII)V", (void *) android_glReadPixels__IIIIIII },
 };
 
 int register_android_opengl_jni_GLES30(JNIEnv *_env)

opengl/java/android/opengl/GLES30.java

@@ -1791,4 +1791,16 @@ public class GLES30 extends GLES20 {
         java.nio.IntBuffer params
     );
 
+    // C function void glReadPixels ( GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLint offset )
+
+    public static native void glReadPixels(
+        int x,
+        int y,
+        int width,
+        int height,
+        int format,
+        int type,
+        int offset
+    );
+
 }