diff options
Diffstat (limited to 'render.c')
| -rw-r--r-- | render.c | 278 |
1 files changed, 276 insertions, 2 deletions
@@ -1,12 +1,286 @@ #include <stdio.h> #include <stdlib.h> #include <stdint.h> +#include <errno.h> +#include <string.h> #include "config.h" #include "color.h" +/* Adding submap i to all submaps > i to reconstruct the result of single buddhabrot calculations. */ +static void +add_submaps(config_t* conf, uint32_t* map) { + int i, j; + size_t k, mapsize, off_i, off_j; + + mapsize = conf->width * conf->height; + + for(i = conf->iters_n - 1; i <= 0; i--) { + off_i = mapsize * i; + for(j = 0; j < i; j++) { + off_j = mapsize * j; + for(k = 0; k < mapsize; k++) { + map[off_i + k] += map[off_j + k]; + } + } + } +} + +#define BYTES_PER_PIXEL 3 +#define OFFSET_bfSize 2 +#define OFFSET_biWidth 18 +#define OFFSET_biHeight 22 +#define HEADERSIZE 54 + +static const char* header_template = "BM \0\0\0\0\x36\0\0\0\x28\0\0\0 \x01\0\x18\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; + +static int +bmp_write_header(FILE* fh, int32_t width, int32_t height) { + char* header; + uint32_t filesize; + + if(!(header = malloc(HEADERSIZE))) { + fputs("Could not allocate memory for BMP header.\n", stderr); + return 0; + } + + filesize = HEADERSIZE + (width * height * BYTES_PER_PIXEL); + height *= -1; + + memcpy(header, header_template, HEADERSIZE); + memcpy(header + OFFSET_bfSize, &filesize, 4); + memcpy(header + OFFSET_biWidth, &width, 4); + memcpy(header + OFFSET_biHeight, &height, 4); + + if(fwrite(header, HEADERSIZE, 1, fh) != 1) { + fprintf(stderr, "Could not write BMP header: %s\n", strerror(errno)); + free(header); + return 0; + } + + free(header); + return 1; +} + +static int +bmp_write_pixel(FILE* fh, color_t col) { + uint8_t pixel[3]; + pixel[0] = col.b; + pixel[1] = col.g; + pixel[2] = col.r; + + return (fwrite(pixel, 3, 1, fh) == 1); +} + +typedef struct lookup_elem_t { + uint32_t val; + struct lookup_elem_t* prev; + struct lookup_elem_t* next; +} lookup_elem_t; + +static lookup_elem_t* +new_lookup_elem(uint32_t val, lookup_elem_t* prev, lookup_elem_t* next) { + lookup_elem_t* rv = malloc(sizeof(lookup_elem_t)); + if(!rv) { + return NULL; + } + + rv->val = val; + rv->prev = prev; + rv->next = next; + + return rv; +} + +static int +maybe_insert(uint32_t val, lookup_elem_t* a, lookup_elem_t* b) { + lookup_elem_t* new; + + if(!(new = new_lookup_elem(val, a, b))) { + return 0; + } + + if(!a) { + b->prev = new; + return 1; + } + if(!b) { + a->next = new; + return 1; + } + + if((a->val < val) && (val < b->val)) { + a->next = new; + b->prev = new; + } else { + free(new); + } + return 1; +} + +static int +build_lookup(uint32_t* map, size_t mapsize, lookup_elem_t** e) { + size_t i; + uint32_t val; + + for(i = 0; i < mapsize; i++) { + val = map[i]; + + if(!*e) { + if(!(*e = new_lookup_elem(val, NULL, NULL))) { + return 0; + } + continue; + } + + for(;;) { + if((*e)->val == val) { + break; + } + + if(val > (*e)->val) { + if(!maybe_insert(val, *e, (*e)->next)) { + return 0; + } + *e = (*e)->next; + } else { + if(!maybe_insert(val, (*e)->prev, *e)) { + return 0; + } + *e = (*e)->prev; + } + } + } + + while((*e)->prev) { + *e = (*e)->prev; + } + + return 1; +} + +static size_t +lookup_len(lookup_elem_t* e) { + size_t len; + + if(!e) { + return 0; + } + + while(e->prev) { + e = e->prev; + } + + len = 0; + while(e) { + len++; + e = e->next; + } + return len; +} + +static void +lookup_destroy(lookup_elem_t* e) { + lookup_elem_t* next; + while(e->prev) { + e = e->prev; + } + while(e) { + next = e->next; + free(e); + e = next; + } +} + +static size_t +lookup(uint32_t val, lookup_elem_t** e, size_t* pos) { + while((*e)->val != val) { + if(val < (*e)->val) { + *e = (*e)->prev; + (*pos)--; + } else { + *e = (*e)->next; + (*pos)++; + } + } + return *pos; +} + int render(config_t* conf, uint32_t* map) { - /* TODO */ - return 1; + int rv = 0; + size_t i, j; + color_t col; + double factor; + FILE* fh = NULL; + size_t mapsize = conf->width * conf->height; + + lookup_elem_t** lookups = NULL; + size_t* poss = NULL; + size_t* lens = NULL; + + lookups = calloc(sizeof(lookup_elem_t*), conf->iters_n); + poss = calloc(sizeof(size_t), conf->iters_n); + lens = calloc(sizeof(size_t), conf->iters_n); + if((!lookups) || (!poss) || (!lens)) { + fputs("Could not allocate memory for lookup tables.\n", stderr); + goto tidyup; + } + + if(!(fh = fopen(conf->output, "wb"))) { + fprintf(stderr, "Could not open output file '%s': %s\n", conf->output, strerror(errno)); + goto tidyup; + } + + if(!bmp_write_header(fh, conf->width, conf->height)) { + goto tidyup; + } + + add_submaps(conf, map); + + for(i = 0; i < conf->iters_n; i++) { + if(!build_lookup(map+(mapsize*i), mapsize, &(lookups[i]))) { + fputs("Could not build lookup table.\n", stderr); + goto tidyup; + } + lens[i] = lookup_len(lookups[i]); + } + + for(i = 0; i < mapsize; i++) { + col.r = 0; + col.g = 0; + col.b = 0; + + for(j = 0; j < conf->iters_n; j++) { + factor = (double) lookup(map[i + mapsize * j], &(lookups[j]), &(poss[j])) / (double) lens[j]; + col = color_add(col, color_mul(conf->colors[j], factor)); + } + if(!bmp_write_pixel(fh, color_fix(col))) { + fputs("Could not write pixel data.", stderr); + goto tidyup; + } + } + + rv = 1; + +tidyup: + if(fh) { + fclose(fh); + } + if(lookups) { + for(i = 0; i < conf->iters_n; i++) { + if(lookups[i]) { + lookup_destroy(lookups[i]); + } + } + free(lookups); + } + if(poss) { + free(poss); + } + if(lens) { + free(lens); + } + + return rv; } |