cleanup delphine_unpack()

unpack.cpp

@@ -6,48 +6,55 @@
 
 #include "unpack.h"
 
+struct UnpackCtx {
+	int size, datasize;
+	uint32_t crc;
+	uint32_t bits;
+	uint8_t *dst;
+	const uint8_t *src;
+};
 
-static int rcr(UnpackCtx *uc, int CF) {
-	int rCF = (uc->chk & 1);
-	uc->chk >>= 1;
+static int shiftBit(UnpackCtx *uc, int CF) {
+	int rCF = (uc->bits & 1);
+	uc->bits >>= 1;
 	if (CF) {
-		uc->chk |= 0x80000000;
+		uc->bits |= 0x80000000;
 	}
 	return rCF;
 }
 
-static int next_chunk(UnpackCtx *uc) {
-	int CF = rcr(uc, 0);
-	if (uc->chk == 0) {
-		uc->chk = READ_BE_UINT32(uc->src); uc->src -= 4;
-		uc->crc ^= uc->chk;
-		CF = rcr(uc, 1);
+static int nextBit(UnpackCtx *uc) {
+	int CF = shiftBit(uc, 0);
+	if (uc->bits == 0) {
+		uc->bits = READ_BE_UINT32(uc->src); uc->src -= 4;
+		uc->crc ^= uc->bits;
+		CF = shiftBit(uc, 1);
 	}
 	return CF;
 }
 
-static uint16_t get_code(UnpackCtx *uc, uint8_t num_chunks) {
+static uint16_t getBits(UnpackCtx *uc, uint8_t num_bits) {
 	uint16_t c = 0;
-	while (num_chunks--) {
+	while (num_bits--) {
 		c <<= 1;
-		if (next_chunk(uc)) {
+		if (nextBit(uc)) {
 			c |= 1;
 		}
 	}
 	return c;
 }
 
-static void dec_unk1(UnpackCtx *uc, uint8_t num_chunks, uint8_t add_count) {
-	uint16_t count = get_code(uc, num_chunks) + add_count + 1;
+static void unpackHelper1(UnpackCtx *uc, uint8_t num_bits, uint8_t add_count) {
+	uint16_t count = getBits(uc, num_bits) + add_count + 1;
 	uc->datasize -= count;
 	while (count--) {
-		*uc->dst = (uint8_t)get_code(uc, 8);
+		*uc->dst = (uint8_t)getBits(uc, 8);
 		--uc->dst;
 	}
 }
 
-static void dec_unk2(UnpackCtx *uc, uint8_t num_chunks) {
-	uint16_t i = get_code(uc, num_chunks);
+static void unpackHelper2(UnpackCtx *uc, uint8_t num_bits) {
+	uint16_t i = getBits(uc, num_bits);
 	uint16_t count = uc->size + 1;
 	uc->datasize -= count;
 	while (count--) {
@@ -63,26 +70,26 @@ bool delphine_unpack(uint8_t *dst, const uint8_t *src, int len) {
 	uc.dst = dst + uc.datasize - 1;
 	uc.size = 0;
 	uc.crc = READ_BE_UINT32(uc.src); uc.src -= 4;
-	uc.chk = READ_BE_UINT32(uc.src); uc.src -= 4;
-	uc.crc ^= uc.chk;
+	uc.bits = READ_BE_UINT32(uc.src); uc.src -= 4;
+	uc.crc ^= uc.bits;
 	do {
-		if (!next_chunk(&uc)) {
+		if (!nextBit(&uc)) {
 			uc.size = 1;
-			if (!next_chunk(&uc)) {
-				dec_unk1(&uc, 3, 0);
+			if (!nextBit(&uc)) {
+				unpackHelper1(&uc, 3, 0);
 			} else {
-				dec_unk2(&uc, 8);
+				unpackHelper2(&uc, 8);
 			}
 		} else {
-			uint16_t c = get_code(&uc, 2);
+			uint16_t c = getBits(&uc, 2);
 			if (c == 3) {
-				dec_unk1(&uc, 8, 8);
+				unpackHelper1(&uc, 8, 8);
 			} else if (c < 2) {
 				uc.size = c + 2;
-				dec_unk2(&uc, c + 9);
+				unpackHelper2(&uc, c + 9);
 			} else {
-				uc.size = get_code(&uc, 8);
-				dec_unk2(&uc, 12);
+				uc.size = getBits(&uc, 8);
+				unpackHelper2(&uc, 12);
 			}
 		}
 	} while (uc.datasize > 0);

unpack.h

@@ -9,16 +9,6 @@
 
 #include "intern.h"
 
-
-struct UnpackCtx {
-	int size, datasize;
-	uint32_t crc;
-	uint32_t chk;
-	uint8_t *dst;
-	const uint8_t *src;
-};
-
 extern bool delphine_unpack(uint8_t *dst, const uint8_t *src, int len);
 
-
 #endif // UNPACK_H__