fix: scene glitches

Render scene to scratch buffer, this fixes leftover garbage when using
background surface directly. Fill last line correctly, this fixes
garbage on bottom of the original intro.

Fix 23

src/io/file.cpp

@@ -311,49 +311,54 @@ unsigned char * File::loadBlock (int length) {
  * Load a block of RLE compressed data from the file.
  *
  * @param length The length of the uncompressed block
+ * @param checkSize Whether or not the RLE block is terminated
  *
  * @return Buffer containing the uncompressed data
  */
-unsigned char* File::loadRLE (int length) {
+unsigned char* File::loadRLE (int length, bool checkSize) {
+	int start = 0, size = 0;
 
-	// Determine the offset that follows the block
-	int next = fgetc(file);
-	next += fgetc(file) << 8;
-	next += ftell(file);
+	if (checkSize) {
+		// Determine the offset that follows the block
+		size = loadShort();
+		start = tell();
+	}
 
 	unsigned char* buffer = new unsigned char[length];
 
 	int pos = 0;
-
 	while (pos < length) {
 
-		int rle = fgetc(file);
+		int rle = loadChar();
 
 		if (rle & 128) {
 
-			int byte = fgetc(file);
-
-			for (int i = 0; i < (rle & 127); i++) {
+			int byte = loadChar();
+			int amount = rle & 127;
 
-				buffer[pos++] = byte;
-				if (pos >= length) break;
+			if (pos + amount >= length) break;
 
-			}
+			memset(buffer + pos, byte, amount);
+			pos += amount;
 
 		} else if (rle) {
 
-			for (int i = 0; i < rle; i++) {
+			if (pos + rle >= length) break;
 
-				buffer[pos++] = fgetc(file);
-				if (pos >= length) break;
+			fread(buffer + pos, 1, rle, file);
 
-			}
+			pos += rle;
 
-		} else buffer[pos++] = fgetc(file);
+		} else buffer[pos++] = loadChar();
 
 	}
 
-	fseek(file, next, SEEK_SET);
+	if (checkSize) {
+		if (tell() != start + size)
+			LOG_DEBUG("RLE block has incorrect size: %d vs. %d", tell() - start, size);
+
+		seek(start + size, true);
+	}
 
 	return buffer;
 
@@ -478,15 +483,16 @@ char * File::loadString (int length) {
  *
  * @param width The width of the image to load
  * @param height The height of the image to load
+ * @param checkSize Whether or not the RLE block is terminated
  *
  * @return SDL surface containing the loaded image
  */
-SDL_Surface* File::loadSurface (int width, int height) {
+SDL_Surface* File::loadSurface (int width, int height, bool checkSize) {
 
 	SDL_Surface* surface;
 	unsigned char* pixels;
 
-	pixels = loadRLE(width * height);
+	pixels = loadRLE(width * height, checkSize);
 
 	surface = createSurface(pixels, width, height);
 

src/io/file.h

@@ -26,7 +26,7 @@
 
 #include <SDL.h>
 #include <stdio.h>
-
+#include <memory>
 
 // Classes
 
@@ -54,18 +54,21 @@ class File {
 		signed int         loadInt     ();
 		void               storeInt    (signed int val);
 		unsigned char*     loadBlock   (int length);
-		unsigned char*     loadRLE     (int length);
+		unsigned char*     loadRLE     (int length, bool checkSize = true);
 		void               skipRLE     ();
 		unsigned char*     loadLZ      (int compressedLength, int length);
 		char*              loadString  ();
 		char*              loadString  (int length);
-		SDL_Surface*       loadSurface (int width, int height);
+		SDL_Surface*       loadSurface (int width, int height, bool checkSize = true);
 		unsigned char*     loadPixels  (int length);
 		unsigned char*     loadPixels  (int length, int key);
 		void               loadPalette (SDL_Color* palette, bool rle = true);
 
 };
 
+using FilePtr = std::unique_ptr<File>;
+
+
 /// Directory path
 
 enum path_type {

src/jj1/save/jj1save.cpp

@@ -20,8 +20,6 @@
 #include "util.h"
 #include "io/log.h"
 
-#include <memory>
-
 /* This algorithm has been found out by CYBERDEViL by analysing the Assembly in
  * DoxBox-X. For more information see: https://codeberg.org/CYBERDEV/JJSave/
  */
@@ -78,7 +76,7 @@ static unsigned short dataOffset(unsigned short key, bool skipGarbage = false) {
 JJ1Save::JJ1Save (const char* fileName) :
 	valid(false) {
 
-	std::unique_ptr<File> file;
+	FilePtr file;
 	LOG_TRACE("Save: %s", fileName);
 
 	try {

src/jj1/scene/jj1scene.cpp

@@ -104,6 +104,7 @@ JJ1SceneAnimation::JJ1SceneAnimation  (JJ1SceneAnimation* newNext) {
 
 	next = newNext;
 	background = NULL;
+	scratch = createSurface(NULL, SW, SH);
 	lastFrame = sceneFrames = NULL;
 	frames = reverseAnimation = 0;
 	id = -1;
@@ -131,6 +132,7 @@ JJ1SceneAnimation::~JJ1SceneAnimation () {
 		}
 
 	if (background) SDL_FreeSurface(background);
+	if (scratch) SDL_FreeSurface(scratch);
 
 }
 
@@ -249,13 +251,13 @@ JJ1ScenePage::~JJ1ScenePage() {
  */
 JJ1Scene::JJ1Scene (const char * fileName) {
 
-	File *file;
+	FilePtr file;
 	nFonts = 0;
 	LOG_TRACE("Scene: %s", fileName);
 
 	try {
 
-		file = new File(fileName, PATH_TYPE_GAME);
+		file = std::make_unique<File>(fileName, PATH_TYPE_GAME);
 
 	} catch (int e) {
 
@@ -268,7 +270,7 @@ JJ1Scene::JJ1Scene (const char * fileName) {
 	animations = NULL;
 
 	file->seek(0x13, true); // Skip Digital Dimensions header
-	signed long int dataOffset = file->loadInt(); //get offset pointer to first data block
+	signed long int dataOffset = file->loadInt(); // Get offset pointer to first data block
 
 	scriptItems = file->loadShort(); // Get number of script items
 	scriptStarts = new signed long int[scriptItems];
@@ -278,8 +280,8 @@ JJ1Scene::JJ1Scene (const char * fileName) {
 
 	for (int i = 0; i < scriptItems; i++) {
 
-		scriptStarts[i] = file->loadInt();// Load offset to script
-		LOG_TRACE("scriptStart: %ld", scriptStarts[i]);
+		scriptStarts[i] = file->loadInt(); // Load offset to script
+		LOG_MAX("scriptStart: %ld", scriptStarts[i]);
 
 	}
 
@@ -291,18 +293,16 @@ JJ1Scene::JJ1Scene (const char * fileName) {
 
 	for (int i = 0; i < dataItems; i++) {
 
-		dataOffsets[i] = file->loadInt();// Load offset to script
-		LOG_TRACE("dataOffsets: %ld", dataOffsets[i]);
+		dataOffsets[i] = file->loadInt(); // Load offset to script
+		LOG_MAX("dataOffsets: %ld", dataOffsets[i]);
 
 	}
 
-	loadData(file);
-	loadScripts(file);
+	loadData(file.get());
+	loadScripts(file.get());
 
 	delete[] scriptStarts;
 	delete[] dataOffsets;
-	delete file;
-
 }
 
 
@@ -478,6 +478,7 @@ int JJ1Scene::play () {
 					dst.y = (canvasH - SH) >> 1;
 					frameDelay = 1000 / (pages[sceneIndex].animSpeed >> 8);
 					SDL_BlitSurface(animation->background, NULL, canvas, &dst);
+					SDL_BlitSurface(animation->background, NULL, animation->scratch, NULL);
 					currentFrame = animation->sceneFrames;
 					SDL_Delay(frameDelay);
 
@@ -486,19 +487,19 @@ int JJ1Scene::play () {
 			} else {
 
 				// Upload pixel data to the surface
-				if (SDL_MUSTLOCK(animation->background)) SDL_LockSurface(animation->background);
+				if (SDL_MUSTLOCK(animation->scratch)) SDL_LockSurface(animation->scratch);
 
 				switch (currentFrame->frameType) {
 
 					case ESquareAniHeader:
 
-						loadCompactedMem(currentFrame->frameSize, currentFrame->frameData, static_cast<unsigned char*>(animation->background->pixels));
+						loadCompactedMem(currentFrame->frameSize, currentFrame->frameData, static_cast<unsigned char*>(animation->scratch->pixels));
 
 						break;
 
 					case EFFAniHeader:
 
-						loadFFMem(currentFrame->frameSize, currentFrame->frameData, static_cast<unsigned char*>(animation->background->pixels));
+						loadFFMem(currentFrame->frameSize, currentFrame->frameData, static_cast<unsigned char*>(animation->scratch->pixels));
 
 						break;
 
@@ -510,11 +511,11 @@ int JJ1Scene::play () {
 
 				}
 
-				if (SDL_MUSTLOCK(animation->background)) SDL_UnlockSurface(animation->background);
+				if (SDL_MUSTLOCK(animation->scratch)) SDL_UnlockSurface(animation->scratch);
 
 				dst.x = (canvasW - SW) >> 1;
 				dst.y = (canvasH - SH) >> 1;
-				SDL_BlitSurface(animation->background, NULL, canvas, &dst);
+				SDL_BlitSurface(animation->scratch, NULL, canvas, &dst);
 
 				playSound(currentFrame->soundId);
 

src/jj1/scene/jj1scene.h

@@ -205,7 +205,8 @@ class JJ1SceneAnimation {
 		JJ1SceneFrame*      sceneFrames;
 		JJ1SceneFrame*      lastFrame;
 
-		SDL_Surface*       background;
+		SDL_Surface*        background;
+		SDL_Surface*        scratch;
 		int id;
 		int frames;
 		int reverseAnimation;