Avoid magic number and fix in trasparent reading from VRAM

2 files changed, 9 insertions, 5 deletions

diff --git a/tr8vm.c b/tr8vm.c
index fdede7c..f553614 100644
--- a/tr8vm.c
+++ b/tr8vm.c
@@ -96,13 +96,13 @@ uint32_t *fb_data = NULL;
 
 static void update_fb()
 {
-    for (uint16_t addr = 0; addr < 16384; addr++)
+    for (uint16_t addr = 0; addr < VIDEO_RAM_LEN; addr++)
         fb_data[addr] = palette[ram[VIDEO_RAM + addr] & 15];
 }
 
 void write_m(uint16_t addr, uint8_t b)
 {
-    if (addr >= VIDEO_RAM && addr < VIDEO_RAM + 16384)
+    if (addr >= VIDEO_RAM && addr < VIDEO_RAM + VIDEO_RAM_LEN)
         fb_data[addr - VIDEO_RAM] = palette[b & 15];
 
     ram[addr] = b;
@@ -159,7 +159,7 @@ static void update_ctl(SDL_Event *ev)
 
 uint8_t blt_set = 0;
 uint8_t blt_paramc = 0;
-uint8_t blt_param[6] = { 0 };
+int8_t blt_param[6] = { 0 };
 
 uint8_t port(uint8_t p, uint8_t v)
 {
@@ -191,7 +191,7 @@ uint8_t port(uint8_t p, uint8_t v)
                 if (v & 1)
                 {
                     uint16_t src = blt_param[0] | (blt_param[1] << 8);
-                    uint16_t dst = VIDEO_RAM + blt_param[2] + blt_param[3] * 128;
+                    uint16_t dst = VIDEO_RAM + blt_param[2] + blt_param[3] * TR8_W;
 
                     for (uint8_t y = 0; y < blt_param[5]; y++)
                         for (uint8_t x = 0; x < blt_param[4]; x++)
@@ -208,7 +208,7 @@ uint8_t port(uint8_t p, uint8_t v)
                 /* read from vram */
                 else
                 {
-                    uint16_t src = VIDEO_RAM + blt_param[2] + blt_param[3] * 128;
+                    uint16_t src = VIDEO_RAM + blt_param[2] + blt_param[3] * TR8_W;
                     uint16_t dst = blt_param[0] | (blt_param[1] << 8);
 
                     for (uint8_t y = 0; y < blt_param[5]; y++)
@@ -218,7 +218,10 @@ uint8_t port(uint8_t p, uint8_t v)
 
                             /* skip transparent if transparent flag is set */
                             if ((v & 2) && (b & 128))
+                            {
+                                dst++;
                                 continue;
+                            }
 
                             write_m(dst++, b);
                         }
diff --git a/vm.h b/vm.h
index 118ea25..9ba93ed 100644
--- a/vm.h
+++ b/vm.h
@@ -26,6 +26,7 @@
 #define _TR8_H
 
 #define VIDEO_RAM 0xbf00
+#define VIDEO_RAM_LEN 16384
 #define FRAME_INT_VECT 0xff00
 
 typedef struct