Add the SurfaceTexture C++ implementation.
This change adds the C++ implementation of SurfaceTexture and related
classes. The goal of this is for a SurfaceTexture to be passed to
camera service or Stagefright in place of a Surface to allow camera
preview or decoded video frames to be streamed to an OpenGL ES texture
that an application can use.
Change-Id: I55c83a7017f1ecb81c9c9e3252cbd118b914296c
diff --git a/include/gui/SurfaceTexture.h b/include/gui/SurfaceTexture.h
new file mode 100644
index 0000000..ff92e08
--- /dev/null
+++ b/include/gui/SurfaceTexture.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_GUI_SURFACETEXTURE_H
+#define ANDROID_GUI_SURFACETEXTURE_H
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <GLES2/gl2.h>
+
+#include <gui/ISurfaceTexture.h>
+
+#include <ui/GraphicBuffer.h>
+
+#include <utils/threads.h>
+
+#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture"
+
+namespace android {
+// ----------------------------------------------------------------------------
+
+class SurfaceTexture : public BnSurfaceTexture {
+public:
+ enum { MIN_BUFFER_SLOTS = 3 };
+ enum { NUM_BUFFER_SLOTS = 32 };
+
+ // tex indicates the name OpenGL texture to which images are to be streamed.
+ // This texture name cannot be changed once the SurfaceTexture is created.
+ SurfaceTexture(GLuint tex);
+
+ virtual ~SurfaceTexture();
+
+ // setBufferCount updates the number of available buffer slots. After
+ // calling this all buffer slots are both unallocated and owned by the
+ // SurfaceTexture object (i.e. they are not owned by the client).
+ virtual status_t setBufferCount(int bufferCount);
+
+ virtual sp<GraphicBuffer> requestBuffer(int buf, uint32_t w, uint32_t h,
+ uint32_t format, uint32_t usage);
+
+ // dequeueBuffer gets the next buffer slot index for the client to use. If a
+ // buffer slot is available then that slot index is written to the location
+ // pointed to by the buf argument and a status of OK is returned. If no
+ // slot is available then a status of -EBUSY is returned and buf is
+ // unmodified.
+ virtual status_t dequeueBuffer(int *buf);
+
+ virtual status_t queueBuffer(int buf);
+ virtual void cancelBuffer(int buf);
+ virtual status_t setCrop(const Rect& reg);
+ virtual status_t setTransform(uint32_t transform);
+
+ // updateTexImage sets the image contents of the target texture to that of
+ // the most recently queued buffer.
+ //
+ // This call may only be made while the OpenGL ES context to which the
+ // target texture belongs is bound to the calling thread.
+ status_t updateTexImage();
+
+private:
+
+ // freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for
+ // all slots.
+ void freeAllBuffers();
+
+ // createImage creates a new EGLImage from a GraphicBuffer.
+ EGLImageKHR createImage(EGLDisplay dpy,
+ const sp<GraphicBuffer>& graphicBuffer);
+
+ enum { INVALID_BUFFER_SLOT = -1 };
+
+ struct BufferSlot {
+ // mGraphicBuffer points to the buffer allocated for this slot or is NULL
+ // if no buffer has been allocated.
+ sp<GraphicBuffer> mGraphicBuffer;
+
+ // mEglImage is the EGLImage created from mGraphicBuffer.
+ EGLImageKHR mEglImage;
+
+ // mEglDisplay is the EGLDisplay used to create mEglImage.
+ EGLDisplay mEglDisplay;
+
+ // mOwnedByClient indicates whether the slot is currently accessible to a
+ // client and should not be used by the SurfaceTexture object. It gets
+ // set to true when dequeueBuffer returns the slot and is reset to false
+ // when the client calls either queueBuffer or cancelBuffer on the slot.
+ bool mOwnedByClient;
+ };
+
+ // mSlots is the array of buffer slots that must be mirrored on the client
+ // side. This allows buffer ownership to be transferred between the client
+ // and server without sending a GraphicBuffer over binder. The entire array
+ // is initialized to NULL at construction time, and buffers are allocated
+ // for a slot when requestBuffer is called with that slot's index.
+ BufferSlot mSlots[NUM_BUFFER_SLOTS];
+
+ // mBufferCount is the number of buffer slots that the client and server
+ // must maintain. It defaults to MIN_BUFFER_SLOTS and can be changed by
+ // calling setBufferCount.
+ int mBufferCount;
+
+ // mCurrentTexture is the buffer slot index of the buffer that is currently
+ // bound to the OpenGL texture. A value of INVALID_BUFFER_SLOT, indicating
+ // that no buffer is currently bound to the texture.
+ int mCurrentTexture;
+
+ // mLastQueued is the buffer slot index of the most recently enqueued buffer.
+ // At construction time it is initialized to INVALID_BUFFER_SLOT, and is
+ // updated each time queueBuffer is called.
+ int mLastQueued;
+
+ // mTexName is the name of the OpenGL texture to which streamed images will
+ // be bound when updateTexImage is called. It is set at construction time
+ // changed with a call to setTexName.
+ const GLuint mTexName;
+
+ // mMutex is the mutex used to prevent concurrent access to the member
+ // variables of SurfaceTexture objects. It must be locked whenever the
+ // member variables are accessed.
+ Mutex mMutex;
+};
+
+// ----------------------------------------------------------------------------
+}; // namespace android
+
+#endif // ANDROID_GUI_SURFACETEXTURE_H