From c07f9fed9911ed6ac2586cedef9fd8f4a8fb6cb9 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Sun, 21 Oct 2018 18:42:49 -0400 Subject: [PATCH] Corrects test and implementation to pass the exhaustive VDP interrupt prediction test. --- Components/9918/9918.cpp | 24 ++++++++++--------- .../Clock SignalTests/MasterSystemVDPTests.mm | 4 ++-- 2 files changed, 15 insertions(+), 13 deletions(-) diff --git a/Components/9918/9918.cpp b/Components/9918/9918.cpp index 8fefcf24c..49cbc86c1 100644 --- a/Components/9918/9918.cpp +++ b/Components/9918/9918.cpp @@ -638,23 +638,31 @@ HalfCycles TMS9918::get_time_until_interrupt() { // Calculate the amount of time until the next end-of-frame interrupt. const int frame_length = 342 * mode_timing_.total_lines; - const int time_until_frame_interrupt = + int time_until_frame_interrupt = ( ((mode_timing_.end_of_frame_interrupt_position.row * 342) + mode_timing_.end_of_frame_interrupt_position.column + frame_length) - ((write_pointer_.row * 342) + write_pointer_.column) ) % frame_length; + if(!time_until_frame_interrupt) time_until_frame_interrupt = frame_length; if(!enable_line_interrupts_) return half_cycles_before_internal_cycles(time_until_frame_interrupt); - // Calculate the row upon which the next line interrupt will occur. + // Calculate when the next line interrupt will occur. int next_line_interrupt_row = -1; + int cycles_to_next_interrupt_threshold = mode_timing_.line_interrupt_position - write_pointer_.column; + int line_of_next_interrupt_threshold = write_pointer_.row; + if(cycles_to_next_interrupt_threshold <= 0) { + cycles_to_next_interrupt_threshold += 342; + ++line_of_next_interrupt_threshold; + } + if(is_sega_vdp(personality_)) { // If there is still time for a line interrupt this frame, that'll be it; // otherwise it'll be on the next frame, supposing there's ever time for // it at all. - if(write_pointer_.row+line_interrupt_counter <= mode_timing_.pixel_lines) { - next_line_interrupt_row = write_pointer_.row+line_interrupt_counter; + if(line_of_next_interrupt_threshold + line_interrupt_counter <= mode_timing_.pixel_lines) { + next_line_interrupt_row = line_of_next_interrupt_threshold + line_interrupt_counter; } else { if(line_interrupt_target <= mode_timing_.pixel_lines) next_line_interrupt_row = mode_timing_.total_lines + line_interrupt_target; @@ -671,10 +679,7 @@ HalfCycles TMS9918::get_time_until_interrupt() { // Figure out the number of internal cycles until the next line interrupt, which is the amount // of time to the next tick over and then next_line_interrupt_row - row_ lines further. - int local_cycles_until_next_tick = (mode_timing_.line_interrupt_position - write_pointer_.column + 342) % 342; - if(!local_cycles_until_next_tick) local_cycles_until_next_tick += 342; - const int local_cycles_until_line_interrupt = local_cycles_until_next_tick + (next_line_interrupt_row - write_pointer_.row) * 342; - + const int local_cycles_until_line_interrupt = cycles_to_next_interrupt_threshold + (next_line_interrupt_row - line_of_next_interrupt_threshold) * 342; if(!generate_interrupts_) return half_cycles_before_internal_cycles(local_cycles_until_line_interrupt); // Return whichever interrupt is closer. @@ -687,9 +692,6 @@ bool TMS9918::get_interrupt_line() { // MARK: - -// if(sprite.shift_position > 0 && !sprites_magnified_) -// sprite.shift_position *= 2; - void Base::draw_tms_character(int start, int end) { LineBuffer &line_buffer = line_buffers_[read_pointer_.row]; diff --git a/OSBindings/Mac/Clock SignalTests/MasterSystemVDPTests.mm b/OSBindings/Mac/Clock SignalTests/MasterSystemVDPTests.mm index c8c291049..de25c951a 100644 --- a/OSBindings/Mac/Clock SignalTests/MasterSystemVDPTests.mm +++ b/OSBindings/Mac/Clock SignalTests/MasterSystemVDPTests.mm @@ -120,7 +120,7 @@ TI::TMS::TMS9918 vdp(TI::TMS::Personality::SMSVDP); for(int c = 0; c < 256; ++c) { - for(int with_eof = 0; with_eof < 2; ++with_eof) { + for(int with_eof = (c < 192) ? 0 : 1; with_eof < 2; ++with_eof) { // Enable or disable end-of-frame interrupts as required. vdp.set_register(1, with_eof ? 0x20 : 0x00); vdp.set_register(1, 0x81); @@ -138,7 +138,7 @@ int last_time_until_interrupt = vdp.get_time_until_interrupt().as_int(); while(half_cycles--) { // Validate that an interrupt happened if one was expected, and clear anything that's present. - NSAssert(vdp.get_interrupt_line() == (last_time_until_interrupt == 0), @"Unexpected interrupt state change; position %d %d @ %d", c, with_eof, half_cycles); + NSAssert(vdp.get_interrupt_line() == (last_time_until_interrupt == 0), @"Unexpected interrupt state change; expected %d but got %d; position %d %d @ %d", (last_time_until_interrupt == 0), vdp.get_interrupt_line(), c, with_eof, half_cycles); vdp.get_register(1); vdp.run_for(HalfCycles(1));