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-rw-r--r--bmp.c72
-rw-r--r--bmp.h12
-rw-r--r--render.c66
3 files changed, 83 insertions, 67 deletions
diff --git a/bmp.c b/bmp.c
index 9537704..7ee3750 100644
--- a/bmp.c
+++ b/bmp.c
@@ -13,27 +13,33 @@
#define OFFSET_biHeight 22
#define HEADERSIZE 54
+static size_t
+bmp_calc_padding(int32_t width) {
+ return (4 - (width % 4)) % 4;
+}
+
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";
-int
-bmp_write_header(FILE* fh, int32_t width, int32_t height) {
+static int
+bmp_write_header(bmp_write_handle_t* bmph) {
char* header;
uint32_t filesize;
+ int32_t height;
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;
+ filesize = HEADERSIZE + (bmph->width * BYTES_PER_PIXEL + bmph->line_padding) * bmph->height;
+ height = -(bmph->height);
memcpy(header, header_template, HEADERSIZE);
memcpy(header + OFFSET_bfSize, &filesize, 4);
- memcpy(header + OFFSET_biWidth, &width, 4);
+ memcpy(header + OFFSET_biWidth, &(bmph->width), 4);
memcpy(header + OFFSET_biHeight, &height, 4);
- if(fwrite(header, HEADERSIZE, 1, fh) != 1) {
+ if(fwrite(header, HEADERSIZE, 1, bmph->fh) != 1) {
fprintf(stderr, "Could not write BMP header: %s\n", strerror(errno));
free(header);
return 0;
@@ -43,12 +49,62 @@ bmp_write_header(FILE* fh, int32_t width, int32_t height) {
return 1;
}
+bmp_write_handle_t*
+bmp_create(const char* fn, int32_t width, int32_t height) {
+ FILE* fh = NULL;
+ bmp_write_handle_t* rv;
+
+ if(!(fh = fopen(fn, "wb"))) {
+ return NULL;
+ }
+
+ if(!(rv = malloc(sizeof(bmp_write_handle_t)))) {
+ fclose(fh);
+ return NULL;
+ }
+
+ rv->fh = fh;
+ rv->width = width;
+ rv->height = height;
+ rv->line_left = width;
+ rv->line_padding = bmp_calc_padding(width);
+
+ if(!bmp_write_header(rv)) {
+ fclose(fh);
+ free(rv);
+ return NULL;
+ }
+
+ return rv;
+}
+
+static const char* padding = "\0\0\0\0";
+
int
-bmp_write_pixel(FILE* fh, color_t col) {
+bmp_write_pixel(bmp_write_handle_t* bmph, 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);
+ if(fwrite(pixel, 3, 1, bmph->fh) != 1) {
+ return 0;
+ }
+
+ if(--(bmph->line_left) == 0) {
+ bmph->line_left = bmph->width;
+
+ return (fwrite(padding, bmph->line_padding, 1, bmph->fh) == 1);
+ }
+
+ return 1;
+}
+
+void
+bmp_destroy(bmp_write_handle_t* bmph) {
+ if(bmph->fh) {
+ fclose(bmph->fh);
+ }
+
+ free(bmph);
}
diff --git a/bmp.h b/bmp.h
index e9b2821..89ab893 100644
--- a/bmp.h
+++ b/bmp.h
@@ -6,7 +6,15 @@
#include "color.h"
-extern int bmp_write_header(FILE* fh, int32_t width, int32_t height);
-extern int bmp_write_pixel(FILE* fh, color_t col);
+typedef struct {
+ int32_t width, height;
+ size_t line_padding;
+ size_t line_left;
+ FILE* fh;
+} bmp_write_handle_t;
+
+extern bmp_write_handle_t* bmp_create(const char* fn, int32_t width, int32_t height);
+extern int bmp_write_pixel(bmp_write_handle_t* bmph, color_t col);
+extern void bmp_destroy(bmp_write_handle_t* bmph);
#endif \ No newline at end of file
diff --git a/render.c b/render.c
index 5b3d8ca..49b0d33 100644
--- a/render.c
+++ b/render.c
@@ -6,6 +6,7 @@
#include "config.h"
#include "color.h"
+#include "bmp.h"
/* Adding submap i to all submaps > i to reconstruct the result of single buddhabrot calculations. */
static void
@@ -26,52 +27,6 @@ add_submaps(config_t* conf, uint32_t* map) {
}
}
-#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;
@@ -212,7 +167,7 @@ render(config_t* conf, uint32_t* map) {
size_t i, j;
color_t col;
double factor;
- FILE* fh = NULL;
+ bmp_write_handle_t* bmph = NULL;
size_t mapsize = conf->width * conf->height;
lookup_elem_t** lookups = NULL;
@@ -227,12 +182,9 @@ render(config_t* conf, uint32_t* map) {
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)) {
+ if(!(bmph = bmp_create(conf->output, conf->width, conf->height))) {
+ fprintf(stderr, "Could not create BMP.\n");
+ /* TODO: More details? */
goto tidyup;
}
@@ -255,8 +207,8 @@ render(config_t* conf, uint32_t* map) {
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);
+ if(!bmp_write_pixel(bmph, color_fix(col))) {
+ fputs("Could not write pixel data.\n", stderr);
goto tidyup;
}
}
@@ -264,8 +216,8 @@ render(config_t* conf, uint32_t* map) {
rv = 1;
tidyup:
- if(fh) {
- fclose(fh);
+ if(bmph) {
+ bmp_destroy(bmph);
}
if(lookups) {
for(i = 0; i < conf->iters_n; i++) {