From 507d749384846c2302c4749729ad2cc156d8cc12 Mon Sep 17 00:00:00 2001
From: Joursoir <chat@joursoir.net>
Date: Sun, 27 Mar 2022 10:14:27 +0300
Subject: main: make ParseGraphicsPixelFormat()

---
 UefiMonitorTest/UefiMonitorTest.c | 45 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

(limited to 'UefiMonitorTest')

diff --git a/UefiMonitorTest/UefiMonitorTest.c b/UefiMonitorTest/UefiMonitorTest.c
index 084a8b9..f84c00a 100644
--- a/UefiMonitorTest/UefiMonitorTest.c
+++ b/UefiMonitorTest/UefiMonitorTest.c
@@ -20,6 +20,51 @@ CONST EFI_PIXEL_BITMASK mBgrPixelMasks = {
   0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000
 };
 
+STATIC
+VOID
+ParseGraphicsPixelFormat (
+  IN CONST EFI_PIXEL_BITMASK  *BitMask,
+  OUT UINT32                  *PixelWidth,
+  OUT INT8                    *PixelShl,
+  OUT INT8                    *PixelShr
+  )
+{
+  UINT8   Index;
+  UINT32  *Masks;
+  UINT32  MergedMasks;
+
+  MergedMasks = 0;
+  Masks       = (UINT32 *)BitMask;
+  for (Index = 0; Index < 3; Index++) {
+    ASSERT ((MergedMasks & Masks[Index]) == 0);
+
+    PixelShl[Index] = (INT8)HighBitSet32 (Masks[Index]) - 23 + (Index * 8);
+    if (PixelShl[Index] < 0) {
+      PixelShr[Index] = -PixelShl[Index];
+      PixelShl[Index] = 0;
+    } else {
+      PixelShr[Index] = 0;
+    }
+
+    DEBUG ((
+      DEBUG_INFO,
+      "Index %d: shl:%d shr:%d mask:%08x\n",
+      Index,
+      PixelShl[Index],
+      PixelShr[Index],
+      Masks[Index]
+      ));
+
+    MergedMasks = (UINT32)(MergedMasks | Masks[Index]);
+  }
+
+  MergedMasks = (UINT32)(MergedMasks | Masks[3]);
+
+  ASSERT (MergedMasks != 0);
+  *PixelWidth = (UINT32)((HighBitSet32 (MergedMasks) + 7) / 8);
+  DEBUG ((DEBUG_INFO, "Bytes per pixel: %d\n", *PixelWidth));
+}
+
 STATIC
 VOID
 PrepareGraphicsInfo (
-- 
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