nuclear@0: /*
nuclear@3: Copyright 2004-2012 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0: 
nuclear@1: This file is part of gbasys, a library for GameBoy Advance development.
nuclear@0: 
nuclear@0: This program is free software; you can redistribute it and/or modify
nuclear@0: it under the terms of the GNU General Public License as published by
nuclear@0: the Free Software Foundation; either version 2 of the License, or
nuclear@0: (at your option) any later version.
nuclear@0: 
nuclear@0: This program is distributed in the hope that it will be useful,
nuclear@0: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@0: GNU General Public License for more details.
nuclear@0: 
nuclear@0: You should have received a copy of the GNU General Public License
nuclear@0: along with this program; if not, write to the Free Software
nuclear@0: Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
nuclear@0: */
nuclear@0: 
nuclear@1: #include "config.h"
nuclear@0: 
nuclear@0: #include <stdlib.h>
nuclear@3: #include <string.h>
nuclear@0: #include "gfx.h"
nuclear@0: 
nuclear@0: #define FRAME_SEL_BIT	0x10
nuclear@0: 
nuclear@0: #define H_BLANK_OAM		0x20
nuclear@0: #define OBJ_MAP_2D		0x0
nuclear@0: #define OBJ_MAP_1D		0x40
nuclear@0: #define FORCE_BLANK		0x80
nuclear@0: #define BG0_ENABLE		0x100
nuclear@0: #define BG1_ENABLE		0x200
nuclear@0: #define BG2_ENABLE		0x400
nuclear@0: #define BG3_ENABLE		0x800
nuclear@0: 
nuclear@0: static volatile unsigned short *reg_disp_ctl = (void*)0x4000000;
nuclear@0: static volatile unsigned short *reg_vcount = (void*)0x4000006;
nuclear@0: 
nuclear@6: static unsigned short *paladdr = (void*)0x5000000;
nuclear@6: 
nuclear@0: static int xres, yres;
nuclear@0: static int sizeof_pixel;
nuclear@0: static int page_flipping;
nuclear@0: static int allocated_back_buffer;
nuclear@0: 
nuclear@0: static struct pixel_buffer fbuf, bbuf;
nuclear@0: struct pixel_buffer *front_buffer = &fbuf;
nuclear@0: struct pixel_buffer *back_buffer = &bbuf;
nuclear@0: 
nuclear@0: #define show_page(n)	((n) ? (*reg_disp_ctl |= FRAME_SEL_BIT) : (*reg_disp_ctl &= ~FRAME_SEL_BIT))
nuclear@0: #define swap_page()		(*reg_disp_ctl ^= FRAME_SEL_BIT)
nuclear@0: 
nuclear@0: int set_video_mode(int mode, int double_buffering) {
nuclear@0: 	if(mode < 3 || mode > 5) return -1;
nuclear@0: 
nuclear@0: 	/* mode 5: 160x128, otherwise: 240x160 */
nuclear@0: 	xres = (mode == 5) ? 160 : 240;
nuclear@0: 	yres = (mode == 5) ? 128 : 160;
nuclear@0: 
nuclear@0: 	sizeof_pixel = (mode == 4) ? 1 : 2;
nuclear@0: 
nuclear@0: 	*reg_disp_ctl = mode | BG2_ENABLE;
nuclear@0: 
nuclear@0: 	show_page(0);
nuclear@0: 
nuclear@0: 	if(allocated_back_buffer) {
nuclear@0: 		free(back_buffer->pixels);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	front_buffer->pixels = (void*)0x6000000;
nuclear@0: 	front_buffer->x = back_buffer->x = xres;
nuclear@0: 	front_buffer->y = back_buffer->y = yres;
nuclear@0: 	front_buffer->bpp = back_buffer->bpp = sizeof_pixel * 8;
nuclear@1: 
nuclear@0: 	if(mode > 3) {
nuclear@0: 		page_flipping = 1;
nuclear@0: 		back_buffer->pixels = (void*)0x600a000;
nuclear@0: 	} else {
nuclear@0: 		page_flipping = 0;
nuclear@0: 		if(double_buffering) {
nuclear@0: 			back_buffer->pixels = malloc(xres * yres * sizeof_pixel);
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void flip(void) {
nuclear@0: 	static void *tmp;
nuclear@1: 
nuclear@0: 	if(page_flipping) {
nuclear@0: 		swap_page();
nuclear@0: 		tmp = front_buffer->pixels;
nuclear@0: 		front_buffer->pixels = back_buffer->pixels;
nuclear@0: 		back_buffer->pixels = tmp;
nuclear@0: 	} else {
nuclear@0: 		/*dma_copy32(3, front_buffer->pixels, back_buffer->pixels, (xres * yres) >> 1);*/
nuclear@0: 		dma_copy32(3, front_buffer->pixels, back_buffer->pixels, 19200);
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: /* ------- pixel buffer operations ------- */
nuclear@0: 
nuclear@0: struct pixel_buffer *create_pixel_buffer(int x, int y, int bpp) {
nuclear@0: 	struct pixel_buffer *pbuf = malloc(sizeof(struct pixel_buffer));
nuclear@0: 	if(pbuf) {
nuclear@0: 		pbuf->pixels = malloc(x * y * bpp / 8);
nuclear@0: 		pbuf->x = x;
nuclear@0: 		pbuf->y = y;
nuclear@0: 		pbuf->bpp = bpp;
nuclear@0: 	}
nuclear@0: 	return pbuf;
nuclear@0: }
nuclear@0: 
nuclear@0: void destroy_pixel_buffer(struct pixel_buffer *pbuf) {
nuclear@0: 	free(pbuf->pixels);
nuclear@0: 	free(pbuf);
nuclear@0: }
nuclear@0: 
nuclear@0: void clear_buffer(struct pixel_buffer *pbuf, unsigned short color) {
nuclear@0: 	int sz = pbuf->x * pbuf->y;
nuclear@0: 
nuclear@0: 	if(pbuf->bpp == 8) {
nuclear@0: 		color |= color << 8;
nuclear@0: 		sz >>= 1;
nuclear@0: 	}
nuclear@1: 
nuclear@0: 	dma_fill16(3, pbuf->pixels, color, sz);
nuclear@0: }
nuclear@0: 
nuclear@0: void copy_buffer(const struct pixel_buffer *src, struct pixel_buffer *dst) {
nuclear@0: 	int words;
nuclear@1: 
nuclear@0: 	if(src->x != dst->x || src->y != dst->y || src->bpp != dst->bpp) return;
nuclear@0: 
nuclear@0: 	words = (src->x * src->y) >> (src->bpp == 16 ? 1 : 2);
nuclear@0: 	dma_copy32(3, dst->pixels, src->pixels, words);
nuclear@0: }
nuclear@0: 
nuclear@3: #define MIN(a, b)	((a) < (b) ? (a) : (b))
nuclear@3: 
nuclear@3: void blit(struct pixel_buffer *src, int src_x, int src_y, int src_w, int src_h,
nuclear@3: 		struct pixel_buffer *dst, int dst_x, int dst_y)
nuclear@3: {
nuclear@3: 	int i, pixsize, width, height, dstride, sstride;
nuclear@3: 	unsigned char *dptr, *sptr;
nuclear@3: 
nuclear@3: 	if(dst->bpp != src->bpp)
nuclear@3: 		return;
nuclear@3: 
nuclear@3: 	if(src_w <= 0)
nuclear@3: 		src_w = src->x;
nuclear@3: 	if(src_h <= 0)
nuclear@3: 		src_h = src->y;
nuclear@3: 
nuclear@3: 	width = MIN(src_w, MIN(src->x - src_x, dst->x - dst_x));
nuclear@3: 	height = MIN(src_h, MIN(src->y - src_y, dst->y - dst_y));
nuclear@3: 
nuclear@3: 	if(width <= 0 || height <= 0)
nuclear@3: 		return;
nuclear@3: 
nuclear@3: 	pixsize = dst->bpp / 8;
nuclear@3: 	dptr = (unsigned char*)dst->pixels + (dst_y * dst->x + dst_x) * pixsize;
nuclear@3: 	sptr = (unsigned char*)src->pixels + (src_y * src->x + src_x) * pixsize;
nuclear@3: 
nuclear@3: 	dstride = dst->x * pixsize;
nuclear@3: 	sstride = src->x * pixsize;
nuclear@3: 
nuclear@3: 	for(i=0; i<height; i++) {
nuclear@3: 		memcpy(dptr, sptr, width * pixsize);
nuclear@3: 		sptr += sstride;
nuclear@3: 		dptr += dstride;
nuclear@3: 	}
nuclear@3: }
nuclear@3: 
nuclear@6: void set_palette(int idx, int r, int g, int b)
nuclear@6: {
nuclear@6: 	paladdr[idx] = RGB(r, g, b);
nuclear@6: }
nuclear@0: 
nuclear@0: void draw_line(int x1, int y1, int x2, int y2, unsigned short col, struct pixel_buffer *pbuf) {
nuclear@0: 	int dx, dy, dx2, dy2;
nuclear@0: 	int x_inc, y_inc;
nuclear@0: 	int error;
nuclear@0: 	int i;
nuclear@0: 	unsigned short *ptr = pbuf->pixels;
nuclear@0: 
nuclear@0: 	ptr += y1 * pbuf->x + x1;
nuclear@0: 	dx = x2 - x1;
nuclear@0: 	dy = y2 - y1;
nuclear@1: 
nuclear@0: 	if(dx >= 0) {
nuclear@0: 		x_inc = 1;
nuclear@0: 	} else {
nuclear@0: 		x_inc = -1;
nuclear@0: 		dx = -dx;
nuclear@0: 	}
nuclear@1: 
nuclear@0: 	if(dy >= 0) {
nuclear@0: 		y_inc = pbuf->x;
nuclear@0: 	} else {
nuclear@0: 		y_inc = -pbuf->x;
nuclear@0: 		dy = -dy;
nuclear@0: 	}
nuclear@1: 
nuclear@0: 	dx2 = dx << 1;
nuclear@0: 	dy2 = dy << 1;
nuclear@0: 
nuclear@0: 	if(dx > dy) {
nuclear@0: 		error = dy2 - dx;
nuclear@0: 		for(i=0; i<=dx; i++) {
nuclear@0: 			*ptr = col;
nuclear@0: 			if(error >= 0) {
nuclear@0: 				error -= dx2;
nuclear@0: 				ptr += y_inc;
nuclear@0: 			}
nuclear@0: 			error += dy2;
nuclear@0: 			ptr += x_inc;
nuclear@0: 		}
nuclear@0: 	} else {
nuclear@0: 		error = dx2 - dy;
nuclear@0: 		for(i=0;i<=dy;i++) {
nuclear@0: 			*ptr = col;
nuclear@0: 			if(error >= 0) {
nuclear@0: 				error -= dy2;
nuclear@0: 				ptr += x_inc;
nuclear@0: 			}
nuclear@0: 			error += dx2;
nuclear@0: 			ptr += y_inc;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: }