1 files changed, 125 insertions, 0 deletions
diff --git a/engines/kyra/screen_v2.cpp b/engines/kyra/screen_v2.cpp
index 564282fb3f..13186b0167 100644
--- a/engines/kyra/screen_v2.cpp
+++ b/engines/kyra/screen_v2.cpp
@@ -29,6 +29,15 @@
 
 namespace Kyra {
 
+Screen_v2::Screen_v2(KyraEngine *vm, OSystem *system) : Screen(vm, system), _wsaFrameAnimBuffer(0) {
+	_wsaFrameAnimBuffer = new uint8[1024];
+	assert(_wsaFrameAnimBuffer);
+}
+
+Screen_v2::~Screen_v2() {
+	delete[] _wsaFrameAnimBuffer;
+}
+
 uint8 *Screen_v2::generateOverlay(const uint8 *palette, uint8 *buffer, int startColor, uint16 factor) {
 	if (!palette || !buffer)
 		return buffer;
@@ -336,5 +345,121 @@ void Screen_v2::setTextColorMap(const uint8 *cmap) {
 	setTextColor(cmap, 0, 15);
 }
 
+void Screen_v2::wsaFrameAnimationStep(int x1, int y1, int x2, int y2,
+	int w1, int h1, int w2, int h2, int srcPage, int dstPage, int dim) {
+
+	if (!(w1 || h1 || w2 || h2))
+		return;
+
+	ScreenDim cdm = *getScreenDim(dim);
+	cdm.sx <<= 3;
+	cdm.w <<= 3;
+
+	int na = 0, nb = 0, nc = w2;
+
+	if (!calcBounds(cdm.w, cdm.h, x2, y2, w2, h2, na, nb, nc))
+		return;
+
+	const uint8 *src = getPagePtr(srcPage) + y1 * 320;
+	uint8 *dst = getPagePtr(dstPage) + (y2 + cdm.sy) * 320;
+
+	int u = -1;
+
+	do {
+		int t = (nb * h1) / h2;
+		if (t != u) {
+			u = t;
+			const uint8 *s = src + (x1 + t) * 320;
+			uint8 *dt = (uint8 *)_wsaFrameAnimBuffer;
+
+			t = w2 - w1;
+			if (!t) {
+				memcpy(dt, s, w2);
+			} else if (t > 0) {
+				if (w1 == 1) {
+                    memset(dt, *s, w2);
+				} else {
+					t = ((((((w2 - w1 + 1) & 0xffff) << 8) / w1) + 0x100) & 0xffff) << 8;
+					int bp = 0;
+					for (int i = 0; i < w1; i++) {
+						int cnt = (t >> 16);
+						bp += (t & 0xffff);
+						if (bp > 0xffff) {
+							bp -= 0xffff;
+							cnt++;
+						}
+						memset(dt, *s++, cnt);
+						dt += cnt;
+					}
+				}
+			} else {
+				if (w2 == 1) {
+					*dt = *s;
+				} else {
+					t = (((((w1 - w2) & 0xffff) << 8) / w2) & 0xffff) << 8;
+					int bp = 0;
+					for (int i = 0; i < w2; i++) {
+						*dt++ = *s++;
+						bp += (t & 0xffff);
+						if (bp > 0xffff) {
+							bp -= 0xffff;
+							s++;
+						}
+						s += (t >> 16);
+					}
+				}
+			}
+		}
+		memcpy(dst + x2 + cdm.sx, _wsaFrameAnimBuffer + na, w2);
+		dst += 320;
+	} while (++nb < h2);
+}
+
+bool Screen_v2::calcBounds(int w0, int h0, int &x1, int &y1, int &w1, int &h1, int &x2, int &y2, int &w2) {
+	x2 = 0;
+	y2 = 0;
+	w2 = w1;
+
+	int t = x1 + w1;
+	if (t < 1) {
+		w1 = h1 = -1;
+	} else {
+		if (t <= x1) {
+			x2 = w1 - t;
+			w1 = t;
+			x1 = 0;
+		}
+		t = w0 - x1;
+		if (t < 1) {
+			w1 = h1 = -1;
+		} else {
+			if (t <= w1) {
+				w1 = t;
+			}
+			w2 -= w1;
+			t = h1 + y1;
+			if (t < 1) {
+				w1 = h1 = -1;
+			} else {
+				if (t <= y1) {
+					y2 = h1 - t;
+					h1 = t;
+					y1 = 0;
+				}
+                t = h0 - y1;
+				if (t < 1) {
+					w1 = h1 = -1;
+				} else {
+					if (t <= h1) {
+						h1 = t;
+					}
+				}
+			}
+		}
+	}
+
+	return (w1 == -1) ? false : true;
+}
+
 } // end of namespace Kyra