diff options
Diffstat (limited to 'jag_video.c')
| -rw-r--r-- | jag_video.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/jag_video.c b/jag_video.c index 558281b..0a8f396 100644 --- a/jag_video.c +++ b/jag_video.c @@ -187,6 +187,27 @@ enum { OBJ_STOP }; +uint32_t jag_cycles_to_halfline(jag_video *context, uint32_t target) +{ + uint32_t cycles = context->regs[VID_HPERIOD] - (context->regs[VID_HCOUNT & 0x3FF]); + uint32_t num_lines; + if (context->regs[VID_VCOUNT] < target) { + num_lines = target - 1 - context->regs[VID_VCOUNT]; + } else { + num_lines = target + context->regs[VID_VPERIOD] - context->regs[VID_VCOUNT]; + } + cycles += num_lines * context->regs[VID_HPERIOD]; + return cycles; +} + +uint32_t jag_next_vid_interrupt(jag_video *context) +{ + if (context->regs[VID_VINT] > context->regs[VID_VPERIOD]) { + return 0xFFFFFFF; + } + return context->cycles + jag_cycles_to_halfline(context, context->regs[VID_VINT]); +} + void op_run(jag_video *context) { while (context->op.cycles < context->cycles) @@ -547,6 +568,9 @@ void jag_video_run(jag_video *context, uint32_t target_cycle) context->regs[VID_VCOUNT] = 0; } else { context->regs[VID_VCOUNT]++; + if (context->regs[VID_VCOUNT] == context->regs[VID_VINT]) { + context->cpu_int_pending |= BIT_CPU_VID_INT_ENABLED; + } } } else { context->regs[VID_HCOUNT]++; |