Initial commit

engines/m4/platform/draw.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "common/algorithm.h"
+#include "common/textconsole.h"
+#include "m4/platform/draw.h"
+
+namespace M4 {
+
+void RLE8Decode(const uint8 *inBuff, uint8 *outBuff, uint32 pitch) {
+	byte val, count;
+	int line = 0, numY = 0;
+	byte *destP = outBuff;
+
+	for (;;) {
+		count = *inBuff++;
+
+		if (count) {
+			// Basic run length
+			val = *inBuff++;
+			Common::fill(destP, destP + count, val);
+			destP += count;
+
+		} else {
+			count = *inBuff++;
+
+			if (count >= 3) {
+				// Block of uncompressed pixels to copy
+				Common::copy(inBuff, inBuff + count, destP);
+				inBuff += count;
+				destP += count;
+
+			} else if (!(count & 3)) {
+				// End of Line code
+				++line;
+				destP = outBuff + line * pitch;
+
+			} else if (!(count & 2)) {
+				break;
+
+			} else {
+				// Move down by X, Y amount
+				destP += *inBuff++;		// x amount
+				numY = *inBuff++;		// y amount
+				line += numY;
+				destP += numY * pitch;
+			}
+		}
+	}
+}
+
+uint8 *SkipRLE_Lines(uint32 linesToSkip, uint8 *rleData) {
+	while (linesToSkip > 0) {
+		if (*rleData) {
+			// Simple RLE sequence, so skip over count and value
+			rleData += 2;
+
+		} else if (rleData[1] >= 3) {
+			rleData += 2 + rleData[2];
+		} else {
+			rleData += 2;
+			--linesToSkip;
+		}
+	}
+
+	return rleData;
+}
+
+size_t RLE8Decode_Size(byte *src, int pitch) {
+	size_t total = 0, line = 0, y;
+	byte count;
+
+	for (;;) {
+		count = *src++;
+
+		if (count) {
+			total += count;
+			++src;
+		} else {
+			count = *src++;
+
+			if (count >= 3) {
+				// Block of uncompressed pixels to copy
+				total += count;
+				src += count;
+
+			} else if (!(count & 3)) {
+				// End of Line code
+				++line;
+				total = line * pitch;
+
+			} else if (!(count & 2)) {
+				break;
+
+			} else {
+				// Move down by X, Y amount
+				total += *src++;	// x amount
+				y = *src++;			// y amount
+				line += y;
+				total += y * pitch;
+			}
+		}
+	}
+
+	return total;
+}
+
+void RLE_Draw(Buffer *src, Buffer *dest, int32 x, int32 y) {
+	const byte *srcP = src->data;
+	byte *destData = dest->data + y * dest->w + x;
+	byte *destP = destData;
+	int destWidth = dest->w;
+	byte count, val;
+	int line = 0;
+
+	assert(x >= 0 && y >= 0 && x < dest->w && y < dest->h);
+
+	for (;;) {
+		count = *srcP++;
+
+		if (count) {
+			// Basic run length
+			val = *srcP++;
+
+			// 0 pixels are transparent, and are skipped. Otherwise, draw pixels
+			if (val != 0)
+				Common::fill(destP, destP + count, val);
+			destP += count;
+
+		} else {
+			count = *srcP++;
+
+			if (count >= 3) {
+				// Block of uncompressed pixels to copy
+				for (; count > 0; --count, ++destP) {
+					val = *srcP++;
+					if (val != 0)
+						*destP = val;
+				}
+
+			} else if (!(count & 3)) {
+				// End of line code
+				++line;
+				destP = destData + line * destWidth;
+
+			} else {
+				// Stop drawing image. Seems weird that it doesn't handle the X/Y offset
+				// form for count & 2, but the original explicitly doesn't implement it
+				break;
+			}
+		}
+	}
+
+	assert(destP <= (dest->data + dest->h * dest->stride));
+}
+
+} // namespace M4