gpu_buffer: add bytes_per_pixel method to Format

TEST=cargo test -p gpu_buffer
BUG=None

Change-Id: I39f825065b6dd2904d81ae3baf76b3552c739691
Reviewed-on: https://chromium-review.googlesource.com/1102111
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

2 files changed, 168 insertions, 0 deletions

diff --git a/gpu_buffer/src/drm_formats.rs b/gpu_buffer/src/drm_formats.rs
new file mode 100644
index 0000000..bad5646
--- /dev/null
+++ b/gpu_buffer/src/drm_formats.rs
@@ -0,0 +1,72 @@
+// Copyright 2018 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#![allow(dead_code)]
+
+pub const DRM_FORMAT_C8: [u8; 4] = [b'C', b'8', b' ', b' '];
+pub const DRM_FORMAT_R8: [u8; 4] = [b'R', b'8', b' ', b' '];
+pub const DRM_FORMAT_R16: [u8; 4] = [b'R', b'1', b'6', b' '];
+pub const DRM_FORMAT_RG88: [u8; 4] = [b'R', b'G', b'8', b'8'];
+pub const DRM_FORMAT_GR88: [u8; 4] = [b'G', b'R', b'8', b'8'];
+pub const DRM_FORMAT_RG1616: [u8; 4] = [b'R', b'G', b'3', b'2'];
+pub const DRM_FORMAT_GR1616: [u8; 4] = [b'G', b'R', b'3', b'2'];
+pub const DRM_FORMAT_RGB332: [u8; 4] = [b'R', b'G', b'B', b'8'];
+pub const DRM_FORMAT_BGR233: [u8; 4] = [b'B', b'G', b'R', b'8'];
+pub const DRM_FORMAT_XRGB4444: [u8; 4] = [b'X', b'R', b'1', b'2'];
+pub const DRM_FORMAT_XBGR4444: [u8; 4] = [b'X', b'B', b'1', b'2'];
+pub const DRM_FORMAT_RGBX4444: [u8; 4] = [b'R', b'X', b'1', b'2'];
+pub const DRM_FORMAT_BGRX4444: [u8; 4] = [b'B', b'X', b'1', b'2'];
+pub const DRM_FORMAT_ARGB4444: [u8; 4] = [b'A', b'R', b'1', b'2'];
+pub const DRM_FORMAT_ABGR4444: [u8; 4] = [b'A', b'B', b'1', b'2'];
+pub const DRM_FORMAT_RGBA4444: [u8; 4] = [b'R', b'A', b'1', b'2'];
+pub const DRM_FORMAT_BGRA4444: [u8; 4] = [b'B', b'A', b'1', b'2'];
+pub const DRM_FORMAT_XRGB1555: [u8; 4] = [b'X', b'R', b'1', b'5'];
+pub const DRM_FORMAT_XBGR1555: [u8; 4] = [b'X', b'B', b'1', b'5'];
+pub const DRM_FORMAT_RGBX5551: [u8; 4] = [b'R', b'X', b'1', b'5'];
+pub const DRM_FORMAT_BGRX5551: [u8; 4] = [b'B', b'X', b'1', b'5'];
+pub const DRM_FORMAT_ARGB1555: [u8; 4] = [b'A', b'R', b'1', b'5'];
+pub const DRM_FORMAT_ABGR1555: [u8; 4] = [b'A', b'B', b'1', b'5'];
+pub const DRM_FORMAT_RGBA5551: [u8; 4] = [b'R', b'A', b'1', b'5'];
+pub const DRM_FORMAT_BGRA5551: [u8; 4] = [b'B', b'A', b'1', b'5'];
+pub const DRM_FORMAT_RGB565: [u8; 4] = [b'R', b'G', b'1', b'6'];
+pub const DRM_FORMAT_BGR565: [u8; 4] = [b'B', b'G', b'1', b'6'];
+pub const DRM_FORMAT_RGB888: [u8; 4] = [b'R', b'G', b'2', b'4'];
+pub const DRM_FORMAT_BGR888: [u8; 4] = [b'B', b'G', b'2', b'4'];
+pub const DRM_FORMAT_XRGB8888: [u8; 4] = [b'X', b'R', b'2', b'4'];
+pub const DRM_FORMAT_XBGR8888: [u8; 4] = [b'X', b'B', b'2', b'4'];
+pub const DRM_FORMAT_RGBX8888: [u8; 4] = [b'R', b'X', b'2', b'4'];
+pub const DRM_FORMAT_BGRX8888: [u8; 4] = [b'B', b'X', b'2', b'4'];
+pub const DRM_FORMAT_ARGB8888: [u8; 4] = [b'A', b'R', b'2', b'4'];
+pub const DRM_FORMAT_ABGR8888: [u8; 4] = [b'A', b'B', b'2', b'4'];
+pub const DRM_FORMAT_RGBA8888: [u8; 4] = [b'R', b'A', b'2', b'4'];
+pub const DRM_FORMAT_BGRA8888: [u8; 4] = [b'B', b'A', b'2', b'4'];
+pub const DRM_FORMAT_XRGB2101010: [u8; 4] = [b'X', b'R', b'3', b'0'];
+pub const DRM_FORMAT_XBGR2101010: [u8; 4] = [b'X', b'B', b'3', b'0'];
+pub const DRM_FORMAT_RGBX1010102: [u8; 4] = [b'R', b'X', b'3', b'0'];
+pub const DRM_FORMAT_BGRX1010102: [u8; 4] = [b'B', b'X', b'3', b'0'];
+pub const DRM_FORMAT_ARGB2101010: [u8; 4] = [b'A', b'R', b'3', b'0'];
+pub const DRM_FORMAT_ABGR2101010: [u8; 4] = [b'A', b'B', b'3', b'0'];
+pub const DRM_FORMAT_RGBA1010102: [u8; 4] = [b'R', b'A', b'3', b'0'];
+pub const DRM_FORMAT_BGRA1010102: [u8; 4] = [b'B', b'A', b'3', b'0'];
+pub const DRM_FORMAT_YUYV: [u8; 4] = [b'Y', b'U', b'Y', b'V'];
+pub const DRM_FORMAT_YVYU: [u8; 4] = [b'Y', b'V', b'Y', b'U'];
+pub const DRM_FORMAT_UYVY: [u8; 4] = [b'U', b'Y', b'V', b'Y'];
+pub const DRM_FORMAT_VYUY: [u8; 4] = [b'V', b'Y', b'U', b'Y'];
+pub const DRM_FORMAT_AYUV: [u8; 4] = [b'A', b'Y', b'U', b'V'];
+pub const DRM_FORMAT_NV12: [u8; 4] = [b'N', b'V', b'1', b'2'];
+pub const DRM_FORMAT_NV21: [u8; 4] = [b'N', b'V', b'2', b'1'];
+pub const DRM_FORMAT_NV16: [u8; 4] = [b'N', b'V', b'1', b'6'];
+pub const DRM_FORMAT_NV61: [u8; 4] = [b'N', b'V', b'6', b'1'];
+pub const DRM_FORMAT_NV24: [u8; 4] = [b'N', b'V', b'2', b'4'];
+pub const DRM_FORMAT_NV42: [u8; 4] = [b'N', b'V', b'4', b'2'];
+pub const DRM_FORMAT_YUV410: [u8; 4] = [b'Y', b'U', b'V', b'9'];
+pub const DRM_FORMAT_YVU410: [u8; 4] = [b'Y', b'V', b'U', b'9'];
+pub const DRM_FORMAT_YUV411: [u8; 4] = [b'Y', b'U', b'1', b'1'];
+pub const DRM_FORMAT_YVU411: [u8; 4] = [b'Y', b'V', b'1', b'1'];
+pub const DRM_FORMAT_YUV420: [u8; 4] = [b'Y', b'U', b'1', b'2'];
+pub const DRM_FORMAT_YVU420: [u8; 4] = [b'Y', b'V', b'1', b'2'];
+pub const DRM_FORMAT_YUV422: [u8; 4] = [b'Y', b'U', b'1', b'6'];
+pub const DRM_FORMAT_YVU422: [u8; 4] = [b'Y', b'V', b'1', b'6'];
+pub const DRM_FORMAT_YUV444: [u8; 4] = [b'Y', b'U', b'2', b'4'];
+pub const DRM_FORMAT_YVU444: [u8; 4] = [b'Y', b'V', b'2', b'4'];
diff --git a/gpu_buffer/src/lib.rs b/gpu_buffer/src/lib.rs
index 449ab53..a75159e 100644
--- a/gpu_buffer/src/lib.rs
+++ b/gpu_buffer/src/lib.rs
@@ -36,6 +36,7 @@ extern crate sys_util;
 
 pub mod rendernode;
 mod raw;
+mod drm_formats;
 
 use std::os::raw::c_void;
 use std::fmt;
@@ -49,6 +50,7 @@ use std::result::Result;
 use data_model::VolatileSlice;
 
 use raw::*;
+use drm_formats::*;
 
 const MAP_FAILED: *mut c_void = (-1isize as *mut _);
 
@@ -78,6 +80,78 @@ impl Format {
         let f = self.0;
         [f as u8, (f >> 8) as u8, (f >> 16) as u8, (f >> 24) as u8]
     }
+
+    /// Returns the number of bytes per pixel for the given plane, suitable for making copies
+    /// to/from the plane.
+    pub fn bytes_per_pixel(&self, plane: usize) -> Option<usize> {
+        let b = self.to_bytes();
+
+        // NV12 and NV21 have 2 planes with 1 byte per pixel.
+        if (b == DRM_FORMAT_NV12 || b == DRM_FORMAT_NV21) && plane < 2 {
+            return Some(1);
+        }
+
+        // YVU420 has 3 planes, all with the same 1 byte per pixel.
+        if b == DRM_FORMAT_YVU420 && plane < 3 {
+            return Some(1);
+        }
+
+        if plane != 0 {
+            return None;
+        }
+
+        let bpp = match self.to_bytes() {
+            DRM_FORMAT_BGR233 => 1,
+            DRM_FORMAT_C8 => 1,
+            DRM_FORMAT_R8 => 1,
+            DRM_FORMAT_RGB332 => 1,
+            DRM_FORMAT_ABGR1555 => 2,
+            DRM_FORMAT_ABGR4444 => 2,
+            DRM_FORMAT_ARGB1555 => 2,
+            DRM_FORMAT_ARGB4444 => 2,
+            DRM_FORMAT_BGR565 => 2,
+            DRM_FORMAT_BGRA4444 => 2,
+            DRM_FORMAT_BGRA5551 => 2,
+            DRM_FORMAT_BGRX4444 => 2,
+            DRM_FORMAT_BGRX5551 => 2,
+            DRM_FORMAT_GR88 => 2,
+            DRM_FORMAT_RG88 => 2,
+            DRM_FORMAT_RGB565 => 2,
+            DRM_FORMAT_RGBA4444 => 2,
+            DRM_FORMAT_RGBA5551 => 2,
+            DRM_FORMAT_RGBX4444 => 2,
+            DRM_FORMAT_RGBX5551 => 2,
+            DRM_FORMAT_UYVY => 2,
+            DRM_FORMAT_VYUY => 2,
+            DRM_FORMAT_XBGR1555 => 2,
+            DRM_FORMAT_XBGR4444 => 2,
+            DRM_FORMAT_XRGB1555 => 2,
+            DRM_FORMAT_XRGB4444 => 2,
+            DRM_FORMAT_YUYV => 2,
+            DRM_FORMAT_YVYU => 2,
+            DRM_FORMAT_BGR888 => 3,
+            DRM_FORMAT_RGB888 => 3,
+            DRM_FORMAT_ABGR2101010 => 4,
+            DRM_FORMAT_ABGR8888 => 4,
+            DRM_FORMAT_ARGB2101010 => 4,
+            DRM_FORMAT_ARGB8888 => 4,
+            DRM_FORMAT_AYUV => 4,
+            DRM_FORMAT_BGRA1010102 => 4,
+            DRM_FORMAT_BGRA8888 => 4,
+            DRM_FORMAT_BGRX1010102 => 4,
+            DRM_FORMAT_BGRX8888 => 4,
+            DRM_FORMAT_RGBA1010102 => 4,
+            DRM_FORMAT_RGBA8888 => 4,
+            DRM_FORMAT_RGBX1010102 => 4,
+            DRM_FORMAT_RGBX8888 => 4,
+            DRM_FORMAT_XBGR2101010 => 4,
+            DRM_FORMAT_XBGR8888 => 4,
+            DRM_FORMAT_XRGB2101010 => 4,
+            DRM_FORMAT_XRGB8888 => 4,
+            _ => return None,
+        };
+        return Some(bpp);
+    }
 }
 
 impl From<u32> for Format {
@@ -507,6 +581,28 @@ mod tests {
     }
 
     #[test]
+    fn format_bytes_per_pixel() {
+        let f = Format::new(b'X', b'R', b'2', b'4');
+        assert_eq!(f.bytes_per_pixel(0), Some(4));
+        assert_eq!(f.bytes_per_pixel(1), None);
+        let f = Format::new(b'N', b'V', b'1', b'2');
+        assert_eq!(f.bytes_per_pixel(0), Some(1));
+        assert_eq!(f.bytes_per_pixel(1), Some(2));
+        assert_eq!(f.bytes_per_pixel(2), None);
+        let f = Format::new(b'R', b'8', b' ', b' ');
+        assert_eq!(f.bytes_per_pixel(0), Some(1));
+        assert_eq!(f.bytes_per_pixel(1), None);
+        let f = Format::new(b'B', b'G', b'2', b'4');
+        assert_eq!(f.bytes_per_pixel(0), Some(3));
+        assert_eq!(f.bytes_per_pixel(1), None);
+        let f = Format::new(b'G', b'R', b'8', b'8');
+        assert_eq!(f.bytes_per_pixel(0), Some(2));
+        assert_eq!(f.bytes_per_pixel(1), None);
+        let f = Format::new(b'Z', b'A', b'C', b'H');
+        assert_eq!(f.bytes_per_pixel(0), None);
+    }
+
+    #[test]
     #[ignore] // no access to /dev/dri
     fn open_device() {
         let drm_card = File::open("/dev/dri/card0").expect("failed to open card");