From 8854db3c4fc7784aef2b886bd5e5b8f893a88c2f Mon Sep 17 00:00:00 2001 From: Mark Crichton Date: Tue, 29 Jun 1999 02:36:03 +0000 Subject: [PATCH] Redid io-png for gdk-pixbuf. Note that it'll add an opaque alpha channel Redid io-png for gdk-pixbuf. Note that it'll add an opaque alpha channel to any png that doesn't have one, and will convert greyscale PNGs to RGBA. --- gdk-pixbuf/io-png.c | 168 +++++++++++++++++++++++++++++--------------- 1 file changed, 112 insertions(+), 56 deletions(-) diff --git a/gdk-pixbuf/io-png.c b/gdk-pixbuf/io-png.c index 414ef45e7..a1fef8dfb 100644 --- a/gdk-pixbuf/io-png.c +++ b/gdk-pixbuf/io-png.c @@ -1,90 +1,146 @@ /* - * io-png.c: GdkPixBuf image loader for PNG files. + * io-png.c: GdkPixBuf I/O for PNG files. * * Author: - * Miguel de Icaza (miguel@gnu.org) + * Mark Crichton * */ #include #include +#include #include "gdk-pixbuf.h" #include "gdk-pixbuf-io.h" #include /* Shared library entry point */ -GdkPixBuf * -image_load (FILE *f); +GdkPixBuf *image_load(FILE * f) { - png_structp png; - png_infop info_ptr, end_info; - int width, height, depth, color_type, interlace_type; - int have_alpha, number_passes; - art_u8 *data; - - g_return_val_if_fail (filename != NULL, NULL); + png_structp png_ptr; + png_infop info_ptr, end_info; + gint i, depth, ctype, inttype, passes; + png_uint_32 w, h, x, y; + png_bytepp rows; + art_u8 *pixels, *temp, *rowdata; + GdkPixBuf *pixbuf; - png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); - if (png) - return NULL; + g_return_val_if_fail (f != NULL, NULL); - info_ptr = png_create_info_struct (png); - if (!info_ptr){ - png_destroy_read_struct (&png, NULL, NULL); + png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, + NULL); + + info_ptr = png_create_info_struct (png_ptr); + if (!info_ptr) { + png_destroy_read_struct(&png_ptr, NULL, NULL); return NULL; } - end_info = png_create_info_struct (png); - if (!end_info){ - png_destroy_read_struct (&png, &info_ptr, NULL); - return NULL: + end_info = png_create_info_struct (png_ptr); + if (!end_info) { + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + return NULL; } - if (setjmp (png->jmpbuf)){ - png_destroy_read_struct (&png, &info_ptr, &end_info); + if (setjmp(png_ptr->jmpbuf)) { + png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); return NULL; } - png_init_io (pngptr, f); + png_init_io(png_ptr, f); + png_read_info(png_ptr, info_ptr); - png_read_info (png, info_ptr); - png_get_IHDR (png, info_ptr, &width, &height, &depth, &color_type, &interlace_type, NULL, NULL); + png_get_IHDR(png_ptr, info_ptr, &w, &h, &depth, &ctype, &inttype, + NULL, NULL); - if (color_type == color_type == PNG_COLOR_TYPE_PALETTE) - png_set_expand (png); - - /* - * Strip 16 bit information to 8 bit + /* Ok, we want to work with 24 bit images. + * However, PNG can vary depth per channel. + * So, we use the png_set_expand function to expand + * everything into a format libart expects. + * We also use png_set_strip_16 to reduce down to 8 bit/chan. */ - png_set_strip_16 (png); - /* - * Extract multiple pixels with bit depths 1, 2 and 4 from a single - * byte into separate bytes - */ - png_set_packing (png); + if (ctype == PNG_COLOR_TYPE_PALETTE && depth <= 8) + png_set_expand(png_ptr); - /* - * Makes the PNG file to be rendered into RGB or RGBA - * modes (no matter of the bit depth nor the image - * mode - */ - png_set_expand (png); + if (ctype == PNG_COLOR_TYPE_GRAY && depth < 8) + png_set_expand(png_ptr); - /* - * Simplify loading by always having 4 bytes - */ - png_set_filler (png, 0xff, PNG_FILLER_AFTER); + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) + png_set_expand(png_ptr); - if (color_type & PNG_COLOR_MASK_ALPHA) - have_alpha = 1 - else - have_alpha = 0; - - data = art_alloc (width * height * (3 + have_alpha)); - if (!data){ - png_destroy_read_struct (&png, &info_ptr, &end_info); + if (depth == 16) + png_set_strip_16(png_ptr); + + /* We also have png "packing" bits into bytes if < 8 */ + if (depth < 8) + png_set_packing(png_ptr); + + /* Add filler bits to non-alpha PNGs */ + /* make it 255, full opaque */ + if (depth == 8 && ctype == PNG_COLOR_TYPE_RGB) + png_set_filler(png_ptr, 0xFF, PNG_FILLER_AFTER); + + /* Lastly, if the PNG is greyscale, convert to RGB */ + if (ctype == PNG_COLOR_TYPE_GRAY || ctype == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + + /* ...and if we're interlaced... */ + passes = png_set_interlace_handling(png_ptr); + + /* Update our info structs */ + png_read_update_info(png_ptr, info_ptr); + + /* Allocate some memory and set up row array */ + /* This "inhales vigirously"... */ + pixels = g_malloc(w*h*4); + rows = g_malloc(h*sizeof(png_bytep)); + + if ((!pixels) || (!rows)) { + png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); return NULL; } - number_passes = png_set_interlace_handling (png); + /* Icky code, but it has to be done... */ + for (i = 0; i < h; i++) { + if ((rows[i] = g_malloc(w*sizeof(art_u8)*4)) == NULL) { + int n; + for (n = 0; n < i; n++) + g_free(rows[i]); + g_free(rows); + png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); + return NULL; + } + } + + /* And we FINALLY get here... */ + png_read_image(png_ptr, rows); + png_destroy_read_struct(&png_ptr, &info_ptr, &end_info); + + /* Now stuff the bytes into pixels & free rows[y] */ + /* RGBA order */ + temp = pixels; + for (y = 0; y < h; y++) { + (png_bytep)rowdata = rows[y]; + for (x = 0; x < w; x++) { + temp[0] = rowdata[(x*4)]; + temp[1] = rowdata[(x*4)+1]; + temp[2] = rowdata[(x*4)+2]; + temp[3] = rowdata[(x*4)+3]; + temp += 4; + } + g_free(rows[y]); + } + g_free(rows); + + /* Return the GdkPixBuf */ + pixbuf = g_new(GdkPixBuf, 1); + + pixbuf->art_pixbuf = art_pixbuf_new_rgba (pixels, w, h, (w*4)); + + /* Ok, I'm anal...shoot me */ + if (!(pixbuf->art_pixbuf)) + return NULL; + pixbuf->ref_count = 0; + pixbuf->unref_func = NULL; + + return pixbuf; } -- 2.43.2