dreamcast/holly/video_output.cpp
Zack Buhman 9e58a376bd video_output: correct fb_y_size
The y_size - 3 value was cargo-culted from Darkness.

The correct value appears to be y_size - 1, which also matches what is
documented in DCDBSysArc990907E
2025-05-22 04:39:30 -05:00

112 lines
2.8 KiB
C++

#include <cstdint>
#include "sh7091/sh7091.hpp"
#include "sh7091/serial.hpp"
#include "aica/aica.hpp"
#include "dve.hpp"
#include "holly.hpp"
#include "holly/core_bits.hpp"
#include "video_output.hpp"
#include "video_output_mode.inc"
namespace video_output {
void set_framebuffer_resolution(const uint32_t x_size, const uint32_t y_size)
{
holly.Y_COEFF = y_coeff::coefficient_1(0x80)
| y_coeff::coefficient_0_2(0x40);
// in 6.10 fixed point; 0x0400 is 1x vertical scale
holly.SCALER_CTL = scaler_ctl::vertical_scale_factor(0x0400);
holly.FB_BURSTCTRL = fb_burstctrl::wr_burst(0x09)
| fb_burstctrl::vid_lat(0x3f)
| fb_burstctrl::vid_burst(0x39);
holly.FB_X_CLIP = fb_x_clip::fb_x_clip_max(x_size - 1)
| fb_x_clip::fb_x_clip_min(0);
holly.FB_Y_CLIP = fb_y_clip::fb_y_clip_max(y_size - 1)
| fb_y_clip::fb_y_clip_min(0);
holly.FB_R_SIZE = fb_r_size::fb_modulus(1)
| fb_r_size::fb_y_size(y_size - 1)
| fb_r_size::fb_x_size((x_size * 16) / 32 - 1);
}
void set_mode(const struct mode& mode)
{
holly.FB_R_CTRL = mode.fb_r_ctrl
| fb_r_ctrl::fb_depth::_565_rgb_16bit
| fb_r_ctrl::fb_enable;
holly.SPG_LOAD = mode.spg_load;
holly.SPG_HBLANK = mode.spg_hblank;
holly.SPG_VBLANK = mode.spg_vblank;
holly.SPG_WIDTH = mode.spg_width;
holly.SPG_CONTROL = mode.spg_control;
holly.VO_STARTX = mode.vo_startx;
holly.VO_STARTY = mode.vo_starty;
holly.VO_CONTROL = mode.vo_control;
holly.SPG_HBLANK_INT = mode.spg_hblank_int;
holly.SPG_VBLANK_INT = mode.spg_vblank_int;
}
uint32_t get_cable_type()
{
// set all pins to input
sh7091.BSC.PCTRA = 0;
// get cable type from pins 9 + 8
return sh7091.BSC.PDTRA & pdtra::cable_type::bit_mask;
}
framebuffer_resolution set_mode_by_cable_type(uint32_t cable_type)
{
switch (cable_type) {
default: [[fallthrough]];
case pdtra::cable_type::vga:
set_mode(vga);
set_framebuffer_resolution(640, 480);
aica_sound.common.VREG(vreg::output_mode::vga);
return {640, 480};
break;
case pdtra::cable_type::rgb:
set_mode(ntsc_ni);
set_framebuffer_resolution(320, 240);
aica_sound.common.VREG(vreg::output_mode::rgb);
return {320, 240};
break;
case pdtra::cable_type::cvbs_yc:
set_mode(ntsc_ni);
set_framebuffer_resolution(320, 240);
aica_sound.common.VREG(vreg::output_mode::cvbs_yc);
return {320, 240};
break;
}
}
void set_mode_vga()
{
set_mode(vga);
set_framebuffer_resolution(640, 480);
aica_sound.common.VREG(vreg::output_mode::vga);
}
void reset_sdram()
{
holly.SOFTRESET = softreset::sdram_if_soft_reset
| softreset::pipeline_soft_reset
| softreset::ta_soft_reset;
holly.SDRAM_CFG = 0x15D1C951;
holly.SDRAM_REFRESH = 0x00000020;
holly.SOFTRESET = 0;
}
}