From 014c81190342197fe28d072b52fd1176b76f9447 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Thu, 14 Dec 2023 15:02:13 +0100
Subject: [PATCH] Add `PixelFormatExtensions::ComputeBlockSize`

---
 .../Engine/Graphics/PixelFormatExtensions.cpp | 31 +++++++++++++++++++
 .../Engine/Graphics/PixelFormatExtensions.h   |  7 +++++
 2 files changed, 38 insertions(+)

diff --git a/Source/Engine/Graphics/PixelFormatExtensions.cpp b/Source/Engine/Graphics/PixelFormatExtensions.cpp
index 991844b22..f79530337 100644
--- a/Source/Engine/Graphics/PixelFormatExtensions.cpp
+++ b/Source/Engine/Graphics/PixelFormatExtensions.cpp
@@ -660,6 +660,37 @@ int PixelFormatExtensions::ComputeComponentsCount(const PixelFormat format)
     }
 }
 
+int32 PixelFormatExtensions::ComputeBlockSize(PixelFormat format)
+{
+    switch (format)
+    {
+    case PixelFormat::BC1_Typeless:
+    case PixelFormat::BC1_UNorm:
+    case PixelFormat::BC1_UNorm_sRGB:
+    case PixelFormat::BC2_Typeless:
+    case PixelFormat::BC2_UNorm:
+    case PixelFormat::BC2_UNorm_sRGB:
+    case PixelFormat::BC3_Typeless:
+    case PixelFormat::BC3_UNorm:
+    case PixelFormat::BC3_UNorm_sRGB:
+    case PixelFormat::BC4_Typeless:
+    case PixelFormat::BC4_UNorm:
+    case PixelFormat::BC4_SNorm:
+    case PixelFormat::BC5_Typeless:
+    case PixelFormat::BC5_UNorm:
+    case PixelFormat::BC5_SNorm:
+    case PixelFormat::BC6H_Typeless:
+    case PixelFormat::BC6H_Uf16:
+    case PixelFormat::BC6H_Sf16:
+    case PixelFormat::BC7_Typeless:
+    case PixelFormat::BC7_UNorm:
+    case PixelFormat::BC7_UNorm_sRGB:
+        return 4;
+    default:
+        return 1;
+    }
+}
+
 PixelFormat PixelFormatExtensions::TosRGB(const PixelFormat format)
 {
     switch (format)
diff --git a/Source/Engine/Graphics/PixelFormatExtensions.h b/Source/Engine/Graphics/PixelFormatExtensions.h
index 604bcb2c3..362e5634f 100644
--- a/Source/Engine/Graphics/PixelFormatExtensions.h
+++ b/Source/Engine/Graphics/PixelFormatExtensions.h
@@ -173,6 +173,13 @@ public:
     /// <returns>The components count.</returns>
     API_FUNCTION() static int ComputeComponentsCount(PixelFormat format);
 
+    /// <summary>
+    /// Computes the amount of pixels per-axis stored in the a single block of the format (eg. 4 for BC-family). Returns 1 for uncompressed formats.
+    /// </summary>
+    /// <param name="format">The <see cref="PixelFormat"/>.</param>
+    /// <returns>The block pixels count.</returns>
+    API_FUNCTION() static int32 ComputeBlockSize(PixelFormat format);
+
     /// <summary>
     /// Finds the equivalent sRGB format to the provided format.
     /// </summary>