Initial commit

engines/m4/graphics/gr_surface.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 "m4/graphics/gr_surface.h"
+#include "m4/graphics/gr_sprite.h"
+
+namespace M4 {
+
+M4Surface::M4Surface(int sw, int sh) : Buffer() {
+	this->w = sw;
+	this->h = sh;
+	this->stride = sw;
+	this->encoding = NO_COMPRESS;
+	this->data = new byte[sw * sh];
+	Common::fill(this->data, this->data + sw * sh, 0);
+	_disposeAfterUse = DisposeAfterUse::YES;
+}
+
+M4Surface::M4Surface(const byte *src, int sw, int sh) {
+	this->w = sw;
+	this->h = sh;
+	this->stride = sw;
+	this->encoding = NO_COMPRESS;
+	this->data = new byte[sw * sh];
+	Common::fill(this->data, this->data + sw * sh, 0);
+	_disposeAfterUse = DisposeAfterUse::YES;
+
+	rleDraw(src);
+}
+
+M4Surface::~M4Surface() {
+	if (_disposeAfterUse == DisposeAfterUse::YES)
+		delete[] data;
+}
+
+void M4Surface::rleDraw(const byte *src, int x, int y) {
+	const byte *srcP = src;
+	byte *destData = data + y * w + x;
+	byte *destP = destData;
+	int destWidth = w;
+	byte count, val;
+	int line = 0;
+
+	assert(x >= 0 && y >= 0 && x < w && y < 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 <= (data + h * stride));
+}
+
+void M4Surface::draw(const Buffer &src, int x, int y, bool forwards,
+		const byte *depthCodes, int srcDepth, const byte *inverseColorTable,
+		const byte *palette) {
+	if ((src.encoding & 0x7f) == RLE8) {
+		// The standard case of RLE sprite drawing onto screen can directly
+		// use RLE decompression for performance
+		if (forwards && !depthCodes && !inverseColorTable && x >= 0 && y >= 0 &&
+				(x + src.w) <= this->w && (y + src.h) <= this->h) {
+			rleDraw(src.data, x, y);
+
+		} else {
+			// All other RLE drawing first decompresses the sprite, and then does
+			// the various clipping, reverse, etc. on that
+			M4Surface tmp(src.data, src.w, src.h);
+			drawInner(tmp, depthCodes, x, y, forwards, srcDepth, palette, inverseColorTable);
+		}
+	} else {
+		// Uncompressed images get passed to inner drawing
+		drawInner(src, depthCodes, x, y, forwards, srcDepth, palette, inverseColorTable);
+	}
+}
+
+void M4Surface::drawInner(const Buffer &src, const byte *depthCodes, int x, int y,
+		bool forwards, int srcDepth, const byte *palette, const byte *inverseColorTable) {
+	assert((src.encoding & 0x7f) == NO_COMPRESS);
+
+	for (int srcY = 0; srcY < src.h; ++srcY, ++y) {
+		if (y >= h)
+			// Below bottom of screen
+			break;
+		else if (y < 0)
+			// Above top of screen
+			continue;
+
+		const byte *srcP = forwards ? src.getBasePtr(0, srcY) : src.getBasePtr(src.w - 1, srcY);
+		byte *destP = getBasePtr(x, y);
+		const byte *depthP = depthCodes ? depthCodes + y * w + x : nullptr;
+		int deltaX = forwards ? 1 : -1;
+		int destX = x;
+		uint32 adjusted, total;
+
+		for (int srcX = 0; srcX < src.w; ++srcX, srcP += deltaX, ++destX) {
+			if (destX >= w)
+				// Beyond right of screen
+				break;
+
+			byte v = *srcP;
+			byte depth = depthP ? *depthP & 0xf : 0;
+			if (destX >= 0 && v != 0 && (!depthP || depth == 0 || srcDepth < depth)) {
+				if (inverseColorTable) {
+					// Handling for shadows
+					if (v != 128) {
+						const byte *palP = palette + *destP * 3;
+						uint rgb = (uint32)palP[0] | ((uint32)palP[1] << 8) |
+							((uint32)palP[2] << 16);
+						rgb >>= 2;
+
+						// Red component
+						adjusted = (rgb & 0xff) * v;
+						adjusted = MIN((uint)(adjusted >> 8), 31U);
+						total = adjusted << 10;
+
+						// Green component
+						rgb >>= 8;
+						adjusted = (rgb & 0xff) * v;
+						adjusted = MIN((uint)(adjusted >> 8), 31U);
+						total |= (adjusted << 5);
+
+						// Blue component
+						rgb >>= 8;
+						adjusted = (rgb & 0xff) * v;
+						adjusted = MIN((uint)(adjusted >> 8), 31U);
+						total |= adjusted;
+
+						// Write out pixel from inverse table
+						*destP = inverseColorTable[total];
+					}
+				} else {
+					// Normal pixel
+					*destP = v;
+				}
+			}
+
+			++destP;
+			if (depthP)
+				++depthP;
+		}
+	}
+}
+
+} // namespace M4