first stab at hwcomposer HAL and default implementation.

Change-Id: I7ff47b94a6b34a8f61031bd94e936a088dcea6ab
diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
new file mode 100644
index 0000000..9d6a760
--- /dev/null
+++ b/include/hardware/hwcomposer.h
@@ -0,0 +1,286 @@
+/*
+ * 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_INCLUDE_HARDWARE_HWCOMPOSER_H
+#define ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+#include <hardware/hardware.h>
+#include <cutils/native_handle.h>
+
+__BEGIN_DECLS
+
+/*****************************************************************************/
+/**
+ * The id of this module
+ */
+#define HWC_HARDWARE_MODULE_ID "hwcomposer"
+
+/**
+ * Name of the sensors device to open
+ */
+#define HWC_HARDWARE_COMPOSER   "composer"
+
+
+enum {
+    /* hwc_composer_device_t::set failed in EGL */
+    HWC_EGL_ERROR = -1
+};
+
+/*
+ * hwc_layer_t::hints values
+ * Hints are set by the HAL and read by SurfaceFlinger
+ */
+enum {
+    /*
+     * HWC can set the HWC_TRIPLE_BUFFER hint to indicate to SurfaceFlinger
+     * that it should triple buffer this layer. Typically HWC does this when
+     * the layer will be unavailable for use for an extended period of time,
+     * e.g. if the display will be fetching data directly from the layer and
+     * the layer can not be modified until after the next set().
+     */
+    HWC_TRIPLE_BUFFER_HINT = 0x00000001,
+};
+
+/*
+ * hwc_layer_t::flags values
+ * Flags are set by SurfaceFlinger and read by the HAL
+ */
+enum {
+    /*
+     * HWC_SKIP_LAYER is set by SurfaceFlnger to indicate that the HAL
+     * shall not consider this layer for composition as it will be handled
+     * by SurfaceFlinger (just as if compositionType was set to HWC_OVERLAY).
+     */
+    HWC_SKIP_LAYER = 0x00000001,
+};
+
+/*
+ * hwc_layer_t::compositionType values
+ */
+enum {
+    /* this layer is to be drawn into the framebuffer by SurfaceFlinger */
+    HWC_FRAMEBUFFER = 0,
+
+    /* this layer will be handled in the HWC */
+    HWC_OVERLAY = 1,
+};
+
+/*
+ * hwc_layer_t::blending values
+ */
+enum {
+    /* no blending */
+    HWC_BLENDING_NONE     = 0x0100,
+
+    /* ONE / ONE_MINUS_SRC_ALPHA */
+    HWC_BLENDING_PREMULT  = 0x0105,
+
+    /* SRC_ALPHA / ONE_MINUS_SRC_ALPHA */
+    HWC_BLENDING_COVERAGE = 0x0405
+};
+
+/*
+ * hwc_layer_t::transform values
+ */
+enum {
+    /* flip source image horizontally */
+    HWC_TRANSFORM_FLIP_H = HAL_TRANSFORM_FLIP_H,
+    /* flip source image vertically */
+    HWC_TRANSFORM_FLIP_V = HAL_TRANSFORM_FLIP_V,
+    /* rotate source image 90 degrees clock-wise */
+    HWC_TRANSFORM_ROT_90 = HAL_TRANSFORM_ROT_90,
+    /* rotate source image 180 degrees */
+    HWC_TRANSFORM_ROT_180 = HAL_TRANSFORM_ROT_180,
+    /* rotate source image 270 degrees clock-wise */
+    HWC_TRANSFORM_ROT_270 = HAL_TRANSFORM_ROT_270,
+};
+
+typedef struct hwc_rect {
+    int left;
+    int top;
+    int right;
+    int bottom;
+} hwc_rect_t;
+
+typedef struct hwc_region {
+    size_t numRects;
+    hwc_rect_t const* rects;
+} hwc_region_t;
+
+typedef struct hwc_layer {
+    /*
+     * initially set to HWC_FRAMEBUFFER, indicates the layer will
+     * be drawn into the framebuffer using OpenGL ES.
+     * The HWC can toggle this value to HWC_OVERLAY, to indicate
+     * it will handle the layer.
+     */
+    int32_t compositionType;
+
+    /* see hwc_layer_t::hints above */
+    uint32_t hints;
+
+    /* see hwc_layer_t::flags above */
+    uint32_t flags;
+
+    /* handle of buffer to compose. this handle is guaranteed to have been
+     * allocated with gralloc */
+    native_handle_t* handle;
+
+    /* transformation to apply to the buffer during composition */
+    uint32_t transform;
+
+    /* blending to apply during composition */
+    int32_t blending;
+
+    /* area of the source to consider, the origin is the top-left corner of
+     * the buffer */
+    hwc_rect_t sourceCrop;
+
+    /* where to composite the sourceCrop onto the display. The sourceCrop
+     * is scaled using linear filtering to the displayFrame. The origin is the
+     * top-left corner of the screen.
+     */
+    hwc_rect_t displayFrame;
+
+    /* visible region in screen space. The origin is the
+     * top-left corner of the screen.
+     * The visible region INCLUDES areas overlapped by a translucent layer.
+     */
+    hwc_region_t visibleRegionScreen;
+} hwc_layer_t;
+
+
+/*
+ * hwc_layer_list_t::flags values
+ */
+enum {
+    /*
+     * HWC_GEOMETRY_CHANGED is set by SurfaceFlinger to indicate that the list
+     * passed to (*prepare)() has changed by more than just the buffer handles.
+     */
+    HWC_GEOMETRY_CHANGED = 0x00000001,
+};
+
+typedef struct hwc_layer_list {
+    uint32_t flags;
+    size_t numHwLayers;
+    hwc_layer_t hwLayers[0];
+} hwc_layer_list_t;
+
+/* This represents a display, typically an EGLDisplay object */
+typedef void* hwc_display_t;
+
+/* This represents a surface, typically an EGLSurface object  */
+typedef void* hwc_surface_t;
+
+/*****************************************************************************/
+
+
+typedef struct hwc_module {
+    struct hw_module_t common;
+} hwc_module_t;
+
+
+typedef struct hwc_composer_device {
+    struct hw_device_t common;
+
+    /*
+     * (*prepare)() is called for each frame before composition and is used by
+     * SurfaceFlinger to determine what composition steps the HWC can handle.
+     *
+     * (*prepare)() can be called more than once, the last call prevails.
+     *
+     * The HWC responds by setting the compositionType field to either
+     * HWC_FRAMEBUFFER or HWC_OVERLAY. In the former case, the composition for
+     * this layer is handled by SurfaceFlinger with OpenGL ES, in the later
+     * case, the HWC will have to handle this layer's composition.
+     *
+     * (*prepare)() is called with HWC_GEOMETRY_CHANGED to indicate that the
+     * list's geometry has changed, that is, when more than just the buffer's
+     * handles have been updated. Typically this happens (but is not limited to)
+     * when a window is added, removed, resized or moved.
+     *
+     * a NULL list parameter or a numHwLayers of zero indicates that the
+     * entire composition will be handled by SurfaceFlinger with OpenGL ES.
+     *
+     * returns: 0 on success. An negative error code on error. If an error is
+     * returned, SurfaceFlinger will assume that none of the layer will be
+     * handled by the HWC.
+     */
+    int (*prepare)(struct hwc_composer_device *dev, hwc_layer_list_t* list);
+
+
+    /*
+     * (*set)() is used in place of eglSwapBuffers(), and assumes the same
+     * functionality, except it also commits the work list atomically with
+     * the actual eglSwapBuffers().
+     *
+     * The list parameter is guaranteed to be the same as the one returned
+     * from the last call to (*prepare)().
+     *
+     * When this call returns the caller assumes that:
+     *
+     * - the display will be updated in the near future with the content
+     *   of the work list, without artifacts during the transition from the
+     *   previous frame.
+     *
+     * - all objects are available for immediate access or destruction, in
+     *   particular, hwc_region_t::rects data and hwc_layer_t::layer's buffer.
+     *   Note that this means that immediately accessing (potentially from a
+     *   different process) a buffer used in this call will not result in
+     *   screen corruption, the driver must apply proper synchronization or
+     *   scheduling (eg: block the caller, such as gralloc_module_t::lock(),
+     *   OpenGL ES, Camera, Codecs, etc..., or schedule the caller's work
+     *   after the buffer is freed from the actual composition).
+     *
+     * a NULL list parameter or a numHwLayers of zero indicates that the
+     * entire composition has been handled by SurfaceFlinger with OpenGL ES.
+     * In this case, (*set)() behaves just like eglSwapBuffers().
+     *
+     * returns: 0 on success. An negative error code on error:
+     *    HWC_EGL_ERROR: eglGetError() will provide the proper error code
+     *    Another code for non EGL errors.
+     *
+     */
+    int (*set)(struct hwc_composer_device *dev,
+                hwc_display_t dpy,
+                hwc_surface_t sur,
+                hwc_layer_list_t* list);
+
+} hwc_composer_device_t;
+
+
+/** convenience API for opening and closing a device */
+
+static inline int hwc_open(const struct hw_module_t* module,
+        hwc_composer_device_t** device) {
+    return module->methods->open(module,
+            HWC_HARDWARE_COMPOSER, (struct hw_device_t**)device);
+}
+
+static inline int hwc_close(hwc_composer_device_t* device) {
+    return device->common.close(&device->common);
+}
+
+
+/*****************************************************************************/
+
+__END_DECLS
+
+#endif /* ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H */