From 8afdf5affa4aa1cc312a8db37bcd1782dc226e70 Mon Sep 17 00:00:00 2001
From: Carsten Teibes <dev@f4ke.de>
Date: Tue, 24 Sep 2024 01:47:02 +0200
Subject: [PATCH] Handle metadata for 0SC images Fix 13

---
 src/io/file.cpp                | 28 +++++++---------
 src/jj1/scene/jj1sceneload.cpp | 10 +++++-
 src/util.cpp                   | 59 ++++++++++++++++++++++++++++++++++
 src/util.h                     |  1 +
 4 files changed, 80 insertions(+), 18 deletions(-)

diff --git a/src/io/file.cpp b/src/io/file.cpp
index cc8515b..e462e99 100644
--- a/src/io/file.cpp
+++ b/src/io/file.cpp
@@ -328,29 +328,23 @@ unsigned char* File::loadRLE (int length, bool checkSize) {
 
 	int pos = 0;
 	while (pos < length) {
+		unsigned char code = loadChar();
+		unsigned char amount = code & 127;
 
-		int rle = loadChar();
-
-		if (rle & 128) {
-
-			int byte = loadChar();
-			int amount = rle & 127;
+		if (code & 128) {
+			unsigned char value = loadChar();
 
 			if (pos + amount >= length) break;
 
-			memset(buffer + pos, byte, amount);
+			memset(buffer + pos, value, amount);
 			pos += amount;
+		} else if (amount) {
+			if (pos + amount >= length) break;
 
-		} else if (rle) {
-
-			if (pos + rle >= length) break;
-
-			fread(buffer + pos, 1, rle, file);
-
-			pos += rle;
-
-		} else buffer[pos++] = loadChar();
-
+			fread(buffer + pos, 1, amount, file);
+			pos += amount;
+		} else
+			buffer[pos++] = loadChar();
 	}
 
 	if (checkSize) {
diff --git a/src/jj1/scene/jj1sceneload.cpp b/src/jj1/scene/jj1sceneload.cpp
index 3cb199e..8c8cd73 100644
--- a/src/jj1/scene/jj1sceneload.cpp
+++ b/src/jj1/scene/jj1sceneload.cpp
@@ -469,7 +469,15 @@ void JJ1Scene::loadData (File *f) {
 						else height = f->loadShort(SH);
 
 						images = new JJ1SceneImage(images);
-						images->image = f->loadSurface(width, height, false);
+						if (type == 5 || type == 6) {
+							f->seek(-5, false); // account for metadata 2 + 2
+							unsigned char* pixels = unpackRLE(f->loadBlock(dataLen), dataLen, width * height + 4);
+							images->image = createSurface(pixels + 4, width, height);
+							delete[] pixels;
+						} else {
+							images->image = f->loadSurface(width, height, false);
+						}
+
 						images->id = loop;
 
 					}
diff --git a/src/util.cpp b/src/util.cpp
index d35cc31..a8db422 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -27,6 +27,7 @@
 
 #include "util.h"
 #include "io/file.h"
+#include "io/log.h"
 
 #include <string.h>
 
@@ -298,3 +299,61 @@ fixed fCos (fixed angle) {
 	return sinLut[(angle + 256) & 1023];
 
 }
+
+
+/**
+ * Unpack a block of RLE compressed data.
+ *
+ * @param data Buffer containing compressed data
+ * @param size The length of the compressed block
+ * @param outSize The length of the uncompressed block
+ *
+ * @return Buffer containing the uncompressed data
+ */
+unsigned char* unpackRLE (unsigned char* data, unsigned int size, unsigned int outSize) {
+	unsigned char* buffer = new unsigned char[outSize];
+
+	unsigned int posIn = 0, posOut = 0;
+	while (posIn < size) {
+		unsigned char code = data[posIn];
+		unsigned char amount = code & 127;
+
+		if (code & 128) { // repeat
+			unsigned char value = data[posIn+1];
+
+			if (posOut + amount >= outSize) {
+				LOG_WARN("Exceeding write buffer while RLE unpacking.");
+				break;
+			}
+
+			memset(buffer + posOut, value, amount);
+
+			posIn += 2;
+			posOut += amount;
+		} else if (amount) { // copy
+
+			if (posOut + amount >= outSize) {
+				LOG_WARN("Exceeding write buffer while RLE unpacking.");
+				break;
+			}
+
+			memcpy(buffer + posOut, data + posIn + 1, amount);
+
+			posIn += amount + 1;
+			posOut += amount;
+		} else { // end marker
+			buffer[posOut++] = data[posIn+1];
+			posIn += 2;
+
+			//LOG_MAX("End marker found while RLE unpacking.");
+			break;
+		}
+	}
+
+	if(size != posIn || outSize != posOut) {
+		LOG_DEBUG("RLE block has incorrect size: in %d/%d out %d/%d", size, posIn, outSize, posOut);
+	}
+
+	delete[] data;
+	return buffer;
+}
diff --git a/src/util.h b/src/util.h
index 29ada41..945d2a7 100644
--- a/src/util.h
+++ b/src/util.h
@@ -46,5 +46,6 @@ void               uppercaseString      (char *string);
 void               camelcaseString      (char *string);
 fixed              fSin                 (fixed angle);
 fixed              fCos                 (fixed angle);
+unsigned char*     unpackRLE            (unsigned char* data, unsigned int size, unsigned int outSize);
 
 #endif