gbasys

annotate src/gfx.c @ 3:06726f0b8cd3

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author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 08 Mar 2012 14:37:17 +0200
parents c50064b181c2
children f77381b12726
rev   line source
nuclear@0 1 /*
nuclear@3 2 Copyright 2004-2012 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0 3
nuclear@1 4 This file is part of gbasys, a library for GameBoy Advance development.
nuclear@0 5
nuclear@0 6 This program is free software; you can redistribute it and/or modify
nuclear@0 7 it under the terms of the GNU General Public License as published by
nuclear@0 8 the Free Software Foundation; either version 2 of the License, or
nuclear@0 9 (at your option) any later version.
nuclear@0 10
nuclear@0 11 This program is distributed in the hope that it will be useful,
nuclear@0 12 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@0 14 GNU General Public License for more details.
nuclear@0 15
nuclear@0 16 You should have received a copy of the GNU General Public License
nuclear@0 17 along with this program; if not, write to the Free Software
nuclear@0 18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
nuclear@0 19 */
nuclear@0 20
nuclear@1 21 #include "config.h"
nuclear@0 22
nuclear@0 23 #include <stdlib.h>
nuclear@3 24 #include <string.h>
nuclear@0 25 #include "gfx.h"
nuclear@0 26
nuclear@0 27 #define FRAME_SEL_BIT 0x10
nuclear@0 28
nuclear@0 29 #define H_BLANK_OAM 0x20
nuclear@0 30 #define OBJ_MAP_2D 0x0
nuclear@0 31 #define OBJ_MAP_1D 0x40
nuclear@0 32 #define FORCE_BLANK 0x80
nuclear@0 33 #define BG0_ENABLE 0x100
nuclear@0 34 #define BG1_ENABLE 0x200
nuclear@0 35 #define BG2_ENABLE 0x400
nuclear@0 36 #define BG3_ENABLE 0x800
nuclear@0 37
nuclear@0 38 static volatile unsigned short *reg_disp_ctl = (void*)0x4000000;
nuclear@0 39 static volatile unsigned short *reg_vcount = (void*)0x4000006;
nuclear@0 40
nuclear@0 41 static int xres, yres;
nuclear@0 42 static int sizeof_pixel;
nuclear@0 43 static int page_flipping;
nuclear@0 44 static int allocated_back_buffer;
nuclear@0 45
nuclear@0 46 static struct pixel_buffer fbuf, bbuf;
nuclear@0 47 struct pixel_buffer *front_buffer = &fbuf;
nuclear@0 48 struct pixel_buffer *back_buffer = &bbuf;
nuclear@0 49
nuclear@0 50 #define show_page(n) ((n) ? (*reg_disp_ctl |= FRAME_SEL_BIT) : (*reg_disp_ctl &= ~FRAME_SEL_BIT))
nuclear@0 51 #define swap_page() (*reg_disp_ctl ^= FRAME_SEL_BIT)
nuclear@0 52
nuclear@0 53 int set_video_mode(int mode, int double_buffering) {
nuclear@0 54 if(mode < 3 || mode > 5) return -1;
nuclear@0 55
nuclear@0 56 /* mode 5: 160x128, otherwise: 240x160 */
nuclear@0 57 xres = (mode == 5) ? 160 : 240;
nuclear@0 58 yres = (mode == 5) ? 128 : 160;
nuclear@0 59
nuclear@0 60 sizeof_pixel = (mode == 4) ? 1 : 2;
nuclear@0 61
nuclear@0 62 *reg_disp_ctl = mode | BG2_ENABLE;
nuclear@0 63
nuclear@0 64 show_page(0);
nuclear@0 65
nuclear@0 66 if(allocated_back_buffer) {
nuclear@0 67 free(back_buffer->pixels);
nuclear@0 68 }
nuclear@0 69
nuclear@0 70 front_buffer->pixels = (void*)0x6000000;
nuclear@0 71 front_buffer->x = back_buffer->x = xres;
nuclear@0 72 front_buffer->y = back_buffer->y = yres;
nuclear@0 73 front_buffer->bpp = back_buffer->bpp = sizeof_pixel * 8;
nuclear@1 74
nuclear@0 75 if(mode > 3) {
nuclear@0 76 page_flipping = 1;
nuclear@0 77 back_buffer->pixels = (void*)0x600a000;
nuclear@0 78 } else {
nuclear@0 79 page_flipping = 0;
nuclear@0 80 if(double_buffering) {
nuclear@0 81 back_buffer->pixels = malloc(xres * yres * sizeof_pixel);
nuclear@0 82 }
nuclear@0 83 }
nuclear@0 84 }
nuclear@0 85
nuclear@0 86 void flip(void) {
nuclear@0 87 static void *tmp;
nuclear@1 88
nuclear@0 89 if(page_flipping) {
nuclear@0 90 swap_page();
nuclear@0 91 tmp = front_buffer->pixels;
nuclear@0 92 front_buffer->pixels = back_buffer->pixels;
nuclear@0 93 back_buffer->pixels = tmp;
nuclear@0 94 } else {
nuclear@0 95 /*dma_copy32(3, front_buffer->pixels, back_buffer->pixels, (xres * yres) >> 1);*/
nuclear@0 96 dma_copy32(3, front_buffer->pixels, back_buffer->pixels, 19200);
nuclear@0 97 }
nuclear@0 98 }
nuclear@0 99
nuclear@0 100 /* ------- pixel buffer operations ------- */
nuclear@0 101
nuclear@0 102 struct pixel_buffer *create_pixel_buffer(int x, int y, int bpp) {
nuclear@0 103 struct pixel_buffer *pbuf = malloc(sizeof(struct pixel_buffer));
nuclear@0 104 if(pbuf) {
nuclear@0 105 pbuf->pixels = malloc(x * y * bpp / 8);
nuclear@0 106 pbuf->x = x;
nuclear@0 107 pbuf->y = y;
nuclear@0 108 pbuf->bpp = bpp;
nuclear@0 109 }
nuclear@0 110 return pbuf;
nuclear@0 111 }
nuclear@0 112
nuclear@0 113 void destroy_pixel_buffer(struct pixel_buffer *pbuf) {
nuclear@0 114 free(pbuf->pixels);
nuclear@0 115 free(pbuf);
nuclear@0 116 }
nuclear@0 117
nuclear@0 118 void clear_buffer(struct pixel_buffer *pbuf, unsigned short color) {
nuclear@0 119 int sz = pbuf->x * pbuf->y;
nuclear@0 120
nuclear@0 121 if(pbuf->bpp == 8) {
nuclear@0 122 color |= color << 8;
nuclear@0 123 sz >>= 1;
nuclear@0 124 }
nuclear@1 125
nuclear@0 126 dma_fill16(3, pbuf->pixels, color, sz);
nuclear@0 127 }
nuclear@0 128
nuclear@0 129 void copy_buffer(const struct pixel_buffer *src, struct pixel_buffer *dst) {
nuclear@0 130 int words;
nuclear@1 131
nuclear@0 132 if(src->x != dst->x || src->y != dst->y || src->bpp != dst->bpp) return;
nuclear@0 133
nuclear@0 134 words = (src->x * src->y) >> (src->bpp == 16 ? 1 : 2);
nuclear@0 135 dma_copy32(3, dst->pixels, src->pixels, words);
nuclear@0 136 }
nuclear@0 137
nuclear@3 138 #define MIN(a, b) ((a) < (b) ? (a) : (b))
nuclear@3 139
nuclear@3 140 void blit(struct pixel_buffer *src, int src_x, int src_y, int src_w, int src_h,
nuclear@3 141 struct pixel_buffer *dst, int dst_x, int dst_y)
nuclear@3 142 {
nuclear@3 143 int i, pixsize, width, height, dstride, sstride;
nuclear@3 144 unsigned char *dptr, *sptr;
nuclear@3 145
nuclear@3 146 if(dst->bpp != src->bpp)
nuclear@3 147 return;
nuclear@3 148
nuclear@3 149 if(src_w <= 0)
nuclear@3 150 src_w = src->x;
nuclear@3 151 if(src_h <= 0)
nuclear@3 152 src_h = src->y;
nuclear@3 153
nuclear@3 154 width = MIN(src_w, MIN(src->x - src_x, dst->x - dst_x));
nuclear@3 155 height = MIN(src_h, MIN(src->y - src_y, dst->y - dst_y));
nuclear@3 156
nuclear@3 157 if(width <= 0 || height <= 0)
nuclear@3 158 return;
nuclear@3 159
nuclear@3 160 pixsize = dst->bpp / 8;
nuclear@3 161 dptr = (unsigned char*)dst->pixels + (dst_y * dst->x + dst_x) * pixsize;
nuclear@3 162 sptr = (unsigned char*)src->pixels + (src_y * src->x + src_x) * pixsize;
nuclear@3 163
nuclear@3 164 dstride = dst->x * pixsize;
nuclear@3 165 sstride = src->x * pixsize;
nuclear@3 166
nuclear@3 167 for(i=0; i<height; i++) {
nuclear@3 168 memcpy(dptr, sptr, width * pixsize);
nuclear@3 169 sptr += sstride;
nuclear@3 170 dptr += dstride;
nuclear@3 171 }
nuclear@3 172 }
nuclear@3 173
nuclear@0 174
nuclear@0 175 void draw_line(int x1, int y1, int x2, int y2, unsigned short col, struct pixel_buffer *pbuf) {
nuclear@0 176 int dx, dy, dx2, dy2;
nuclear@0 177 int x_inc, y_inc;
nuclear@0 178 int error;
nuclear@0 179 int i;
nuclear@0 180 unsigned short *ptr = pbuf->pixels;
nuclear@0 181
nuclear@0 182 ptr += y1 * pbuf->x + x1;
nuclear@0 183 dx = x2 - x1;
nuclear@0 184 dy = y2 - y1;
nuclear@1 185
nuclear@0 186 if(dx >= 0) {
nuclear@0 187 x_inc = 1;
nuclear@0 188 } else {
nuclear@0 189 x_inc = -1;
nuclear@0 190 dx = -dx;
nuclear@0 191 }
nuclear@1 192
nuclear@0 193 if(dy >= 0) {
nuclear@0 194 y_inc = pbuf->x;
nuclear@0 195 } else {
nuclear@0 196 y_inc = -pbuf->x;
nuclear@0 197 dy = -dy;
nuclear@0 198 }
nuclear@1 199
nuclear@0 200 dx2 = dx << 1;
nuclear@0 201 dy2 = dy << 1;
nuclear@0 202
nuclear@0 203 if(dx > dy) {
nuclear@0 204 error = dy2 - dx;
nuclear@0 205 for(i=0; i<=dx; i++) {
nuclear@0 206 *ptr = col;
nuclear@0 207 if(error >= 0) {
nuclear@0 208 error -= dx2;
nuclear@0 209 ptr += y_inc;
nuclear@0 210 }
nuclear@0 211 error += dy2;
nuclear@0 212 ptr += x_inc;
nuclear@0 213 }
nuclear@0 214 } else {
nuclear@0 215 error = dx2 - dy;
nuclear@0 216 for(i=0;i<=dy;i++) {
nuclear@0 217 *ptr = col;
nuclear@0 218 if(error >= 0) {
nuclear@0 219 error -= dy2;
nuclear@0 220 ptr += x_inc;
nuclear@0 221 }
nuclear@0 222 error += dx2;
nuclear@0 223 ptr += y_inc;
nuclear@0 224 }
nuclear@0 225 }
nuclear@0 226 }