TOOLS: Restore support for DXA compression type 12

scummvm · ccawley2011 · Apr 4, 2023 · Apr 4, 2023 · Apr 4, 2023 · Apr 4, 2023
commit fe8c8da8424ac178dc13b24b48b9558f8f650a70
diff --git a/encode_dxa.cpp b/encode_dxa.cpp
@@ -60,6 +60,7 @@ class DxaEncoder {
 	void m13blockDelta(byte *frame, int x, int y, int x2, int y2, DiffStruct &diff);
 	bool m13motionVector(byte *frame, int x, int y, int w, int h, int &mx, int &my);
 	int m13countColors(byte *block, byte *pixels, unsigned long &code, int &codeSize);
+	uLong m12encode(byte *frame, byte *outbuf);
 	uLong m13encode(byte *frame, byte *outbuf);
 
 public:
@@ -196,6 +197,57 @@ void DxaEncoder::writeFrame(byte *frame, byte *palette) {
 				delete[] outbuf2;
 				delete[] xorbuf;
 
+				break;
+			}
+                case 12:
+                        {
+				uLong outsize1 = _width * _workheight;
+				uLong outsize2 = outsize1;
+				uLong outsize3 = outsize1*2;
+				uLong outsize4 = outsize1;
+				uLong outsize;
+				uint8 *outbuf;
+				uint8 *outbuf1 = new uint8[outsize1];
+				uint8 *outbuf2 = new uint8[outsize2];
+				uint8 *outbuf3 = new uint8[outsize3];
+				uint8 *outbuf4 = new uint8[outsize4];
+				uint8 *xorbuf = new uint8[_width * _workheight];
+
+				for (int i = 0; i < _width * _workheight; i++)
+					xorbuf[i] = _prevframe[i] ^ frame[i];
+
+				compress2(outbuf1, &outsize1, xorbuf, _width * _workheight, 9);
+				compress2(outbuf2, &outsize2, frame, _width * _workheight, 9);
+				if (outsize1 < outsize2) {
+					compType = 3;
+					outsize = outsize1;
+					outbuf = outbuf1;
+				} else {
+					compType = 2;
+					outsize = outsize2;
+					outbuf = outbuf2;
+				}
+
+				outsize3 = m12encode(frame, outbuf3);
+
+				compress2(outbuf4, &outsize4, outbuf3, outsize3, 9);
+
+				if (outsize4 < outsize) {
+					compType = 12;
+					outsize = outsize4;
+					outbuf = outbuf4;
+				}
+
+				_dxa.writeByte(compType);
+				_dxa.writeUint32BE(outsize);
+				_dxa.write(outbuf, outsize);
+
+				delete[] outbuf1;
+				delete[] outbuf2;
+				delete[] outbuf3;
+				delete[] outbuf4;
+				delete[] xorbuf;
+
 				break;
 			}
 		case 13:
@@ -382,6 +434,86 @@ void DxaEncoder::grabBlock(byte *frame, int x, int y, int blockw, int blockh, by
 	}
 }
 
+uLong DxaEncoder::m12encode(byte *frame, byte *outbuf) {
+	byte *outb = outbuf;
+	byte color;
+	int mx, my;
+	DiffStruct diff;
+
+	for (int by = 0; by < _workheight; by += BLOCKH) {
+		for (int bx = 0; bx < _width; bx += BLOCKW) {
+			if (m13blocksAreEqual(frame, bx, by, bx, by, BLOCKW, BLOCKH)) {
+				*outb++ = 0;
+				continue;
+			}
+
+			if (m13blockIsSolidColor(frame, bx, by, BLOCKW, BLOCKH, color)) {
+				*outb++ = 2;
+				*outb++ = color;
+				continue;
+			}
+
+			if (m13motionVector(frame, bx, by, BLOCKW, BLOCKH, mx, my)) {
+				byte mbyte = 0;
+				if (mx < 0) mbyte |= 0x80;
+				mbyte |= (abs(mx) & 7) << 4;
+				if (my < 0) mbyte |= 0x08;
+				mbyte |= abs(my) & 7;
+				*outb++ = 4;
+				*outb++ = mbyte;
+				continue;
+			}
+
+			m13blockDelta(frame, bx, by, bx, by, diff);
+
+			if (diff.count >= 14) {
+				// in this case we store all 16 pixels
+				*outb++ = 3;
+				byte *b2 = (byte*)frame + bx + by * _width;
+				for (int yc = 0; yc < BLOCKH; yc++) {
+					memcpy(outb, b2, BLOCKW);
+					b2 += _width;
+					outb += BLOCKW;
+				}
+				continue;
+			} else {
+				static const struct { uint16 mask; uint8 sh1, sh2; } maskTbl[6] = {
+					{0xFF00, 0, 0},
+					{0x0FF0, 8, 0},
+					{0x00FF, 8, 8},
+					{0x0F0F, 8, 4},
+					{0xF0F0, 4, 0},
+					{0xF00F, 4, 4}
+				};
+
+				bool smallMask = false;
+
+				// here we check if the difference bitmap can be stored in only one byte
+				for (int m = 0; m < 6; m++) {
+					if ((diff.map & maskTbl[m].mask) == 0) {
+						smallMask = true;
+						*outb++ = 10 + m;
+						*outb++ = ((diff.map >> maskTbl[m].sh1) & 0xF0) | ((diff.map >> maskTbl[m].sh2) & 0x0F);
+						break;
+					}
+				}
+
+				if (!smallMask) {
+					*outb++ = 1;
+					WRITE_BE_UINT16(outb, diff.map);
+					outb += 2;
+				}
+
+				memcpy(outb, diff.pixels, diff.count);
+				outb += diff.count;
+				continue;
+			}
+		}
+	}
+
+	return outb - outbuf;
+}
+
 uLong DxaEncoder::m13encode(byte *frame, byte *outbuf) {
 
 	byte *codeB = _codeBuf;