Add ANativeWindow dataSpace; update graphics formats, color spaces

First stage of adding a new dataSpace field for ANativeWindow,
for communicating format- (and endpoint-) dependent information
about graphics buffers. For most formats, dataSpace describes the
color space of the buffer, while format describes the memory layout.

For some formats, the dataSpace may also specify that the buffer
contains depth measurements, encoded images, or other kinds of
information that is not necessarily a simple 2D image.
Rename the existing colorspace enumeration to dataspace, with an added
dataspace for depth, and sRGB gamma-corrected and linear colorspaces.

Add in a definition for Android depth point clouds as a
variable-length list of float-triplet coordinates, as the underlying
layout of buffers with format HAL_PIXEL_FORMAT_BLOB and dataSpace of
HAL_DATASPACE_DEPTH.

Also remove now-unnecessary sRGB HAL graphics formats, and remove the
alias RAW_SENSOR that was left in to ease transition to RAW16.

Change-Id: I8797f67fb9c2b18da5975f2145303ca0bf98e62d

2 files changed, 196 insertions, 41 deletions

diff --git a/include/system/graphics.h b/include/system/graphics.h
index c3fca97..c9f5950 100644
--- a/include/system/graphics.h
+++ b/include/system/graphics.h
@@ -45,9 +45,12 @@ enum {
     /*
      * "linear" color pixel formats:
      *
-     * The pixel formats below contain sRGB data but are otherwise treated
-     * as linear formats, i.e.: no special operation is performed when
-     * reading or writing into a buffer in one of these formats
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer.
+     *
+     * The color space determines, for example, if the formats are linear or
+     * gamma-corrected; or whether any special operations are performed when
+     * reading or writing into a buffer in one of these formats.
      */
     HAL_PIXEL_FORMAT_RGBA_8888          = 1,
     HAL_PIXEL_FORMAT_RGBX_8888          = 2,
@@ -56,28 +59,6 @@ enum {
     HAL_PIXEL_FORMAT_BGRA_8888          = 5,
 
     /*
-     * sRGB color pixel formats:
-     *
-     * The red, green and blue components are stored in sRGB space, and converted
-     * to linear space when read, using the standard sRGB to linear equation:
-     *
-     * Clinear = Csrgb / 12.92                  for Csrgb <= 0.04045
-     *         = (Csrgb + 0.055 / 1.055)^2.4    for Csrgb >  0.04045
-     *
-     * When written the inverse transformation is performed:
-     *
-     * Csrgb = 12.92 * Clinear                  for Clinear <= 0.0031308
-     *       = 1.055 * Clinear^(1/2.4) - 0.055  for Clinear >  0.0031308
-     *
-     *
-     *  The alpha component, if present, is always stored in linear space and
-     *  is left unmodified when read or written.
-     *
-     */
-    HAL_PIXEL_FORMAT_sRGB_A_8888        = 0xC,
-    HAL_PIXEL_FORMAT_sRGB_X_8888        = 0xD,
-
-    /*
      * 0x100 - 0x1FF
      *
      * This range is reserved for pixel formats that are specific to the HAL
@@ -111,6 +92,8 @@ enum {
      *   cr_offset = y_size
      *   cb_offset = y_size + c_size
      *
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer.
      */
     HAL_PIXEL_FORMAT_YV12   = 0x32315659, // YCrCb 4:2:0 Planar
 
@@ -135,6 +118,8 @@ enum {
      *
      *   size = stride * height
      *
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer.
      */
     HAL_PIXEL_FORMAT_Y8     = 0x20203859,
 
@@ -159,6 +144,10 @@ enum {
      *
      *   size = stride * height * 2
      *
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer, except that dataSpace field
+     * HAL_DATASPACE_DEPTH indicates that this buffer contains a depth
+     * image where each sample is a distance value measured by a depth camera.
      */
     HAL_PIXEL_FORMAT_Y16    = 0x20363159,
 
@@ -167,7 +156,7 @@ enum {
      *
      * This format is exposed outside of the camera HAL to applications.
      *
-     * RAW_SENSOR is a single-channel, 16-bit, little endian  format, typically
+     * RAW16 is a single-channel, 16-bit, little endian format, typically
      * representing raw Bayer-pattern images from an image sensor, with minimal
      * processing.
      *
@@ -193,9 +182,12 @@ enum {
      *    - GRALLOC_USAGE_HW_CAMERA_*
      *    - GRALLOC_USAGE_SW_*
      *    - GRALLOC_USAGE_RENDERSCRIPT
+     *
+     * When used with ANativeWindow, the dataSpace should be
+     * HAL_DATASPACE_ARBITRARY, as raw image sensor buffers require substantial
+     * extra metadata to define.
      */
     HAL_PIXEL_FORMAT_RAW16 = 0x20,
-    HAL_PIXEL_FORMAT_RAW_SENSOR = 0x20, // TODO(rubenbrunk): Remove RAW_SENSOR.
 
     /*
      * Android RAW10 format:
@@ -244,6 +236,10 @@ enum {
      *    - GRALLOC_USAGE_HW_CAMERA_*
      *    - GRALLOC_USAGE_SW_*
      *    - GRALLOC_USAGE_RENDERSCRIPT
+     *
+     * When used with ANativeWindow, the dataSpace field should be
+     * HAL_DATASPACE_ARBITRARY, as raw image sensor buffers require substantial
+     * extra metadata to define.
      */
     HAL_PIXEL_FORMAT_RAW10 = 0x25,
 
@@ -261,6 +257,10 @@ enum {
      *    - GRALLOC_USAGE_HW_CAMERA_*
      *    - GRALLOC_USAGE_SW_*
      *    - GRALLOC_USAGE_RENDERSCRIPT
+     *
+     * When used with ANativeWindow, the dataSpace field should be
+     * HAL_DATASPACE_ARBITRARY, as raw image sensor buffers require substantial
+     * extra metadata to define.
      */
     HAL_PIXEL_FORMAT_RAW_OPAQUE = 0x24,
 
@@ -276,6 +276,16 @@ enum {
      *
      * Buffers of this format must have a height of 1, and width equal to their
      * size in bytes.
+     *
+     * When used with ANativeWindow, the mapping of the dataSpace field to
+     * buffer contents for BLOB is as follows:
+     *
+     *  dataSpace value               | Buffer contents
+     * -------------------------------+-----------------------------------------
+     *  HAL_DATASPACE_JFIF            | An encoded JPEG image
+     *  HAL_DATASPACE_DEPTH           | An android_depth_points buffer
+     *  Other                         | Unsupported
+     *
      */
     HAL_PIXEL_FORMAT_BLOB = 0x21,
 
@@ -292,6 +302,8 @@ enum {
      * framework will assume that sampling the texture will always return an
      * alpha value of 1.0 (i.e. the buffer contains only opaque pixel values).
      *
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer.
      */
     HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED = 0x22,
 
@@ -311,6 +323,9 @@ enum {
      *
      * This format is locked for use by gralloc's (*lock_ycbcr) method, and
      * locking with the (*lock) method will return an error.
+     *
+     * When used with ANativeWindow, the dataSpace field describes the color
+     * space of the buffer.
      */
     HAL_PIXEL_FORMAT_YCbCr_420_888 = 0x23,
 
@@ -355,6 +370,42 @@ struct android_ycbcr {
 };
 
 /**
+ * Structure used to define depth point clouds for format HAL_PIXEL_FORMAT_BLOB
+ * with dataSpace value of HAL_DATASPACE_DEPTH.
+ * When locking a native buffer of the above format and dataSpace value,
+ * the vaddr pointer can be cast to this structure.
+ *
+ * A variable-length list of (x,y,z) 3D points, as floats.
+ *
+ * @num_points is the number of points in the list
+ *
+ * @xyz_points is the flexible array of floating-point values.
+ *   It contains (num_points) * 3 floats.
+ *
+ *   For example:
+ *     android_depth_points d = get_depth_buffer();
+ *     struct {
+ *       float x; float y; float z;
+ *     } firstPoint, lastPoint;
+ *
+ *     firstPoint.x = d.xyz_points[0];
+ *     firstPoint.y = d.xyz_points[1];
+ *     firstPoint.z = d.xyz_points[2];
+ *     lastPoint.x = d.xyz_points[(d.num_points - 1) * 3 + 0];
+ *     lastPoint.y = d.xyz_points[(d.num_points - 1) * 3 + 1];
+ *     lastPoint.z = d.xyz_points[(d.num_points - 1) * 3 + 2];
+ */
+
+struct android_depth_points {
+    uint32_t num_points;
+
+    /** reserved for future use, set to 0 by gralloc's (*lock)() */
+    uint32_t reserved[8];
+
+    float xyz_points[];
+};
+
+/**
  * Transformation definitions
  *
  * IMPORTANT NOTE:
@@ -378,19 +429,33 @@ enum {
 };
 
 /**
- * Colorspace Definitions
+ * Dataspace Definitions
  * ======================
  *
- * Colorspace is the definition of how pixel values should be interpreted.
- * It includes primaries (including white point) and the transfer
- * characteristic function, which describes both gamma curve and numeric
- * range (within the bit depth).
+ * Dataspace is the definition of how pixel values should be interpreted.
+ *
+ * For many formats, this is the colorspace of the image data, which includes
+ * primaries (including white point) and the transfer characteristic function,
+ * which describes both gamma curve and numeric range (within the bit depth).
+ *
+ * Other dataspaces include depth measurement data from a depth camera.
  */
 
-enum {
+typedef enum android_dataspace {
+    /*
+     * Default-assumption data space, when not explicitly specified.
+     *
+     * It is safest to assume the buffer is an image with sRGB primaries and
+     * encoding ranges, but the consumer and/or the producer of the data may
+     * simply be using defaults. No automatic gamma transform should be
+     * expected, except for a possible display gamma transform when drawn to a
+     * screen.
+     */
+    HAL_DATASPACE_UNKNOWN = 0x0,
+
     /*
-     * Arbitrary colorspace with manually defined characteristics.
-     * Colorspace definition must be communicated separately.
+     * Arbitrary dataspace with manually defined characteristics.  Definition
+     * for colorspaces or other meaning must be communicated separately.
      *
      * This is used when specifying primaries, transfer characteristics,
      * etc. separately.
@@ -399,7 +464,57 @@ enum {
      * where a colorspace can have separately defined primaries, transfer
      * characteristics, etc.
      */
-    HAL_COLORSPACE_ARBITRARY = 0x1,
+    HAL_DATASPACE_ARBITRARY = 0x1,
+
+    /*
+     * RGB Colorspaces
+     * -----------------
+     *
+     * Primaries are given using (x,y) coordinates in the CIE 1931 definition
+     * of x and y specified by ISO 11664-1.
+     *
+     * Transfer characteristics are the opto-electronic transfer characteristic
+     * at the source as a function of linear optical intensity (luminance).
+     */
+
+    /*
+     * sRGB linear encoding:
+     *
+     * The red, green, and blue components are stored in sRGB space, but
+     * are linear, not gamma-encoded.
+     * The RGB primaries and the white point are the same as BT.709.
+     *
+     * The values are encoded using the full range ([0,255] for 8-bit) for all
+     * components.
+     */
+    HAL_DATASPACE_SRGB_LINEAR = 0x200,
+
+    /*
+     * sRGB gamma encoding:
+     *
+     * The red, green and blue components are stored in sRGB space, and
+     * converted to linear space when read, using the standard sRGB to linear
+     * equation:
+     *
+     * Clinear = Csrgb / 12.92                  for Csrgb <= 0.04045
+     *         = (Csrgb + 0.055 / 1.055)^2.4    for Csrgb >  0.04045
+     *
+     * When written the inverse transformation is performed:
+     *
+     * Csrgb = 12.92 * Clinear                  for Clinear <= 0.0031308
+     *       = 1.055 * Clinear^(1/2.4) - 0.055  for Clinear >  0.0031308
+     *
+     *
+     * The alpha component, if present, is always stored in linear space and
+     * is left unmodified when read or written.
+     *
+     * The RGB primaries and the white point are the same as BT.709.
+     *
+     * The values are encoded using the full range ([0,255] for 8-bit) for all
+     * components.
+     *
+     */
+    HAL_DATASPACE_SRGB = 0x201,
 
     /*
      * YCbCr Colorspaces
@@ -429,7 +544,7 @@ enum {
      *  red             0.640   0.330
      *  white (D65)     0.3127  0.3290
      */
-    HAL_COLORSPACE_JFIF = 0x101,
+    HAL_DATASPACE_JFIF = 0x101,
 
     /*
      * ITU-R Recommendation 601 (BT.601) - 625-line
@@ -456,7 +571,7 @@ enum {
      *  red             0.640   0.330
      *  white (D65)     0.3127  0.3290
      */
-    HAL_COLORSPACE_BT601_625 = 0x102,
+    HAL_DATASPACE_BT601_625 = 0x102,
 
     /*
      * ITU-R Recommendation 601 (BT.601) - 525-line
@@ -483,7 +598,7 @@ enum {
      *  red             0.630   0.340
      *  white (D65)     0.3127  0.3290
      */
-    HAL_COLORSPACE_BT601_525 = 0x103,
+    HAL_DATASPACE_BT601_525 = 0x103,
 
     /*
      * ITU-R Recommendation 709 (BT.709)
@@ -504,8 +619,20 @@ enum {
      *  red             0.640   0.330
      *  white (D65)     0.3127  0.3290
      */
-    HAL_COLORSPACE_BT709 = 0x104,
-};
+    HAL_DATASPACE_BT709 = 0x104,
+
+    /*
+     * The buffer contains depth ranging measurements from a depth camera.
+     * This value is valid with formats:
+     *    HAL_PIXEL_FORMAT_Y16: 16-bit single channel depth image.
+     *    HAL_PIXEL_FORMAT_BLOB: A depth point cloud, as
+     *       a variable-length float (x,y,z) coordinate point list.
+     *       The point cloud will be represented with the android_depth_points
+     *       structure.
+     */
+    HAL_DATASPACE_DEPTH = 0x1000
+
+} android_dataspace_t;
 
 #ifdef __cplusplus
 }
diff --git a/include/system/window.h b/include/system/window.h
index bf93b79..af0418b 100644
--- a/include/system/window.h
+++ b/include/system/window.h
@@ -262,6 +262,12 @@ enum {
      * the aspect ratio of the buffers produced.
      */
     NATIVE_WINDOW_STICKY_TRANSFORM = 11,
+
+    /**
+     * The default data space for the buffers as set by the consumer.
+     * The values are defined in graphics.h.
+     */
+    NATIVE_WINDOW_DEFAULT_DATASPACE = 12
 };
 
 /* Valid operations for the (*perform)() hook.
@@ -294,6 +300,7 @@ enum {
     NATIVE_WINDOW_SET_POST_TRANSFORM_CROP   = 16,   /* private */
     NATIVE_WINDOW_SET_BUFFERS_STICKY_TRANSFORM = 17,/* private */
     NATIVE_WINDOW_SET_SIDEBAND_STREAM       = 18,
+    NATIVE_WINDOW_SET_BUFFERS_DATASPACE     = 19
 };
 
 /* parameter for NATIVE_WINDOW_[API_][DIS]CONNECT */
@@ -498,6 +505,7 @@ struct ANativeWindow
      *     NATIVE_WINDOW_SET_BUFFERS_GEOMETRY  (deprecated)
      *     NATIVE_WINDOW_SET_BUFFERS_TRANSFORM
      *     NATIVE_WINDOW_SET_BUFFERS_TIMESTAMP
+     *     NATIVE_WINDOW_SET_BUFFERS_DATASPACE
      *     NATIVE_WINDOW_SET_BUFFERS_DIMENSIONS
      *     NATIVE_WINDOW_SET_BUFFERS_FORMAT
      *     NATIVE_WINDOW_SET_SCALING_MODE       (private)
@@ -799,6 +807,26 @@ static inline int native_window_set_buffers_format(
 }
 
 /*
+ * native_window_set_buffers_data_space(..., int dataSpace)
+ * All buffers queued after this call will be associated with the dataSpace
+ * parameter specified.
+ *
+ * dataSpace specifies additional information about the buffer that's dependent
+ * on the buffer format and the endpoints. For example, it can be used to convey
+ * the color space of the image data in the buffer, or it can be used to
+ * indicate that the buffers contain depth measurement data instead of color
+ * images.  The default dataSpace is 0, HAL_DATASPACE_UNKNOWN, unless it has been
+ * overridden by the consumer.
+ */
+static inline int native_window_set_buffers_data_space(
+        struct ANativeWindow* window,
+        android_dataspace_t dataSpace)
+{
+    return window->perform(window, NATIVE_WINDOW_SET_BUFFERS_DATASPACE,
+            dataSpace);
+}
+
+/*
  * native_window_set_buffers_transform(..., int transform)
  * All buffers queued after this call will be displayed transformed according
  * to the transform parameter specified.