dreamcast/vga.cpp
Zack Buhman 963aa75990 scene: rotating triangle
This now works on real dreamcast hardware.
2023-12-04 09:53:27 +08:00

160 lines
4.3 KiB
C++

#include <stdint.h>
#include "sh7091.h"
#include "sh7091_bits.h"
#include "holly.h"
#include "holly/core_bits.h"
#include "aica.h"
#include "memorymap.h"
#include "vga.h"
#include "rgb.h"
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__MASK;
}
void vga1()
{
holly.FB_R_CTRL = holly.FB_R_CTRL & ~fb_r_ctrl::fb_enable;
holly.VO_CONTROL |= vo_control::blank_video;
holly.FB_R_SIZE = 0;
holly.SPG_VBLANK_INT = spg_vblank_int::vblank_out_interrupt_line_number(0x0015)
| spg_vblank_int::vblank_in_interrupt_line_number(0x0208);
holly.SPG_CONTROL = spg_control::sync_direction::output;
constexpr uint32_t hbstart = 0x0345;
holly.SPG_HBLANK = spg_hblank::hbend(0x007e) // default
| spg_hblank::hbstart(hbstart); // default
holly.SPG_LOAD = spg_load::vcount(0x020c) // default
| spg_load::hcount(0x0359); // non-default
holly.SPG_VBLANK = spg_vblank::vbend(0x0028) // non-default
| spg_vblank::vbstart(0x0208); // non-default
holly.SPG_WIDTH = spg_width::eqwidth(0x000f)
| spg_width::bpwidth(0x0319)
| spg_width::vswidth(0x0003)
| spg_width::hswidth(0x003f);
constexpr uint32_t starty = 0x028;
holly.VO_STARTX = vo_startx::horizontal_start_position(0x0a8);
holly.VO_STARTY = vo_starty::vertical_start_position_on_field_2(starty)
| vo_starty::vertical_start_position_on_field_1(starty);
holly.SPG_HBLANK_INT = spg_hblank_int::line_comp_val(hbstart);
}
void vga2()
{
holly.FB_BURSTCTRL = fb_burstctrl::wr_burst(0x09)
| fb_burstctrl::vid_lat(0x3f)
| fb_burstctrl::vid_burst(0x39);
constexpr uint32_t x_size = 640;
constexpr uint32_t y_size = 480;
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 - 3)
| fb_r_size::fb_x_size((x_size * 16) / 32 - 1);
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_W_SOF1 = fb_w_sof1::frame_buffer_write_address_frame_1(0);
holly.FB_W_SOF2 = fb_w_sof2::frame_buffer_write_address_frame_2(0);
holly.FB_R_SOF1 = fb_r_sof1::frame_buffer_read_address_frame_1(0);
holly.FB_R_SOF2 = fb_r_sof2::frame_buffer_read_address_frame_2(0);
holly.FB_R_CTRL = fb_r_ctrl::vclk_div::pclk_vclk_1
| fb_r_ctrl::fb_depth::_0565_rgb_16bit
| fb_r_ctrl::fb_enable;
#define DVE_OUTPUT_MODE (&aica[0x2c00])
#define DVE_OUTPUT_MODE__VGA (0b00 << 0)
*DVE_OUTPUT_MODE = DVE_OUTPUT_MODE__VGA;
#undef DVE_OUTPUT_MODE
#undef DVE_OUTPUT_MODE__VGA
}
void v_sync_in()
{
#define V_SYNC (1<<13)
while (!(V_SYNC & holly.SPG_STATUS)) {
asm volatile ("nop");
}
while ((V_SYNC & holly.SPG_STATUS)) {
asm volatile ("nop");
}
#undef V_SYNC
}
void v_sync_out()
{
#define V_SYNC (1<<13)
while ((V_SYNC & holly.SPG_STATUS)) {
asm volatile ("nop");
}
while (!(V_SYNC & holly.SPG_STATUS)) {
asm volatile ("nop");
}
#undef V_SYNC
}
void vga()
{
get_cable_type();
holly.SOFTRESET = softreset::sdram_if_soft_reset
| softreset::pipeline_soft_reset
| softreset::ta_soft_reset;
holly.TEXT_CONTROL = text_control::stride(3);
vga1();
vga2();
holly.VO_BORDER_COL = vo_border_col::red(0x00)
| vo_border_col::green(0xff)
| vo_border_col::blue(0x00);
holly.VO_CONTROL = vo_control::pclk_delay(0x16);
holly.SDRAM_CFG = 0x15D1C951;
holly.SDRAM_REFRESH = 0x00000020;
v_sync_in();
holly.SOFTRESET = 0;
}
void fill_framebuffer()
{
volatile uint16_t * vram = reinterpret_cast<volatile uint16_t *>(texture_memory);
for (int y = 0; y < 480; y++) {
for (int x = 0; x < 640; x++) {
struct hsv hsv = {(y * 255) / 480, 255, 255};
struct rgb rgb = hsv_to_rgb(hsv);
vram[y * 640 + x] = ((rgb.r >> 3) << 11) | ((rgb.g >> 2) << 5) | ((rgb.b >> 3) << 0);
}
}
vram[0] = 0xf0ff;
vram[10] = 0xf0ff;
}