Modified the calculation of where to draw parallaxes to be more like the

one in Broken Sword II. At least the first room appears to behave like the
original now. (Except for a masking bug, which is almost certainly
unrelated to parallaxes.)

svn-id: r11781

1 files changed, 15 insertions, 4 deletions

diff --git a/sword1/screen.cpp b/sword1/screen.cpp
index 80b61dc5ce..7d7f08a6eb 100644
--- a/sword1/screen.cpp
+++ b/sword1/screen.cpp
@@ -441,10 +441,21 @@ void SwordScreen::blitBlockClear(uint16 x, uint16 y, uint8 *data) {
 void SwordScreen::renderParallax(uint8 *data) {
 	ParallaxHeader *header = (ParallaxHeader*)data;
 	assert((FROM_LE_16(header->sizeX) >= SCREEN_WIDTH) && (FROM_LE_16(header->sizeY) >= SCREEN_DEPTH));
-	double scrlfx =  FROM_LE_16(header->sizeX) / ((double)_scrnSizeX );
-	double scrlfy = FROM_LE_16(header->sizeY) / ((double)_scrnSizeY );
-	uint16 scrlX = (uint16)(SwordLogic::_scriptVars[SCROLL_OFFSET_X] * scrlfx);
-	uint16 scrlY = (uint16)(SwordLogic::_scriptVars[SCROLL_OFFSET_Y] * scrlfy);
+
+	double scrlfx, scrlfy;
+	uint16 scrlX, scrlY;
+
+	if (_scrnSizeX != SCREEN_WIDTH) {
+		scrlfx = (FROM_LE_16(header->sizeX) - SCREEN_WIDTH) / ((double)(_scrnSizeX - SCREEN_WIDTH));
+		scrlX = (uint16)(SwordLogic::_scriptVars[SCROLL_OFFSET_X] * scrlfx);
+	} else
+		scrlX = 0;
+
+	if (_scrnSizeY != SCREEN_DEPTH) {
+		scrlfy = (FROM_LE_16(header->sizeY) - SCREEN_DEPTH) / ((double)(_scrnSizeY - SCREEN_DEPTH));
+		scrlY = (uint16)(SwordLogic::_scriptVars[SCROLL_OFFSET_Y] * scrlfy);
+	} else
+		scrlY = 0;
 
 	for (uint16 cnty = 0; cnty < SCREEN_DEPTH; cnty++) {
 		uint8 *src = data + READ_LE_UINT32(header->lineIndexes + cnty + scrlY);