//--------------------------------------------------------------------------- // NEOPOP : Emulator as in Dreamland // // Copyright (c) 2001-2002 by neopop_uk //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 2 of the License, or // (at your option) any later version. See also the license.txt file for // additional informations. //--------------------------------------------------------------------------- /* //--------------------------------------------------------------------------- //========================================================================= gfx_scanline_mono.c //========================================================================= //--------------------------------------------------------------------------- History of changes: =================== 20 JUL 2002 - neopop_uk ======================================= - Cleaned and tidied up for the source release 22 JUL 2002 - neopop_uk ======================================= - Removed delayed settings retrieval, this is now done by 'interrupt.c' - Removed hack for scanline 0! - Fixed palettes - Inverted all colours (1's complement) to make correct LCD emulation 24 JUL 2002 - neopop_uk ======================================= - Added Negative/Positive colour switching 25 JUL 2002 - neopop_uk ======================================= - Fixed a stupid bug in the dimensions of the right side of the hardware window. 06 AUG 2002 - neopop_uk ======================================= - Switched to 16-bit [0BGR] rendering, should be much faster. 15 AUG 2002 - neopop_uk ======================================= - Changed parameter 4 of drawPattern from bool to _u16, for performance and compatiblity reasons. - Changed parameter 3 of Plot (pal_hi) from bool to _u16, and in turn parameter 6 of drawPattern - again for performance and compatiblity. 16 AUG 2002 - neopop_uk ======================================= - Optimised things a little by removing some extraneous pointer work //--------------------------------------------------------------------------- */ //inline int min(int a, int b){ return (a= (winw + winx) || x >= SCREEN_WIDTH) return; //Depth check, <= to stop later sprites overwriting pixels! if (depth <= zbuffer[x]) return; zbuffer[x] = depth; //Get the colour of the pixel if (pal_hi) data8 = palette_ptr[4 + index]; else data8 = palette_ptr[0 + index]; r = (data8 & 7) << 1; g = (data8 & 7) << 5; b = (data8 & 7) << 9; if (negative) cfb_scanline[x] = (r | g | b); else cfb_scanline[x] = ~(r | g | b); } static void drawPattern(_u8 screenx, _u16 tile, _u8 tiley, _u16 mirror, _u8* palette_ptr, _u16 pal, _u8 depth) { //Get the data for th e "tiley'th" line of "tile". _u16 data = *(_u16*)(ram + 0xA000 + (tile * 16) + (tiley * 2)); //Horizontal Flip if (mirror) { Plot(screenx + 7, palette_ptr, pal, (data & 0xC000) >> 0xE, depth); Plot(screenx + 6, palette_ptr, pal, (data & 0x3000) >> 0xC, depth); Plot(screenx + 5, palette_ptr, pal, (data & 0x0C00) >> 0xA, depth); Plot(screenx + 4, palette_ptr, pal, (data & 0x0300) >> 0x8, depth); Plot(screenx + 3, palette_ptr, pal, (data & 0x00C0) >> 0x6, depth); Plot(screenx + 2, palette_ptr, pal, (data & 0x0030) >> 0x4, depth); Plot(screenx + 1, palette_ptr, pal, (data & 0x000C) >> 0x2, depth); Plot(screenx + 0, palette_ptr, pal, (data & 0x0003) >> 0x0, depth); } else //Normal { Plot(screenx + 0, palette_ptr, pal, (data & 0xC000) >> 0xE, depth); Plot(screenx + 1, palette_ptr, pal, (data & 0x3000) >> 0xC, depth); Plot(screenx + 2, palette_ptr, pal, (data & 0x0C00) >> 0xA, depth); Plot(screenx + 3, palette_ptr, pal, (data & 0x0300) >> 0x8, depth); Plot(screenx + 4, palette_ptr, pal, (data & 0x00C0) >> 0x6, depth); Plot(screenx + 5, palette_ptr, pal, (data & 0x0030) >> 0x4, depth); Plot(screenx + 6, palette_ptr, pal, (data & 0x000C) >> 0x2, depth); Plot(screenx + 7, palette_ptr, pal, (data & 0x0003) >> 0x0, depth); } } static void gfx_draw_scroll1(_u8 depth) { _u8 tx, row, line; _u16 data16; line = scanline + scroll1y; row = line & 7; //Which row? //Draw Foreground scroll plane (Scroll 1) for (tx = 0; tx < 32; tx++) { data16 = *(_u16*)(ram + 0x9000 + ((tx + ((line >> 3) << 5)) << 1)); //Draw the line of the tile drawPattern((tx << 3) - scroll1x, data16 & 0x01FF, (data16 & 0x4000) ? 7 - row : row, data16 & 0x8000, ram + 0x8108, data16 & 0x2000, depth); } } static void gfx_draw_scroll2(_u8 depth) { _u8 tx, row, line; _u16 data16; line = scanline + scroll2y; row = line & 7; //Which row? //Draw Background scroll plane (Scroll 2) for (tx = 0; tx < 32; tx++) { data16 = *(_u16*)(ram + 0x9800 + ((tx + ((line >> 3) << 5)) << 1)); //Draw the line of the tile drawPattern((tx << 3) - scroll2x, data16 & 0x01FF, (data16 & 0x4000) ? 7 - row : row, data16 & 0x8000, ram + 0x8110, data16 & 0x2000, depth); } } void gfx_draw_scanline_mono(void) { _s16 lastSpriteX; _s16 lastSpriteY; int spr, x; _u16 data16; //Get the current scanline scanline = ram[0x8009]; cfb_scanline = cfb + (scanline * SCREEN_WIDTH); //Calculate fast offset memset(cfb_scanline, 0, SCREEN_WIDTH * sizeof(_u16)); memset(zbuffer, 0, SCREEN_WIDTH); //Window colour r = (_u16)oowc << 1; g = (_u16)oowc << 5; b = (_u16)oowc << 9; if (negative) data16 = (r | g | b); else data16 = ~(r | g | b); //Top if (scanline < winy) { for (x = 0; x < SCREEN_WIDTH; x++) cfb_scanline[x] = data16; } else { //Middle if (scanline < winy + winh) { for (x = 0; x < min(winx, SCREEN_WIDTH); x++) cfb_scanline[x] = data16; for (x = min(winx + winw, SCREEN_WIDTH); x < SCREEN_WIDTH; x++) cfb_scanline[x] = data16; } else //Bottom { for (x = 0; x < SCREEN_WIDTH; x++) cfb_scanline[x] = data16; } } //Ignore above and below the window's top and bottom if (scanline >= winy && scanline < winy + winh) { //Background colour Enabled? if ((bgc & 0xC0) == 0x80) { r = (_u16)(bgc & 7) << 1; g = (_u16)(bgc & 7) << 5; b = (_u16)(bgc & 7) << 9; data16 = ~(r | g | b); } else data16 = 0x0FFF; if (negative) data16 = ~data16; //Draw background! for (x = winx; x < min(winx + winw, SCREEN_WIDTH); x++) cfb_scanline[x] = data16; //Swap Front/Back scroll planes? if (planeSwap) { gfx_draw_scroll1(ZDEPTH_BACKGROUND_SCROLL); //Swap gfx_draw_scroll2(ZDEPTH_FOREGROUND_SCROLL); } else { gfx_draw_scroll2(ZDEPTH_BACKGROUND_SCROLL); //Normal gfx_draw_scroll1(ZDEPTH_FOREGROUND_SCROLL); } //Draw Sprites //Last sprite position, (defaults to top-left, sure?) lastSpriteX = 0; lastSpriteY = 0; for (spr = 0; spr < 64; spr++) { _u8 priority, row; _u8 sx = ram[0x8800 + (spr * 4) + 2]; //X position _u8 sy = ram[0x8800 + (spr * 4) + 3]; //Y position _s16 x = sx; _s16 y = sy; data16 = *(_u16*)(ram + 0x8800 + (spr * 4)); priority = (data16 & 0x1800) >> 11; if (data16 & 0x0400) x = lastSpriteX + sx; //Horizontal chain? if (data16 & 0x0200) y = lastSpriteY + sy; //Vertical chain? //Store the position for chaining lastSpriteX = x; lastSpriteY = y; //Visible? if (priority == 0) continue; //Scroll the sprite x += scrollsprx; y += scrollspry; //Off-screen? if (x > 248 && x < 256) x = x - 256; else x &= 0xFF; if (y > 248 && y < 256) y = y - 256; else y &= 0xFF; //In range? if (scanline >= y && scanline <= y + 7) { row = (scanline - y) & 7; //Which row? drawPattern((_u8)x, data16 & 0x01FF, (data16 & 0x4000) ? 7 - row : row, data16 & 0x8000, ram + 0x8100, data16 & 0x2000, priority << 1); } } } //========== } //=============================================================================