/***************************************************************************************** Speed Attack video hardware emulation *****************************************************************************************/ #include "emu.h" #include "includes/speedatk.h" #include "video/mc6845.h" PALETTE_INIT( speedatk ) { int i; /* allocate the colortable */ machine.colortable = colortable_alloc(machine, 0x10); /* create a lookup table for the palette */ for (i = 0; i < 0x10; i++) { int bit0, bit1, bit2; int r, g, b; /* red component */ bit0 = (color_prom[i] >> 0) & 0x01; bit1 = (color_prom[i] >> 1) & 0x01; bit2 = (color_prom[i] >> 2) & 0x01; r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; /* green component */ bit0 = (color_prom[i] >> 3) & 0x01; bit1 = (color_prom[i] >> 4) & 0x01; bit2 = (color_prom[i] >> 5) & 0x01; g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; /* blue component */ bit0 = 0; bit1 = (color_prom[i] >> 6) & 0x01; bit2 = (color_prom[i] >> 7) & 0x01; b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; colortable_palette_set_color(machine.colortable, i, MAKE_RGB(r, g, b)); } /* color_prom now points to the beginning of the lookup table */ color_prom += 0x20; for (i = 0; i < 0x100; i++) { UINT8 ctabentry = color_prom[i] & 0x0f; colortable_entry_set_value(machine.colortable, i, ctabentry); } } WRITE8_HANDLER( speedatk_videoram_w ) { speedatk_state *state = space->machine().driver_data(); state->m_videoram[offset] = data; } WRITE8_HANDLER( speedatk_colorram_w ) { speedatk_state *state = space->machine().driver_data(); state->m_colorram[offset] = data; } VIDEO_START( speedatk ) { } WRITE8_HANDLER( speedatk_6845_w ) { speedatk_state *state = space->machine().driver_data(); if(offset == 0) { state->m_crtc_index = data; space->machine().device("crtc")->address_w(*space,0,data); } else { state->m_crtc_vreg[state->m_crtc_index] = data; space->machine().device("crtc")->register_w(*space,0,data); } } SCREEN_UPDATE( speedatk ) { speedatk_state *state = screen->machine().driver_data(); int x,y; int count; UINT16 tile; UINT8 color, region; bitmap_fill(bitmap, cliprect, 0); count = (state->m_crtc_vreg[0x0c]<<8)|(state->m_crtc_vreg[0x0d] & 0xff); if(state->m_flip_scr) { count = 0x3ff - count; } for(y=0;ym_crtc_vreg[6];y++) { for(x=0;xm_crtc_vreg[1];x++) { tile = state->m_videoram[count] + ((state->m_colorram[count] & 0xe0) << 3); color = state->m_colorram[count] & 0x1f; region = (state->m_colorram[count] & 0x10) >> 4; drawgfx_opaque(bitmap,cliprect,screen->machine().gfx[region],tile,color,state->m_flip_scr,state->m_flip_scr,x*8,y*8); count = (state->m_flip_scr) ? count-1 : count+1; count&=0x3ff; } } return 0; }