// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "video/resnet.h"
#include "includes/tp84.h"
/*
-The colortable is divided in 2 part:
-The characters colors
-The sprites colors
-The characters colors are indexed like this:
-2 bits from the characters
-4 bits from the attribute in tp84_bg_colorram
-2 bits from palette_bank (d3-d4)
-3 bits from palette_bank (d0-d1-d2)
-So, there is 2048 bytes for the characters
-The sprites colors are indexed like this:
-4 bits from the sprites (16 colors)
-4 bits from the attribute of the sprites
-3 bits from palette_bank (d0-d1-d2)
-So, there is 2048 bytes for the sprites
*/
/*
The RGB signals are generated by 3 proms 256X4 (prom 2C, 2D and 1E)
The resistors values are:
1K ohm
470 ohm
220 ohm
100 ohm
*/
void tp84_state::tp84_palette(palette_device &palette) const
{
const uint8_t *color_prom = memregion("proms")->base();
static constexpr int resistances[4] = { 1000, 470, 220, 100 };
// compute the color output resistor weights
double weights[4];
compute_resistor_weights(0, 255, -1.0,
4, resistances, weights, 470, 0,
0, nullptr, nullptr, 0, 0,
0, nullptr, nullptr, 0, 0);
// create a lookup table for the palette
for (int i = 0; i < 0x100; i++)
{
int bit0, bit1, bit2, bit3;
// red component
bit0 = BIT(color_prom[i | 0x000], 0);
bit1 = BIT(color_prom[i | 0x000], 1);
bit2 = BIT(color_prom[i | 0x000], 2);
bit3 = BIT(color_prom[i | 0x000], 3);
int const r = combine_weights(weights, bit0, bit1, bit2, bit3);
// green component
bit0 = BIT(color_prom[i | 0x100], 0);
bit1 = BIT(color_prom[i | 0x100], 1);
bit2 = BIT(color_prom[i | 0x100], 2);
bit3 = BIT(color_prom[i | 0x100], 3);
int const g = combine_weights(weights, bit0, bit1, bit2, bit3);
// blue component
bit0 = BIT(color_prom[i | 0x200], 0);
bit1 = BIT(color_prom[i | 0x200], 1);
bit2 = BIT(color_prom[i | 0x200], 2);
bit3 = BIT(color_prom[i | 0x200], 3);
int const b = combine_weights(weights, bit0, bit1, bit2, bit3);
palette.set_indirect_color(i, rgb_t(r, g, b));
}
// color_prom now points to the beginning of the lookup table
color_prom += 0x300;
// characters use colors 0x80-0xff, sprites use colors 0-0x7f
for (int i = 0; i < 0x200; i++)
{
for (int j = 0; j < 8; j++)
{
uint8_t const ctabentry = ((~i & 0x100) >> 1) | (j << 4) | (color_prom[i] & 0x0f);
palette.set_pen_indirect(((i & 0x100) << 3) | (j << 8) | (i & 0xff), ctabentry);
}
}
}
WRITE8_MEMBER(tp84_state::tp84_spriteram_w)
{
/* the game multiplexes the sprites, so update now */
// m_screen->update_now();
m_screen->update_partial(m_screen->vpos());
m_spriteram[offset] = data;
}
READ8_MEMBER(tp84_state::tp84_scanline_r)
{
/* reads 1V - 128V */
return m_screen->vpos();
}
TILE_GET_INFO_MEMBER(tp84_state::get_bg_tile_info)
{
int code = ((m_bg_colorram[tile_index] & 0x30) << 4) | m_bg_videoram[tile_index];
int color = ((*m_palette_bank & 0x07) << 6) |
((*m_palette_bank & 0x18) << 1) |
(m_bg_colorram[tile_index] & 0x0f);
int flags = TILE_FLIPYX(m_bg_colorram[tile_index] >> 6);
SET_TILE_INFO_MEMBER(0, code, color, flags);
}
TILE_GET_INFO_MEMBER(tp84_state::get_fg_tile_info)
{
int code = ((m_fg_colorram[tile_index] & 0x30) << 4) | m_fg_videoram[tile_index];
int color = ((*m_palette_bank & 0x07) << 6) |
((*m_palette_bank & 0x18) << 1) |
(m_fg_colorram[tile_index] & 0x0f);
int flags = TILE_FLIPYX(m_fg_colorram[tile_index] >> 6);
SET_TILE_INFO_MEMBER(0, code, color, flags);
}
void tp84_state::video_start()
{
m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(tp84_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
m_fg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(tp84_state::get_fg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32);
}
void tp84_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
{
int offs;
int palette_base = ((*m_palette_bank & 0x07) << 4);
for (offs = 0x5c; offs >= 0; offs -= 4)
{
int x = m_spriteram[offs];
int y = 240 - m_spriteram[offs + 3];
int code = m_spriteram[offs + 1];
int color = palette_base | (m_spriteram[offs + 2] & 0x0f);
int flip_x = ~m_spriteram[offs + 2] & 0x40;
int flip_y = m_spriteram[offs + 2] & 0x80;
m_gfxdecode->gfx(1)->transmask(bitmap,cliprect, code, color, flip_x, flip_y, x, y,
m_palette->transpen_mask(*m_gfxdecode->gfx(1), color, palette_base));
}
}
uint32_t tp84_state::screen_update_tp84(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
rectangle clip = cliprect;
const rectangle &visarea = screen.visible_area();
if (cliprect.min_y == screen.visible_area().min_y)
{
machine().tilemap().mark_all_dirty();
m_bg_tilemap->set_scrollx(0, *m_scroll_x);
m_bg_tilemap->set_scrolly(0, *m_scroll_y);
machine().tilemap().set_flip_all((m_flipscreen_x ? TILEMAP_FLIPX : 0) |
(m_flipscreen_y ? TILEMAP_FLIPY : 0));
}
m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0);
draw_sprites(bitmap, cliprect);
/* draw top status region */
clip.min_x = visarea.min_x;
clip.max_x = visarea.min_x + 15;
m_fg_tilemap->draw(screen, bitmap, clip, 0, 0);
/* draw bottom status region */
clip.min_x = visarea.max_x - 15;
clip.max_x = visarea.max_x;
m_fg_tilemap->draw(screen, bitmap, clip, 0, 0);
return 0;
}