Reduce CLX frame header size to 6

diasurgical · Oct 12, 2024 · 5f26001 · 5f26001
1 parent 64c0629
commit 5f26001
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Showing 5 changed files with 26 additions and 20 deletions.
diff --git a/src/internal/cel2clx.cpp b/src/internal/cel2clx.cpp
@@ -8,6 +8,7 @@
 #include <memory>
 #include <vector>
 
+#include <dvl_gfx_common.hpp>
 #include <dvl_gfx_endian.hpp>
 
 #include "clx_encode.hpp"
@@ -83,9 +84,8 @@ std::optional<IoError> CelToClx(const uint8_t *data, size_t size,
 
 			// CLX frame header.
 			const size_t frameHeaderPos = clxData.size();
-			constexpr size_t FrameHeaderSize = 10;
-			clxData.resize(clxData.size() + FrameHeaderSize);
-			WriteLE16(&clxData[frameHeaderPos], FrameHeaderSize);
+			clxData.resize(clxData.size() + ClxFrameHeaderSize);
+			WriteLE16(&clxData[frameHeaderPos], ClxFrameHeaderSize);
 			WriteLE16(&clxData[frameHeaderPos + 2], frameWidth);
 
 			unsigned transparentRunWidth = 0;
@@ -109,7 +109,6 @@ std::optional<IoError> CelToClx(const uint8_t *data, size_t size,
 			}
 			AppendClxTransparentRun(transparentRunWidth, clxData);
 			WriteLE16(&clxData[frameHeaderPos + 4], frameHeight);
-			memset(&clxData[frameHeaderPos + 6], 0, 4);
 		}
 
 		WriteLE32(&clxData[clxDataOffset + 4 * (1 + static_cast<size_t>(numFrames))], static_cast<uint32_t>(clxData.size() - clxDataOffset));

diff --git a/src/internal/cl22clx.cpp b/src/internal/cl22clx.cpp
@@ -16,8 +16,6 @@ namespace dvl_gfx {
 
 namespace {
 
-constexpr size_t FrameHeaderSize = 10;
-
 constexpr bool IsCl2Opaque(uint8_t control)
 {
 	constexpr uint8_t Cl2OpaqueMin = 0x80;
@@ -122,14 +120,14 @@ std::optional<IoError> Cl2ToClx(const uint8_t *data, size_t size,
 			const uint16_t frameWidth = numWidths == 1 ? *widths : widths[frame - 1];
 
 			const size_t frameHeaderPos = clxData.size();
-			clxData.resize(clxData.size() + FrameHeaderSize);
-			WriteLE16(&clxData[frameHeaderPos], FrameHeaderSize);
+			clxData.resize(clxData.size() + ClxFrameHeaderSize);
+			WriteLE16(&clxData[frameHeaderPos], ClxFrameHeaderSize);
 			WriteLE16(&clxData[frameHeaderPos + 2], frameWidth);
 
 			unsigned transparentRunWidth = 0;
 			int_fast16_t xOffset = 0;
 			size_t frameHeight = 0;
-			const uint8_t *src = frameBegin + FrameHeaderSize;
+			const uint8_t *src = frameBegin + LoadLE16(frameBegin);
 			while (src != frameEnd) {
 				auto remainingWidth = static_cast<int_fast16_t>(frameWidth) - xOffset;
 				while (remainingWidth > 0) {
@@ -175,7 +173,6 @@ std::optional<IoError> Cl2ToClx(const uint8_t *data, size_t size,
 			AppendClxTransparentRun(transparentRunWidth, clxData);
 
 			WriteLE16(&clxData[frameHeaderPos + 4], frameHeight);
-			memset(&clxData[frameHeaderPos + 6], 0, 4);
 		}
 
 		WriteLE32(&clxData[clxDataOffset + 4 * (1 + static_cast<size_t>(numFrames))], static_cast<uint32_t>(clxData.size() - clxDataOffset));
@@ -211,7 +208,7 @@ std::optional<IoError> Cl2ToClxNoReencode(uint8_t *data, size_t size,
 			uint8_t *frameBegin = frameEnd;
 			frameEnd = &groupBegin[LoadLE32(&groupBegin[4 * (frame + 1)])];
 
-			const size_t numPixels = CountCl2FramePixels(frameBegin + FrameHeaderSize, frameEnd);
+			const size_t numPixels = CountCl2FramePixels(frameBegin + LoadLE16(frameBegin), frameEnd);
 
 			const uint16_t frameWidth = numWidths == 1 ? *widths : widths[frame - 1];
 			const uint16_t frameHeight = numPixels / frameWidth;

diff --git a/src/internal/pcx2clx.cpp b/src/internal/pcx2clx.cpp
@@ -3,6 +3,7 @@
 #include <array>
 #include <cassert>
 #include <cerrno>
+#include <cstdint>
 #include <cstring>
 #include <filesystem>
 #include <fstream>
@@ -65,18 +66,16 @@ std::optional<IoError> PcxToClx(const uint8_t *data, size_t size,
 		// 3. Height
 		// 4..5. Unused (0)
 		const size_t frameHeaderPos = clxData.size();
-		constexpr size_t FrameHeaderSize = 10;
-		clxData.resize(clxData.size() + FrameHeaderSize);
+		clxData.resize(clxData.size() + ClxFrameHeaderSize);
 
 		// Frame header:
 		const uint16_t frameWidth = cropWidths.empty()
-		    ? width
+		    ? static_cast<uint16_t>(width)
 		    : cropWidths[std::min<size_t>(cropWidths.size(), frame) - 1];
 
-		WriteLE16(&clxData[frameHeaderPos], FrameHeaderSize);
+		WriteLE16(&clxData[frameHeaderPos], ClxFrameHeaderSize);
 		WriteLE16(&clxData[frameHeaderPos + 2], static_cast<uint16_t>(frameWidth));
 		WriteLE16(&clxData[frameHeaderPos + 4], static_cast<uint16_t>(frameHeight));
-		memset(&clxData[frameHeaderPos + 6], 0, 4);
 
 		for (unsigned j = 0; j < frameHeight; ++j) {
 			uint8_t *buffer = &frameBuffer[static_cast<size_t>(j) * width];

diff --git a/src/internal/pixels2clx.cpp b/src/internal/pixels2clx.cpp
@@ -5,6 +5,7 @@
 #include <string>
 #include <vector>
 
+#include <dvl_gfx_common.hpp>
 #include <dvl_gfx_endian.hpp>
 
 #include "clx_encode.hpp"
@@ -33,14 +34,12 @@ void Pixels2Clx(
 		// 3. Height
 		// 4..5. Unused (0)
 		const size_t frameHeaderPos = clxData.size();
-		constexpr size_t FrameHeaderSize = 10;
-		clxData.resize(clxData.size() + FrameHeaderSize);
+		clxData.resize(clxData.size() + ClxFrameHeaderSize);
 
 		// Frame header:
-		WriteLE16(&clxData[frameHeaderPos], FrameHeaderSize);
+		WriteLE16(&clxData[frameHeaderPos], ClxFrameHeaderSize);
 		WriteLE16(&clxData[frameHeaderPos + 2], static_cast<uint16_t>(width));
 		WriteLE16(&clxData[frameHeaderPos + 4], static_cast<uint16_t>(frameHeight));
-		memset(&clxData[frameHeaderPos + 6], 0, 4);
 
 		const uint8_t *frameBuffer = &pixels[static_cast<size_t>((frame - 1) * pitch * frameHeight)];
 		unsigned transparentRunWidth = 0;

diff --git a/src/public/include/dvl_gfx_common.hpp b/src/public/include/dvl_gfx_common.hpp
@@ -1,6 +1,7 @@
 #ifndef DVL_GFX_COMMON_H_
 #define DVL_GFX_COMMON_H_
 
+#include <cstddef>
 #include <cstdint>
 
 #include <string>
@@ -16,5 +17,16 @@ struct Size {
 	uint32_t height;
 };
 
+/**
+ * CLX frame header is 6 bytes:
+ *
+ *  Bytes |   Type   | Value
+ * :-----:|:--------:|-------------
+ *  0..2  | uint16_t | header size
+ *  2..4  | uint16_t | width
+ *  4..6  | uint16_t | height
+ */
+constexpr size_t ClxFrameHeaderSize = 6;
+
 } // namespace dvl_gfx
 #endif // DVL_GFX_COMMON_H_