/* * crtc-draw.c - A line-based CRTC emulation (under construction). * * Written by * Ettore Perazzoli * Andre Fachat * * This file is part of VICE, the Versatile Commodore Emulator. * See README for copyright notice. * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307 USA. * */ #include "vice.h" #include #include #include "crtc-draw.h" #include "crtc.h" #include "crtctypes.h" #include "raster-modes.h" #include "types.h" /* * Bit expansion table: expands 4 bits to 4 bytes, * placing each bit in the lsb of the bytes. * The msb of the input is mapped to the lowest-address byte. * * The table maps nybbles at a time, since mapping a whole byte * would take 2 tables, each 16 times as big, and that would * not be so nice on the cpu cache. */ uint32_t dwg_table[16]; static void init_drawing_tables(void) { int byte, p; uint8_t msk; for (byte = 0; byte < 0x10; byte++) { for (msk = 0x08, p = 0; p < 4; msk >>= 1, p++) { *((uint8_t *)(dwg_table + byte) + p) = (byte & msk ? 1 : 0); } } } /***************************************************************************/ static void draw_standard_background(unsigned int start_pixel, unsigned int end_pixel) { memset(crtc.raster.draw_buffer_ptr + start_pixel, 0, end_pixel - start_pixel + 1); } /***************************************************************************/ /* inline function... */ static inline void DRAW(int reverse_flag, int offset, int scr_rel, int xs, int xc, int xe) { /* FIXME: `p' has to be aligned on a 4 byte boundary! Is there a better way than masking `offset'? */ uint8_t *p = crtc.raster.draw_buffer_ptr + (offset & ~3); uint32_t *pw = (uint32_t *)p; uint8_t *chargen_ptr, *screen_ptr; int screen_rel; int i, d; /* pointer to current chargen line */ chargen_ptr = crtc.chargen_base + crtc.chargen_rel + (crtc.raster.ycounter & 0x0f); /* pointer to current screen line */ #if CRTC_BEAM_RACING if (xs == 0) { /* When called with scr_rel = crtc.screen_rel, not prev_screen_rel */ screen_ptr = &crtc.prefetch[0]; screen_rel = xs; } else /* Uncached access; called with crtc.prev_screen_rel. */ #endif { screen_ptr = crtc.screen_base; screen_rel = scr_rel + xs; } if (crtc.crsrmode && crtc.cursor_lines && crtc.crsrstate) { /* Note: only the B series have a hardware cursor and there we have * only 1 char/cycle, so multiplying by hw_cols is not needed. */ int crsrrel = ((crtc.regs[CRTC_REG_CURSORPOSH] << 8) | crtc.regs[CRTC_REG_CURSORPOSL]) & crtc.vaddr_mask_eff; #if CRTC_BEAM_RACING if (xs == 0) { /* same condition as above */ crsrrel -= scr_rel; } #endif for (i = xs; i < xc; i++) { d = *(chargen_ptr + (screen_ptr[screen_rel & crtc.vaddr_mask_eff] << 4)); /* FIXME: mask with 0x3fff (screen_rel must be expanded) */ if (screen_rel == crsrrel) { d ^= 0xff; } screen_rel++; if (reverse_flag) { d ^= 0xff; } *pw++ = dwg_table[d >> 4]; *pw++ = dwg_table[d & 0x0f]; } } else { for (i = xs; i < xc; i++) { /* we use 16 bytes/char character generator */ d = *(chargen_ptr + (screen_ptr[screen_rel & crtc.vaddr_mask_eff] << 4)); screen_rel++; if (reverse_flag) { d ^= 0xff; } *pw++ = dwg_table[d >> 4]; *pw++ = dwg_table[d & 0x0f]; } } /* blank the rest */ for (; i < xe; i++) { *pw++ = 0; *pw++ = 0; } if (crtc.hires_draw_callback) { (crtc.hires_draw_callback)(p, xs, xc, scr_rel + xs, crtc.raster.ycounter); } } static void draw_standard_line(void) { int rl_pos = crtc.xoffset + crtc.hjitter; /* if (crtc.current_line == 1) printf("rl_pos=%d, scr_rel=%d, hw_cols=%d, rl_vis=%d, rl_len=%d\n", rl_pos, crtc.screen_rel, crtc.hw_cols, crtc.rl_visible, crtc.rl_len); */ /* FIXME: check the ends against the maximum line length */ /* the first part is left of rl_pos. Data is taken from prev. rl */ if (rl_pos > 8) { DRAW(0, rl_pos % 8, crtc.prev_screen_rel, (crtc.prev_rl_len + 1) * crtc.hw_cols - (rl_pos / 8), crtc.prev_rl_visible * crtc.hw_cols, (crtc.prev_rl_len + 1) * crtc.hw_cols); } /* this is the "normal" part of the rasterline */ DRAW(0, rl_pos, crtc.screen_rel, 0, crtc.rl_visible * crtc.hw_cols, (crtc.rl_len + 1) * crtc.hw_cols); } static void draw_reverse_line(void) { int rl_pos = crtc.xoffset + crtc.hjitter; /* the first part is left of rl_pos. Data is taken from prev. rl */ if (rl_pos > 8) { DRAW(1, rl_pos % 8, crtc.prev_screen_rel, (crtc.prev_rl_len + 1) * crtc.hw_cols - (rl_pos / 8), crtc.prev_rl_visible * crtc.hw_cols, (crtc.prev_rl_len + 1) * crtc.hw_cols); } /* this is the "normal" part of the rasterline */ DRAW(1, rl_pos, crtc.screen_rel, 0, crtc.rl_visible * crtc.hw_cols, (crtc.rl_len + 1) * crtc.hw_cols); } static int get_std_text(raster_cache_t *cache, unsigned int *xs, unsigned int *xe, int rr) { *xs = 0; *xe = (crtc.rl_len + 1) * crtc.hw_cols; return 1; } static void draw_std_text_cached(raster_cache_t *cache, unsigned int xs, unsigned int xe) { draw_standard_line(); } static int get_rev_text(raster_cache_t *cache, unsigned int *xs, unsigned int *xe, int rr) { *xs = 0; *xe = (crtc.rl_len + 1) * crtc.hw_cols; return 1; } static void draw_rev_text_cached(raster_cache_t *cache, unsigned int xs, unsigned int xe) { draw_reverse_line(); } /***************************************************************************/ static void setup_modes(void) { raster_modes_set(crtc.raster.modes, CRTC_STANDARD_MODE, get_std_text, draw_std_text_cached, draw_standard_line, draw_standard_background, NULL /* draw_std_text_foreground */ ); raster_modes_set(crtc.raster.modes, CRTC_REVERSE_MODE, get_rev_text, draw_rev_text_cached, draw_reverse_line, draw_standard_background, NULL /* draw_rev_text_foreground*/); } void crtc_draw_init(void) { init_drawing_tables(); setup_modes(); }