add sprites.h, rename files

lib/screen1.h

@@ -51,6 +51,9 @@ void screen1_prepare() {
    // fill name table with spaces (32)
    screen1_cls();
 
+   // clear all the sprites
+   tms_clear_sprites();
+
    // fill pattern table with 0
    tms_set_vram_write_addr(TMS_PATTERN_TABLE);
    for(word i=256*8;i!=0;i--) {

lib/screen2.h

@@ -4,20 +4,8 @@ const word SCREEN2_SIZE = (32*24);
 
 // prepare the screen 2 to be used as a bitmap
 void screen2_init_bitmap(byte color) {
-   // erase the first sprite pattern
-   tms_set_vram_write_addr(TMS_SPRITE_PATTERNS);    // start writing in the sprite patterns
-   for(byte i=0;i<8;i++) {
-      TMS_WRITE_DATA_PORT(0);      NOP; 
-   }
-
-   // set all sprite coordinates to 0
-   tms_set_vram_write_addr(TMS_SPRITE_ATTRS);       // start writing in the sprite attribute
-   for(byte i=0;i<32;i++) {
-      TMS_WRITE_DATA_PORT(0);      NOP;  // y coordinate
-      TMS_WRITE_DATA_PORT(0);      NOP;  // x coordinate
-      TMS_WRITE_DATA_PORT(0);      NOP;  // name
-      TMS_WRITE_DATA_PORT(i);      NOP;  // color
-   }
+   // erases all the sprites
+   tms_clear_sprites();
 
    // fill pattern table with 0 (clear screen)
    tms_set_vram_write_addr(TMS_PATTERN_TABLE);

lib/sprites.h

@@ -0,0 +1,17 @@
+// clears all the sprites
+void tms_clear_sprites() {
+   // fills first sprite pattern with 0
+   tms_set_vram_write_addr(TMS_SPRITE_PATTERNS);  
+   for(byte i=0;i<8;i++) {
+      TMS_WRITE_DATA_PORT(0);
+   }
+
+   // set sprite coordinates to (0,0) and set pattern name 0
+   tms_set_vram_write_addr(TMS_SPRITE_ATTRS);       
+   for(byte i=0;i<32;i++) {
+      TMS_WRITE_DATA_PORT((6+i)*8); NOP; NOP; NOP; NOP; // y coordinate
+      TMS_WRITE_DATA_PORT((6+i)*8); NOP; NOP; NOP; NOP; // x coordinate
+      TMS_WRITE_DATA_PORT(0);       NOP; NOP; NOP; NOP; // name
+      TMS_WRITE_DATA_PORT(i);       NOP; NOP; NOP; NOP; // color
+   }
+}

lib/tms9918.h

@@ -159,6 +159,7 @@ void tms_set_external_video(byte val) {
 
 #include "apple1.h"
 #include "font8x8.h"
+#include "sprites.h"
 #include "tms_screen1.h"
 #include "tms_screen2.h"
 #include "interrupt.h"