Add AGI256-2 support (On top of already present AGI256 support).

AGI256-2 means handling 256 color views/sprites (AGI256 means handling 256 color picture resources).
The code can now handle both 16 color and 256 color views/sprites in the same game.
FIXME: Background in AGI256-2 demo may be incorrect.

svn-id: r27572

4 files changed, 21 insertions, 10 deletions

diff --git a/engines/agi/sprite.cpp b/engines/agi/sprite.cpp
index 7938d05052..3d69968075 100644
--- a/engines/agi/sprite.cpp
+++ b/engines/agi/sprite.cpp
@@ -136,7 +136,7 @@ void SpritesMgr::blitPixel(uint8 *p, uint8 *end, uint8 col, int spr, int width,
 }
 
 
-int SpritesMgr::blitCel(int x, int y, int spr, ViewCel *c) {
+int SpritesMgr::blitCel(int x, int y, int spr, ViewCel *c, bool agi256_2) {
 	uint8 *p0, *p, *q = NULL, *end;
 	int i, j, t, m, col;
 	int hidden = true;
@@ -162,8 +162,8 @@ int SpritesMgr::blitCel(int x, int y, int spr, ViewCel *c) {
 	for (i = 0; i < c->height; i++) {
 		p = p0;
 		while (*q) {
-			col = (*q & 0xf0) >> 4;
-			for (j = *q & 0x0f; j; j--, p += 1 - 2 * m) {
+			col = agi256_2 ? *q : (*q & 0xf0) >> 4; // Uses whole byte for color info with AGI256-2
+			for (j = agi256_2 ? 1 : *q & 0x0f; j; j--, p += 1 - 2 * m) { // No RLE with AGI256-2
 				if (col != t) {
 					blitPixel(p, end, col, spr, _WIDTH, &hidden);
 				}
@@ -455,7 +455,7 @@ void SpritesMgr::blitSprites(SpriteList& l) {
 		Sprite *s = *iter;
 		objsSaveArea(s);
 		debugC(8, kDebugLevelSprites, "s->v->entry = %d (prio %d)", s->v->entry, s->v->priority);
-		hidden = blitCel(s->xPos, s->yPos, s->v->priority, s->v->celData);
+		hidden = blitCel(s->xPos, s->yPos, s->v->priority, s->v->celData, s->v->viewData->agi256_2);
 		if (s->v->entry == 0) {	/* if ego, update f1 */
 			_vm->setflag(fEgoInvisible, hidden);
 		}
@@ -613,7 +613,7 @@ void SpritesMgr::addToPic(int view, int loop, int cel, int x, int y, int pri, in
 	eraseBoth();
 
 	debugC(4, kDebugLevelSprites, "blit_cel (%d, %d, %d, c)", x, y, pri);
-	blitCel(x1, y1, pri, c);
+	blitCel(x1, y1, pri, c, _vm->_game.views[view].agi256_2);
 
 	/* If margin is 0, 1, 2, or 3, the base of the cel is
 	 * surrounded with a rectangle of the corresponding priority.
@@ -691,7 +691,7 @@ void SpritesMgr::showObj(int n) {
 	s.buffer = (uint8 *)malloc(s.xSize * s.ySize);
 
 	objsSaveArea(&s);
-	blitCel(x1, y1, s.xSize, c);
+	blitCel(x1, y1, s.xSize, c, _vm->_game.views[n].agi256_2);
 	commitBlock(x1, y1, x2, y2);
 	_vm->messageBox(_vm->_game.views[n].descr);
 	objsRestoreArea(&s);
diff --git a/engines/agi/sprite.h b/engines/agi/sprite.h
index 2f703e352a..401446249b 100644
--- a/engines/agi/sprite.h
+++ b/engines/agi/sprite.h
@@ -56,7 +56,7 @@ private:
 	void *poolAlloc(int size);
 	void poolRelease(void *s);
 	void blitPixel(uint8 *p, uint8 *end, uint8 col, int spr, int width, int *hidden);
-	int blitCel(int x, int y, int spr, ViewCel *c);
+	int blitCel(int x, int y, int spr, ViewCel *c, bool agi256_2);
 	void objsSaveArea(Sprite *s);
 	void objsRestoreArea(Sprite *s);
 	
diff --git a/engines/agi/view.cpp b/engines/agi/view.cpp
index f80e4b6447..48e3ca5e3f 100644
--- a/engines/agi/view.cpp
+++ b/engines/agi/view.cpp
@@ -151,6 +151,7 @@ int AgiEngine::decodeView(int n) {
 
 	assert(v != NULL);
 
+	_game.views[n].agi256_2 = (READ_LE_UINT16(v) == 0xf00f); // Detect AGI256-2 views by their header bytes
 	_game.views[n].descr = READ_LE_UINT16(v + 3) ? (char *)(v + READ_LE_UINT16(v + 3)) : (char *)(v + 3);
 
 	/* if no loops exist, return! */
@@ -187,9 +188,18 @@ int AgiEngine::decodeView(int n) {
 
 			vc->width = *(v + cofs);
 			vc->height = *(v + cofs + 1);
-			vc->transparency = *(v + cofs + 2) & 0xf;
-			vc->mirrorLoop = (*(v + cofs + 2) >> 4) & 0x7;
-			vc->mirror = (*(v + cofs + 2) >> 7) & 0x1;
+
+			if (!_game.views[n].agi256_2) {
+				vc->transparency = *(v + cofs + 2) & 0xf;
+				vc->mirrorLoop = (*(v + cofs + 2) >> 4) & 0x7;
+				vc->mirror = (*(v + cofs + 2) >> 7) & 0x1;
+			} else {
+				// Mirroring is disabled for AGI256-2 views because
+				// AGI256-2 uses whole 8 bits for the transparency variable.
+				vc->transparency = *(v + cofs + 2);
+				vc->mirrorLoop = 0;
+				vc->mirror = 0;
+			}
 
 			/* skip over width/height/trans|mirror data */
 			cofs += 3;
diff --git a/engines/agi/view.h b/engines/agi/view.h
index a20d63793a..f2efce0ec3 100644
--- a/engines/agi/view.h
+++ b/engines/agi/view.h
@@ -51,6 +51,7 @@ struct ViewLoop {
 struct AgiView {
 	int numLoops;
 	struct ViewLoop *loop;
+	bool agi256_2;
 	char *descr;
 	uint8 *rdata;
 };