// license:GPL-2.0+
// copyright-holders:Kevin Thacker,Sandro Ronco
/***************************************************************************
kc.c
Functions to emulate the video hardware of the kc85/4,kc85/3
***************************************************************************/
#include "emu.h"
#include "includes/kc.h"
#include "screen.h"
// 3 bit colour value. bit 2->green, bit 1->red, bit 0->blue
static const uint8_t kc85_palette[KC85_PALETTE_SIZE * 3] =
{
// foreground colours, "full" of each component
0x00, 0x00, 0x00, // black
0x00, 0x00, 0xd0, // blue
0xd0, 0x00, 0x00, // red
0xd0, 0x00, 0xd0, // magenta
0x00, 0xd0, 0x00, // green
0x00, 0xd0, 0xd0, // cyan
0xd0, 0xd0, 0x00, // yellow
0xd0, 0xd0, 0xd0, // white
// full of each component + half of another component
0x00, 0x00, 0x00, // black
0x60, 0x00, 0xa0, // violet
0xa0, 0x60, 0x00, // brown
0xa0, 0x00, 0x60, // red/purple
0x00, 0xa0, 0x60, // pastel green
0x00, 0x60, 0xa0, // sky blue
0xa0, 0xa0, 0x60, // yellow/green
0xd0, 0xd0, 0xd0, // white
// background colours are slightly darker than foreground colours
0x00, 0x00, 0x00, // black
0x00, 0x00, 0xa0, // dark blue
0xa0, 0x00, 0x00, // dark red
0xa0, 0x00, 0xa0, // dark magenta
0x00, 0xa0, 0x00, // dark green
0x00, 0xa0, 0xa0, // dark cyan
0xa0, 0xa0, 0x00, // dark yellow
0xa0, 0xa0, 0xa0 // dark white (grey)
};
/* Initialise the palette */
PALETTE_INIT_MEMBER(kc_state,kc85)
{
for (int i = 0; i < sizeof(kc85_palette) / 3; i++ )
palette.set_pen_color(i, kc85_palette[i*3], kc85_palette[i*3+1], kc85_palette[i*3+2]);
}
/* set new blink state */
WRITE_LINE_MEMBER( kc_state::video_toggle_blink_state )
{
if (state)
{
m_screen->update_partial(m_screen->vpos());
m_kc85_blink_state = !m_kc85_blink_state;
}
}
/* draw 8 pixels */
void kc_state::video_draw_8_pixels(bitmap_ind16 &bitmap, int x, int y, uint8_t colour_byte, uint8_t gfx_byte)
{
int pens[4];
int px;
if (m_high_resolution)
{
/* High resolution: 4 colors for block */
pens[0] = 0; // black
pens[1] = 2; // red
pens[2] = 5; // cyan
pens[3] = 7; // white
px = x;
for (int a=0; a<8; a++)
{
int pen = pens[((gfx_byte>>7) & 0x07) | ((colour_byte>>6) & 0x02)];
if ((px >= 0) && (px < bitmap.width()) && (y >= 0) && (y < bitmap.height()))
{
bitmap.pix16(y, px) = pen;
}
px++;
colour_byte <<= 1;
gfx_byte <<= 1;
}
}
else
{
/* Low resolution: 2 colors for block */
/* 16 foreground colours, 8 background colours */
/* bit 7 = 1: flash between foreground and background colour 0: no flash */
/* bit 6: adjusts foreground colours by adding half of another component */
/* bit 5,4,3 = foreground colour */
/* bit 5: background colour -> Green */
/* bit 4: background colour -> Red */
/* bit 3: background colour -> Blue */
/* bit 2,1,0 = background colour */
/* bit 2: background colour -> Green */
/* bit 1: background colour -> Red */
/* bit 0: background colour -> Blue */
int background_pen = (colour_byte&7) + 16;
int foreground_pen = ((colour_byte>>3) & 0x0f);
if ((colour_byte & 0x80) && m_kc85_blink_state && (m_pio_data[1] & 0x80))
{
foreground_pen = background_pen;
}
pens[0] = background_pen;
pens[1] = foreground_pen;
px = x;
for (int a=0; a<8; a++)
{
int pen = pens[(gfx_byte>>7) & 0x01];
if ((px >= 0) && (px < bitmap.width()) && (y >= 0) && (y < bitmap.height()))
{
bitmap.pix16(y, px) = pen;
}
px++;
gfx_byte = gfx_byte<<1;
}
}
}
/***************************************************************************
KC85/4 video hardware
***************************************************************************/
void kc85_4_state::video_start()
{
m_video_ram = machine().memory().region_alloc("videoram", (KC85_4_SCREEN_COLOUR_RAM_SIZE*2) + (KC85_4_SCREEN_PIXEL_RAM_SIZE*2), 1, ENDIANNESS_LITTLE)->base();
memset(m_video_ram, 0, (KC85_4_SCREEN_COLOUR_RAM_SIZE*2) + (KC85_4_SCREEN_PIXEL_RAM_SIZE*2));
m_display_video_ram = m_video_ram;
m_kc85_blink_state = 0;
}
void kc85_4_state::video_control_w(int data)
{
/* calculate address of video ram to display */
if (data & 1)
m_display_video_ram = m_video_ram + (KC85_4_SCREEN_PIXEL_RAM_SIZE + KC85_4_SCREEN_COLOUR_RAM_SIZE);
else
m_display_video_ram = m_video_ram;
m_high_resolution = (data & 0x08) ? 0 : 1;
}
uint32_t kc85_4_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
uint8_t *pixel_ram = m_display_video_ram;
uint8_t *colour_ram = pixel_ram + 0x04000;
for (int y=cliprect.min_y; y<=cliprect.max_y; y++)
{
for (int x=0; x<(KC85_SCREEN_WIDTH>>3); x++)
{
uint16_t offset = y | (x<<8);
uint8_t colour_byte = colour_ram[offset];
uint8_t gfx_byte = pixel_ram[offset];
video_draw_8_pixels(bitmap, (x<<3), y, colour_byte, gfx_byte);
}
}
return 0;
}
/***************************************************************************
KC85/3 video
***************************************************************************/
void kc_state::video_start()
{
m_video_ram = machine().memory().region_alloc("videoram", 0x4000, 1, ENDIANNESS_LITTLE)->base();
memset(m_video_ram, 0, 0x4000);
m_kc85_blink_state = 0;
}
uint32_t kc_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
/* colour ram takes up 0x02800 bytes */
uint8_t *pixel_ram = m_video_ram;
uint8_t *colour_ram = m_video_ram + 0x02800;
for (int y=cliprect.min_y; y<=cliprect.max_y; y++)
{
for (int x=0; x<(KC85_SCREEN_WIDTH>>3); x++)
{
int pixel_offset,colour_offset;
if ((x & 0x020)==0)
{
pixel_offset = (x & 0x01f) | (((y>>2) & 0x03)<<5) |
((y & 0x03)<<7) | (((y>>4) & 0x0f)<<9);
colour_offset = (x & 0x01f) | (((y>>2) & 0x03f)<<5);
}
else
{
/* 1 0 1 0 0 V7 V6 V1 V0 V3 V2 V5 V4 H2 H1 H0 */
/* 1 0 1 1 0 0 0 V7 V6 V3 V2 V5 V4 H2 H1 H0 */
pixel_offset = 0x02000+((x & 0x07) | (((y>>4) & 0x03)<<3) |
(((y>>2) & 0x03)<<5) | ((y & 0x03)<<7) | ((y>>6) & 0x03)<<9);
colour_offset = 0x0800+((x & 0x07) | (((y>>4) & 0x03)<<3) |
(((y>>2) & 0x03)<<5) | ((y>>6) & 0x03)<<7);
}
uint8_t colour_byte = colour_ram[colour_offset];
uint8_t gfx_byte = pixel_ram[pixel_offset];
video_draw_8_pixels(bitmap,(x<<3),y, colour_byte, gfx_byte);
}
}
return 0;
}