From 7184d49ccde832ae8449099f574ed038546eb2d4 Mon Sep 17 00:00:00 2001
From: Pavel Krajcevski <pavel@cs.unc.edu>
Date: Thu, 12 Sep 2013 14:41:00 -0400
Subject: [PATCH] Add unpack RGBA for our pixels

---
 PVRTCEncoder/src/Pixel.cpp      |  7 +++++++
 PVRTCEncoder/src/Pixel.h        |  1 +
 PVRTCEncoder/test/PixelTest.cpp | 19 +++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/PVRTCEncoder/src/Pixel.cpp b/PVRTCEncoder/src/Pixel.cpp
index d64b9c1..aa3d3a1 100644
--- a/PVRTCEncoder/src/Pixel.cpp
+++ b/PVRTCEncoder/src/Pixel.cpp
@@ -165,6 +165,13 @@ namespace PVRTCC {
     return r;
   }
 
+  void Pixel::UnpackRGBA(uint32 rgba) {
+    A() = ChangeBitDepth((rgba >> 24) & 0xFF, 8, m_BitDepth[0]);
+    R() = ChangeBitDepth(rgba & 0xFF, 8, m_BitDepth[1]);
+    G() = ChangeBitDepth((rgba >> 8) & 0xFF, 8, m_BitDepth[2]);
+    B() = ChangeBitDepth((rgba >> 16) & 0xFF, 8, m_BitDepth[3]);
+  }
+
   bool Pixel::operator==(const Pixel &other) const {
     uint8 depths[4];
     other.GetBitDepth(depths);
diff --git a/PVRTCEncoder/src/Pixel.h b/PVRTCEncoder/src/Pixel.h
index 692eed3..1953e09 100644
--- a/PVRTCEncoder/src/Pixel.h
+++ b/PVRTCEncoder/src/Pixel.h
@@ -110,6 +110,7 @@ class Pixel {
   // that the architecture is little-endian, so the alpha channel will end
   // up in the most-significant byte.
   uint32 PackRGBA() const;
+  void UnpackRGBA(uint32 rgba);
 
   // Tests for equality by comparing the values and the bit depths.
   bool operator==(const Pixel &) const;
diff --git a/PVRTCEncoder/test/PixelTest.cpp b/PVRTCEncoder/test/PixelTest.cpp
index afc380f..b8b4d2a 100644
--- a/PVRTCEncoder/test/PixelTest.cpp
+++ b/PVRTCEncoder/test/PixelTest.cpp
@@ -195,3 +195,22 @@ TEST(Pixel, PackRGBA) {
   uint32 val = p.PackRGBA();
   EXPECT_EQ(val, 0x87FFFF6D);
 }
+
+TEST(Pixel, UnpackRGBA) {
+  uint32 rgba = 0x4619B3FE;
+  PVRTCC::Pixel p;
+
+  p.UnpackRGBA(rgba);
+  EXPECT_EQ(p.A(), 0x46);
+  EXPECT_EQ(p.B(), 0x19);
+  EXPECT_EQ(p.G(), 0xB3);
+  EXPECT_EQ(p.R(), 0xFE);
+
+  uint8 newBitDepth[4] = { 3, 5, 2, 1 };  // A R G B
+  p.ChangeBitDepth(newBitDepth);
+
+  EXPECT_EQ(p.A(), 0x2);
+  EXPECT_EQ(p.B(), 0x0);
+  EXPECT_EQ(p.G(), 0x2);
+  EXPECT_EQ(p.R(), 0x1f);
+}