move fcn_004552b7 to bit_functions.c and complete it

2 files changed, 72 insertions, 16 deletions

diff --git a/csrc/bit_functions.c b/csrc/bit_functions.c
new file mode 100644
index 0000000..b0be170
--- /dev/null
+++ b/csrc/bit_functions.c
@@ -0,0 +1,71 @@
+#include <stdint.h>
+#include <stddef.h>
+
+typedef void (*bit_f)(uint16_t*, uint16_t*, uint8_t*, size_t);
+extern uint32_t pixel_fmt;
+
+void fcn_455337(uint16_t *edi, uint16_t *esi, uint8_t *ebx, size_t ecx)
+{
+	do {
+		uint16_t ax = *esi;
+		esi++;
+
+		uint8_t dl = ebx[ax & 0x1f];
+		uint8_t dh = ebx[(ax >> 5) & 0x1f];
+		uint8_t al = ebx[(ax >> 10) & 0x1f];
+		ax = ((uint16_t)(al & 0x3f) << 10) | ((uint16_t)(dh & 0x1f) << 5) | (dl & 0x1f);
+
+		*edi = ax;
+		edi++;
+	} while (--ecx);
+}
+
+void fcn_45536c(uint16_t *edi, uint16_t *esi, uint8_t *ebx, size_t ecx)
+{
+	do {
+		uint32_t ax = *esi;
+		esi++;
+
+		uint8_t dl = ebx[ax & 0x1f];
+		uint8_t dh = ebx[(ax >> 6) & 0x1f];
+		uint16_t dx = ((uint16_t)dh << 8) | dl;
+		uint8_t al = ebx[(ax >> 11) & 0x1f];
+		ax = ((uint16_t)(al & 0x1f) << 11) | (((dx >> 7) & 0x3f) << 5) | (dx & 0x1f);
+
+		*edi = ax;
+		edi++;
+	} while (--ecx);
+}
+
+void fcn_4553a1(uint16_t *edi, uint16_t *esi, uint8_t *ebx, size_t ecx)
+{
+	ebx = (uint8_t*)(((long)ebx) >> 1);
+	do {
+		uint16_t ax = *esi;
+		esi++;
+
+		uint8_t dl = ebx[ax & 0xf];
+		uint8_t dh = ebx[(ax >> 4) & 0xf];
+		uint8_t al = ebx[(ax >> 8) & 0xf];
+		ax = ((uint16_t)(dh & 0xf) << 12) | ((uint16_t)al << 4) | (dl & 0xf);
+
+		*edi = ax;
+		edi++;
+	} while (--ecx);
+}
+
+const bit_f ftable_485958[] = {
+	fcn_455337, fcn_45536c, fcn_45536c, fcn_4553a1
+};
+const uint32_t ftable_485968[] = { 
+	0x00455442U, 0x00455480U, 0x00455480U, 0x004554beU
+};
+const uint32_t ftable_485978[] = { 
+	0x004555ebU, 0x00455628U, 0x0045566eU, 0x004556abU
+};
+
+void fcn_004552b7(void * dst, void * src, size_t a3, int a4)
+{
+	ftable_485958[pixel_fmt](dst, src, (uint8_t*)(0x485d68 + (a4 << 5)), a3 >> 1);
+}
+
diff --git a/csrc/game_init.c b/csrc/game_init.c
index d2cdcfe..ea2c16f 100644
--- a/csrc/game_init.c
+++ b/csrc/game_init.c
@@ -8,21 +8,6 @@ int winning_condition[6] = { 0, 100, 50, 10, 5, 3 }; // 0x46cc00
 int game_initial_fund; // 0x49908c
 int traffic_initial; // 0x46cb44
 
-const uint32_t ftable_485958[] = {
-  0x00455337U, 0x0045536cU, 0x0045536cU, 0x004553a1U, 0x00455442U,
-  0x00455480U, 0x00455480U, 0x004554beU, 0x004555ebU, 0x00455628U,
-  0x0045566eU, 0x004556abU
-}; /* TODO: analyze these functions */
-
-void fcn_004552b7(void * a1, void * a2, int a3, int a4)
-{
-	edi = a1;
-	esi = a2;
-	ecx = a3 >> 1;
-	ebx = 0x485d68 + (a4 << 5);
-	ftable_485958[dw_47637c](); /* function using esi, edi, ebx, ecx registers */
-}
-
 void fcn_00445a4d(int a1, int a2)
 {
 	int t = a1 * 15;
@@ -48,7 +33,7 @@ int init_new_game(int a0)
 	dw_48a358 = malloc(0x96000);
 	mkf_jump = load_mkf("JUMP.MKF");
 	read_mkf(mkf_jump, w_4991b6*4+w_4991b8 /* sign ext */, dw_48a358, NULL);
-	fcn_004552b7(dw_48a354, dw_48a358, 0x96000, -16);
+	fcn_004552b7(dw_48a354, dw_48a358, 0x96000, -16); /* @ bit_functions.c */
 	dw_48a3a4 = allocate_some_struct(440, 155, 0, 0);
 	dw_48a3a0 = allocate_some_struct(192, 461, 0, 0);
 	dw_48a3b8 = read_mkf(dw_48a3b0, 8, NULL, NULL);