Patch #757827: Aspect-ratio correction

svn-id: r8605

5 files changed, 143 insertions, 31 deletions

diff --git a/common/gameDetector.cpp b/common/gameDetector.cpp
index 3cd1a742cb..a4841ed72b 100644
--- a/common/gameDetector.cpp
+++ b/common/gameDetector.cpp
@@ -50,38 +50,39 @@ static const char USAGE_STRING[] =
 	"Syntax:\n"
 	"\tscummvm [-v] [-d[<num>]] [-n] [-b<num>] [-t<num>] [-s<num>] [-p<path>] [-m<num>] [-f] game\n"
 	"Flags:\n"
-	"\t-p<path>      - look for game in <path>\n"
-	"\t-x[<num>]     - load this savegame (default: 0 - autosave)\n"
-	"\t-f            - fullscreen mode\n"
-	"\t-g<mode>      - graphics mode (normal,2x,3x,2xsai,super2xsai,supereagle,advmame2x,advmame3x,tv2x,dotmatrix)\n"
-	"\t-e<mode>      - set music engine (see README for details)\n"
-	"\t-a            - specify game is amiga version\n"
-	"\t-q<lang>      - specify language (en,de,fr,it,pt,es,jp,zh,kr,hb)\n"
+	"\t-p<path>       - look for game in <path>\n"
+	"\t-x[<num>]      - load this savegame (default: 0 - autosave)\n"
+	"\t-f             - fullscreen mode\n"
+	"\t-g<mode>       - graphics mode (normal,2x,3x,2xsai,super2xsai,supereagle,advmame2x,advmame3x,tv2x,dotmatrix)\n"
+	"\t-e<mode>       - set music engine (see README for details)\n"
+	"\t-a             - specify game is amiga version\n"
+	"\t-q<lang>       - specify language (en,de,fr,it,pt,es,jp,zh,kr,hb)\n"
 	"\n"
-	"\t-c<num>       - use cdrom <num> for cd audio\n"
-	"\t-m<num>       - set music volume to <num> (0-255)\n"
-	"\t-o<num>       - set master volume to <num> (0-255)\n"
-	"\t-s<num>       - set sfx volume to <num> (0-255)\n"
-	"\t-t<num>       - set music tempo (50-200, default 100%%)\n"
+	"\t-c<num>        - use cdrom <num> for cd audio\n"
+	"\t-m<num>        - set music volume to <num> (0-255)\n"
+	"\t-o<num>        - set master volume to <num> (0-255)\n"
+	"\t-s<num>        - set sfx volume to <num> (0-255)\n"
+	"\t-t<num>        - set music tempo (50-200, default 100%%)\n"
 	"\n"
-	"\t-n            - no subtitles for speech\n"
-	"\t-y            - set text speed (default: 60)\n"
+	"\t-n             - no subtitles for speech\n"
+	"\t-y             - set text speed (default: 60)\n"
 	"\n"
-	"\t-l<file>      - load config file instead of default\n"
+	"\t-l<file>       - load config file instead of default\n"
 #if defined(UNIX)
-	"\t-w[<file>]    - write to config file [~/.scummvmrc]\n"
+	"\t-w[<file>]     - write to config file [~/.scummvmrc]\n"
 #else
-	"\t-w[<file>]    - write to config file [scummvm.ini]\n"
+	"\t-w[<file>]     - write to config file [scummvm.ini]\n"
 #endif
-	"\t-v            - show version info and exit\n"
-	"\t-z            - display list of games\n"
+	"\t-v             - show version info and exit\n"
+	"\t-z             - display list of games\n"
 	"\n"
-	"\t-b<num>       - start in room <num>\n"
-	"\t-d[<num>]     - enable debug output (debug level [1])\n"
-	"\t-u            - dump scripts\n"
+	"\t-b<num>        - start in room <num>\n"
+	"\t-d[<num>]      - enable debug output (debug level [1])\n"
+	"\t-u             - dump scripts\n"
 	"\n"
-	"\t--multi-midi  - enable combination Adlib and native MIDI\n"
-	"\t--native-mt32 - true Roland MT-32 (disable GM emulation)\n"
+	"\t--multi-midi   - enable combination Adlib and native MIDI\n"
+	"\t--native-mt32  - true Roland MT-32 (disable GM emulation)\n"
+	"\t--aspect-ratio - enable aspect ratio correction\n"
 ;
 #endif
 // This contains a pointer to a list of all supported games.
@@ -148,6 +149,7 @@ static int countVersions(const VersionSettings *v) {
 
 GameDetector::GameDetector() {
 	_fullScreen = false;
+	_aspectRatio = false;
 
 	_use_adlib = false;
 
@@ -245,6 +247,7 @@ void GameDetector::updateconfig() {
 		}
 
 	_fullScreen = g_config->getBool("fullscreen", _fullScreen);
+	_aspectRatio = g_config->getBool("aspect_ratio", _aspectRatio);
 
 	if ((val = g_config->get("gfx_mode")))
 		if ((_gfx_mode = parseGraphicsMode(val)) == -1) {
@@ -453,6 +456,9 @@ void GameDetector::parseCommandLine(int argc, char **argv) {
 				} else if (!strcmp (s, "native-mt32")) {
 					_native_mt32 = true;
 					g_config->setBool ("native_mt32", true);
+				} else if (!strcmp (s, "aspect-ratio")) {
+					_aspectRatio = true;
+					g_config->setBool ("aspect_ratio", true);
 				} else {
 					goto ShowHelpAndExit;
 				}
@@ -673,7 +679,7 @@ OSystem *GameDetector::createSystem() {
 	return OSystem_PALMOS_create(_gfx_mode);
 #else
 	/* SDL is the default driver for now */
-	return OSystem_SDL_create(_gfx_mode, _fullScreen);
+	return OSystem_SDL_create(_gfx_mode, _fullScreen, _aspectRatio);
 #endif
 }
 
diff --git a/common/gameDetector.h b/common/gameDetector.h
index f73f20cd56..d9e5b104a5 100644
--- a/common/gameDetector.h
+++ b/common/gameDetector.h
@@ -110,6 +110,7 @@ public:
 	const String& getGameName(void);
 	
 	bool _fullScreen;
+	bool _aspectRatio;
 
 	bool _use_adlib;
 
diff --git a/common/scaler.cpp b/common/scaler.cpp
index 1607fef214..0d952110c1 100644
--- a/common/scaler.cpp
+++ b/common/scaler.cpp
@@ -30,7 +30,9 @@ static uint32 lowPixelMask = 0x08210821;
 static uint32 qcolorMask = 0xE79CE79C;
 static uint32 qlowpixelMask = 0x18631863;
 static uint32 redblueMask = 0xF81F;
-static uint32 greenMask = 0x7E0;
+static uint32 redMask = 0xF800;
+static uint32 greenMask = 0x07E0;
+static uint32 blueMask = 0x001F;
 
 static const uint16 dotmatrix_565[16] = {
 	0x01E0, 0x0007, 0x3800, 0x0000,
@@ -53,7 +55,9 @@ int Init_2xSaI(uint32 BitFormat) {
 		qcolorMask = 0xE79CE79C;
 		qlowpixelMask = 0x18631863;
 		redblueMask = 0xF81F;
-		greenMask = 0x7E0;
+		redMask = 0xF800;
+		greenMask = 0x07E0;
+		blueMask = 0x001F;
 		dotmatrix = dotmatrix_565;
 	} else if (BitFormat == 555) {
 		colorMask = 0x7BDE7BDE;
@@ -61,7 +65,9 @@ int Init_2xSaI(uint32 BitFormat) {
 		qcolorMask = 0x739C739C;
 		qlowpixelMask = 0x0C630C63;
 		redblueMask = 0x7C1F;
-		greenMask = 0x3E0;
+		redMask = 0x7C00;
+		greenMask = 0x03E0;
+		blueMask = 0x001F;
 		dotmatrix = dotmatrix_555;
 	} else {
 		return 0;
@@ -634,3 +640,93 @@ void DotMatrix(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPi
 		q += nextlineDst << 1;
 	}
 }
+
+
+static inline uint32 interpolate5(uint16 A, uint16 B, int scale) {
+	uint16 r = ((A & redMask) * scale + (B & redMask) * (5 - scale)) / 5;
+	uint16 g = ((A & greenMask) * scale + (B & greenMask) * (5 - scale)) / 5;
+	uint16 b = ((A & blueMask) * scale + (B & blueMask) * (5 - scale)) / 5;
+
+	return (r & redMask) | (g & greenMask) | (b & blueMask);
+}
+
+static inline void interpolate5Line(uint16 *dst, const uint16 *srcA, const uint16 *srcB, int scale, int width) {
+#if 1
+	// Accurate but slightly slower code
+	while (width--) {
+		*dst++ = interpolate5(*srcA++, *srcB++, scale);
+	}
+#else
+	// Not fully accurate, but a bit faster
+	width /= 2;
+	const uint32 *sA = (const uint32 *)srcA;
+	const uint32 *sB = (const uint32 *)srcB;
+	uint32 *d = (uint32 *)dst;
+	if (scale == 1) {
+		while (width--) {
+			uint32 B = *sB++;
+			*d++ = Q_INTERPOLATE(*sA++, B, B, B);
+		}
+	} else {
+		while (width--) {
+			*d++ = INTERPOLATE(*sA++, *sB++);
+		}
+	}
+#endif
+}
+
+/**
+ * Stretch a 16bpp image vertically by factor 1.2. Used to correct the
+ * aspect-ratio in games using 320x200 pixel graphics with non-qudratic
+ * pixels. Applying this method effectively turns that into 320x240, which
+ * provides the correct aspect-ratio on modern displays.
+ *
+ * The image would normally have occupied y coordinates origSrcY through
+ * origSrcY + height - 1.
+ *
+ * However, we have already placed it at srcY - the aspect-corrected y
+ * coordinate - to allow in-place stretching.
+ *
+ * Therefore, the source image now occupies Y coordinates srcY through
+ * srcY + height - 1, and it should be stretched to Y coordinates srcY
+ * through real2Aspect(srcY + height - 1).
+ */
+int stretch200To240(uint8 *buf, uint32 pitch, int width, int height, int srcX, int srcY, int origSrcY) {
+	int maxDstY = real2Aspect(origSrcY + height - 1);
+	int off = srcY - origSrcY;
+	int y;
+
+	uint8 *dstPtr = buf + srcX * 2 + maxDstY * pitch;
+
+	for (y = maxDstY; y >= srcY; y--) {
+		uint8 *srcPtr = buf + srcX * 2 + (aspect2Real(y) + off) * pitch;
+
+		if (srcPtr == dstPtr)
+			break;
+		
+#if 0
+		// Don't use bilinear filtering, rather just duplicate pixel lines:
+		// a little bit faster, but looks ugly
+		memcpy(dstPtr, srcPtr, width * 2);
+#else
+		// Bilinear filter
+		switch (y % 6) {
+		case 0:
+		case 5:
+			memcpy(dstPtr, srcPtr, width * 2);
+			break;
+		case 1:
+		case 4:
+			interpolate5Line((uint16 *)dstPtr, (uint16 *)(srcPtr - pitch), (uint16 *)srcPtr, 1, width);
+			break;
+		case 2:
+		case 3:
+			interpolate5Line((uint16 *)dstPtr, (uint16 *)(srcPtr - pitch), (uint16 *)srcPtr, 2, width);
+			break;
+		}
+#endif
+		dstPtr -= pitch;
+	}
+
+	return 1 + maxDstY - srcY;
+}
diff --git a/common/scaler.h b/common/scaler.h
index e3246587c9..b8000ddccd 100644
--- a/common/scaler.h
+++ b/common/scaler.h
@@ -41,6 +41,15 @@ DECLARE_SCALER(Normal3x);
 DECLARE_SCALER(TV2x);
 DECLARE_SCALER(DotMatrix);
 
+FORCEINLINE int real2Aspect(int y) {
+	return y + (y + 1) / 5;
+}
+
+FORCEINLINE int aspect2Real(int y) {
+	return (y * 5 + 3) / 6;
+}
+
+extern int stretch200To240(uint8 *buf, uint32 pitch, int width, int height, int srcX, int srcY, int origSrcY);
 
 enum {
 	GFX_NORMAL = 0,
@@ -54,7 +63,6 @@ enum {
 	GFX_TV2X = 8,
 	GFX_DOTMATRIX = 9,
 
-	GFX_ASPECTRATIO = 11, // OpenGL backend
 	GFX_BILINEAR = 12,    // OpenGL backend
 	
 	GFX_FLIPPING = 100,	// Palmos
diff --git a/common/system.h b/common/system.h
index 68408a6a13..32e55e4879 100644
--- a/common/system.h
+++ b/common/system.h
@@ -94,7 +94,8 @@ public:
 		PROP_GET_SAMPLE_RATE = 6,
 		PROP_GET_FULLSCREEN = 7,
 		PROP_GET_FMOPL_ENV_BITS = 8,
-		PROP_GET_FMOPL_EG_ENT = 9
+		PROP_GET_FMOPL_EG_ENT = 9,
+		PROP_TOGGLE_ASPECT_RATIO = 10
 	};
 	union Property {
 		const char *caption;
@@ -363,7 +364,7 @@ public:
 /* Factory functions. This means we don't have to include the headers for
  * all backends.
  */
-extern OSystem *OSystem_SDL_create(int gfx_driver, bool full_screen);
+extern OSystem *OSystem_SDL_create(int gfx_driver, bool full_screen, bool aspect_ratio);
 extern OSystem *OSystem_NULL_create();
 extern OSystem *OSystem_MorphOS_create(int game_id, int gfx_driver, bool full_screen);
 extern OSystem *OSystem_Dreamcast_create();