cd: pull in Genesis-Plus-GX CD gfx code

[picodrive.git] / pico / cd / gfx_cd.c

diff --git a/pico/cd/gfx_cd.c b/pico/cd/gfx_cd.c
index 96d44f2..085c5e3 100644 (file)
--- a/pico/cd/gfx_cd.c
+++ b/pico/cd/gfx_cd.c
@@ -10,6 +10,8 @@
 #undef dprintf
 #define dprintf(...)
 
+#define UPDATE_CYCLES 20000
+
 #define _rot_comp Pico_mcd->rot_comp
 
 static void gfx_do_line(unsigned int func, unsigned short *stamp_base,
@@ -17,7 +19,8 @@ static void gfx_do_line(unsigned int func, unsigned short *stamp_base,
 
 static void gfx_cd_start(void)
 {
-       int w, h;
+       int w, h, cycles;
+       int y_step;
 
        w = _rot_comp.Reg_62;
        h = _rot_comp.Reg_64;
@@ -34,10 +37,6 @@ static void gfx_cd_start(void)
        _rot_comp.YD = (_rot_comp.Reg_60 >> 3) & 7;
        _rot_comp.Vector_Adr = (_rot_comp.Reg_66 & 0xfffe) << 2;
 
-       _rot_comp.Reg_58 |= 0x8000;     // Stamp_Size,  we start a new GFX operation
-
-       pcd_event_schedule_s68k(PCD_EVENT_GFX, 5 * w * h);
-
        switch (_rot_comp.Reg_58 & 6)   // Scr_16?
        {
                case 0: // ?
@@ -54,17 +53,57 @@ static void gfx_cd_start(void)
                        break;
        }
 
+       _rot_comp.Reg_58 |= 0x8000;     // Stamp_Size,  we start a new GFX operation
+
+       cycles = 5 * w * h;
+       if (cycles > UPDATE_CYCLES)
+               y_step = (UPDATE_CYCLES + 5 * w - 1) / (5 * w);
+       else
+               y_step = h;
+
+       _rot_comp.y_step = y_step;
+       pcd_event_schedule_s68k(PCD_EVENT_GFX, 5 * w * y_step);
+}
+
+void gfx_cd_update(unsigned int cycles)
+{
+       int w = _rot_comp.Reg_62;
+       int h, next;
+
+       if (!(Pico_mcd->rot_comp.Reg_58 & 0x8000))
+               return;
+
+       h = _rot_comp.Reg_64;
+       _rot_comp.Reg_64 -= _rot_comp.y_step;
+
+       if ((int)_rot_comp.Reg_64 <= 0) {
+               Pico_mcd->rot_comp.Reg_58 &= 0x7fff;
+               Pico_mcd->rot_comp.Reg_64  = 0;
+               if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN1) {
+                       elprintf(EL_INTS  |EL_CD, "s68k: gfx_cd irq 1");
+                       SekInterruptS68k(1);
+               }
+       }
+       else {
+               next = _rot_comp.Reg_64;
+               if (next > _rot_comp.y_step)
+                       next = _rot_comp.y_step;
+
+               pcd_event_schedule(cycles, PCD_EVENT_GFX, 5 * w * next);
+               h = _rot_comp.y_step;
+       }
+
        if (PicoOpt & POPT_EN_MCD_GFX)
        {
                unsigned int func = _rot_comp.Function;
-               unsigned short *stamp_base = (unsigned short *) (Pico_mcd->word_ram2M + _rot_comp.Stamp_Map_Adr);
+               unsigned short *stamp_base = (unsigned short *)
+                       (Pico_mcd->word_ram2M + _rot_comp.Stamp_Map_Adr);
 
                while (h--)
                        gfx_do_line(func, stamp_base, w);
        }
 }
 
-
 PICO_INTERNAL_ASM unsigned int gfx_cd_read(unsigned int a)
 {
        unsigned int d = 0;
@@ -76,12 +115,7 @@ PICO_INTERNAL_ASM unsigned int gfx_cd_read(unsigned int a)
                case 0x5E: d = _rot_comp.Reg_5E; break;
                case 0x60: d = _rot_comp.Reg_60; break;
                case 0x62: d = _rot_comp.Reg_62; break;
-               case 0x64:
-                       d = _rot_comp.Reg_64;
-                       if (_rot_comp.Reg_64 > 1)
-                               // fudge..
-                               _rot_comp.Reg_64--;
-                       break;
+               case 0x64: d = _rot_comp.Reg_64; break;
                case 0x66: break;
                default: dprintf("gfx_cd_read FIXME: unexpected address: %02x", a); break;
        }