started adding indexed color support to imago2

[dos_imgv] / imago / src / imago2.c

diff --git a/imago/src/imago2.c b/imago/src/imago2.c
index b4ec465..2480f82 100644 (file)
--- a/imago/src/imago2.c
+++ b/imago/src/imago2.c
@@ -21,8 +21,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <string.h>
 #include "imago2.h"
 #include "ftmodule.h"
+#include "byteord.h"
 #include "chkalloc.h"
 
+/* calculate int-aligned offset to colormap, right after the end of the pixel data */
+#define CMAPPTR(fb, fbsz)      \
+       (struct img_colormap*)((((uintptr_t)fb) + (fbsz) + sizeof(int) - 1) & ~(sizeof(int) - 1))
+
 static int pixel_size(enum img_fmt fmt);
 static size_t def_read(void *buf, size_t bytes, void *uptr);
 static size_t def_write(void *buf, size_t bytes, void *uptr);
@@ -94,15 +99,21 @@ int img_set_pixels(struct img_pixmap *img, int w, int h, enum img_fmt fmt, void
 {
        void *newpix;
        int pixsz = pixel_size(fmt);
+       int bsz = w * h * pixsz;
+
+       if(fmt == IMG_FMT_IDX8) {
+               /* add space for the colormap, and space to align it to sizeof(int) */
+               bsz += sizeof(struct img_colormap) + sizeof(int) - 1;
+       }
 
-       if(!(newpix = chk_malloc(w * h * pixsz))) {
+       if(!(newpix = chk_malloc(bsz))) {
                return -1;
        }
 
        if(pix) {
                memcpy(newpix, pix, w * h * pixsz);
        } else {
-               memset(newpix, 0, w * h * pixsz);
+               memset(newpix, 0, bsz);
        }
 
        chk_free(img->pixels);
@@ -397,6 +408,17 @@ void img_getpixel4f(struct img_pixmap *img, int x, int y, float *r, float *g, fl
        }
 }
 
+struct img_colormap *img_colormap(struct img_pixmap *img)
+{
+       int cmap_offs;
+
+       if(img->fmt != IMG_FMT_IDX8 || !img->pixels) {
+               return 0;
+       }
+
+       return CMAPPTR(img->pixels, img->width * img->height * img->pixelsz);
+}
+
 void img_io_set_user_data(struct img_io *io, void *uptr)
 {
        io->uptr = uptr;
@@ -422,6 +444,7 @@ static int pixel_size(enum img_fmt fmt)
 {
        switch(fmt) {
        case IMG_FMT_GREY8:
+       case IMG_FMT_IDX8:
                return 1;
        case IMG_FMT_RGB24:
                return 3;