am 71aa2fca: Merge "EmuGL: Deliver every frame to a callback"

* commit '71aa2fcac1cd1e5d59c210b5dd332ca4aefba530':
  EmuGL: Deliver every frame to a callback

tools/emulator/opengl/host/include/libOpenglRender/render_api.h

@@ -22,6 +22,38 @@ extern "C" {
 
 #include "render_api_platform_types.h"
 
+/* If a function with this signature is passed to initOpenGLRenderer(),
+ * it will be called by the renderer just before each new frame is displayed,
+ * providing a copy of the framebuffer contents.
+ *
+ * The callback will be called from one of the renderer's threads, so will
+ * probably need synchronization on any data structures it modifies. The
+ * pixels buffer may be overwritten as soon as the callback returns; if it needs
+ * the pixels afterwards it must copy them.
+ *
+ * The pixels buffer is intentionally not const: the callback may modify the
+ * data without copying to another buffer if it wants, e.g. in-place RGBA to RGB
+ * conversion, or in-place y-inversion.
+ *
+ * Parameters are:
+ *   context        The pointer optionally provided when the callback was
+ *                  registered. The client can use this to pass whatever
+ *                  information it wants to the callback.
+ *   width, height  Dimensions of the image, in pixels. Rows are tightly packed;
+ *                  there is no inter-row padding.
+ *   ydir           Indicates row order: 1 means top-to-bottom order, -1 means
+ *                  bottom-to-top order.
+ *   format, type   Format and type GL enums, as used in glTexImage2D() or
+ *                  glReadPixels(), describing the pixel format.
+ *   pixels         The framebuffer image.
+ *
+ * In the first implementation, ydir is always -1 (bottom to top), format and
+ * type are always GL_RGBA and GL_UNSIGNED_BYTE, and the width and height will
+ * always be the same as the ones passed to initOpenGLRenderer().
+ */
+typedef void (*OnPostFn)(void* context, int width, int height, int ydir,
+                         int format, int type, unsigned char* pixels);
+
 // initLibrary - initialize the library and tries to load the corresponding
 //     GLES translator libraries. This function must be called before anything
 //     else to ensure that everything works. If it returns an error, then
@@ -53,8 +85,8 @@ int setStreamMode(int mode);
 // This function is *NOT* thread safe and should be called first
 // to initialize the renderer after initLibrary().
 //
-bool initOpenGLRenderer(int width, int height, int portNum);
-
+bool initOpenGLRenderer(int width, int height, int portNum,
+                        OnPostFn onPost, void* onPostContext);
 
 //
 // createOpenGLSubwindow -