+
+#ifdef PNG_INFO_IMAGE_SUPPORTED
+void PNGAPI
+png_write_png(png_structrp png_ptr, png_inforp info_ptr,
+ int transforms, voidp params)
+{
+ if (png_ptr == NULL || info_ptr == NULL)
+ return;
+
+ /* Write the file header information. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* ------ these transformations don't touch the info structure ------- */
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
+ /* Invert monochrome pixels */
+ if (transforms & PNG_TRANSFORM_INVERT_MONO)
+ png_set_invert_mono(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
+ /* Shift the pixels up to a legal bit depth and fill in
+ * as appropriate to correctly scale the image.
+ */
+ if ((transforms & PNG_TRANSFORM_SHIFT)
+ && (info_ptr->valid & PNG_INFO_sBIT))
+ png_set_shift(png_ptr, &info_ptr->sig_bit);
+#endif
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
+ /* Pack pixels into bytes */
+ if (transforms & PNG_TRANSFORM_PACKING)
+ png_set_packing(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+ /* Swap location of alpha bytes from ARGB to RGBA */
+ if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+ png_set_swap_alpha(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
+ /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
+ if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
+ png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
+
+ else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#endif
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
+ /* Flip BGR pixels to RGB */
+ if (transforms & PNG_TRANSFORM_BGR)
+ png_set_bgr(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
+ /* Swap bytes of 16-bit files to most significant byte first */
+ if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+ png_set_swap(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
+ /* Swap bits of 1, 2, 4 bit packed pixel formats */
+ if (transforms & PNG_TRANSFORM_PACKSWAP)
+ png_set_packswap(png_ptr);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ /* Invert the alpha channel from opacity to transparency */
+ if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+ png_set_invert_alpha(png_ptr);
+#endif
+
+ /* ----------------------- end of transformations ------------------- */
+
+ /* Write the bits */
+ if (info_ptr->valid & PNG_INFO_IDAT)
+ png_write_image(png_ptr, info_ptr->row_pointers);
+
+ /* It is REQUIRED to call this to finish writing the rest of the file */
+ png_write_end(png_ptr, info_ptr);
+
+ PNG_UNUSED(transforms) /* Quiet compiler warnings */
+ PNG_UNUSED(params)
+}
+#endif
+
+
+#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+#ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */
+/* Initialize the write structure - general purpose utility. */
+static int
+png_image_write_init(png_imagep image)
+{
+ png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image,
+ png_safe_error, png_safe_warning);
+
+ if (png_ptr != NULL)
+ {
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+
+ if (info_ptr != NULL)
+ {
+ png_controlp control = png_voidcast(png_controlp,
+ png_malloc_warn(png_ptr, (sizeof *control)));
+
+ if (control != NULL)
+ {
+ memset(control, 0, (sizeof *control));
+
+ control->png_ptr = png_ptr;
+ control->info_ptr = info_ptr;
+ control->for_write = 1;
+
+ image->opaque = control;
+ return 1;
+ }
+
+ /* Error clean up */
+ png_destroy_info_struct(png_ptr, &info_ptr);
+ }
+
+ png_destroy_write_struct(&png_ptr, NULL);
+ }
+
+ return png_image_error(image, "png_image_write_: out of memory");
+}
+
+/* Arguments to png_image_write_main: */
+typedef struct
+{
+ /* Arguments: */
+ png_imagep image;
+ png_const_voidp buffer;
+ png_int_32 row_stride;
+ png_const_voidp colormap;
+ int convert_to_8bit;
+ /* Local variables: */
+ png_const_voidp first_row;
+ ptrdiff_t row_bytes;
+ png_voidp local_row;
+} png_image_write_control;
+
+/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to
+ * do any necessary byte swapping. The component order is defined by the
+ * png_image format value.
+ */
+static int
+png_write_image_16bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
+ png_uint_16p row_end;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+ int aindex = 0;
+ png_uint_32 y = image->height;
+
+ if (image->format & PNG_FORMAT_FLAG_ALPHA)
+ {
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+ aindex = channels;
+ }
+
+ else
+ png_error(png_ptr, "png_write_image: internal call error");
+
+ /* Work out the output row end and count over this, note that the increment
+ * above to 'row' means that row_end can actually be beyond the end of the
+ * row; this is correct.
+ */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_uint_16p out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ const png_uint_16 alpha = in_ptr[aindex];
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ out_ptr[aindex] = alpha;
+
+ /* Calculate a reciprocal. The correct calculation is simply
+ * component/alpha*65535 << 15. (I.e. 15 bits of precision); this
+ * allows correct rounding by adding .5 before the shift. 'reciprocal'
+ * is only initialized when required.
+ */
+ if (alpha > 0 && alpha < 65535)
+ reciprocal = ((0xffff<<15)+(alpha>>1))/alpha;
+
+ c = channels;
+ do /* always at least one channel */
+ {
+ png_uint_16 component = *in_ptr++;
+
+ /* The following gives 65535 for an alpha of 0, which is fine,
+ * otherwise if 0/0 is represented as some other value there is more
+ * likely to be a discontinuity which will probably damage
+ * compression when moving from a fully transparent area to a
+ * nearly transparent one. (The assumption here is that opaque
+ * areas tend not to be 0 intensity.)
+ */
+ if (component >= alpha)
+ component = 65535;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0 && alpha < 65535)
+ {
+ png_uint_32 calc = component * reciprocal;
+ calc += 16384; /* round to nearest */
+ component = (png_uint_16)(calc >> 15);
+ }
+
+ *out_ptr++ = component;
+ }
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ }
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+
+ return 1;
+}
+
+/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel
+ * is present it must be removed from the components, the components are then
+ * written in sRGB encoding. No components are added or removed.
+ *
+ * Calculate an alpha reciprocal to reverse pre-multiplication. As above the
+ * calculation can be done to 15 bits of accuracy; however, the output needs to
+ * be scaled in the range 0..255*65535, so include that scaling here.
+ */
+#define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha)
+
+static png_byte
+png_unpremultiply(png_uint_32 component, png_uint_32 alpha,
+ png_uint_32 reciprocal/*from the above macro*/)
+{
+ /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0
+ * is represented as some other value there is more likely to be a
+ * discontinuity which will probably damage compression when moving from a
+ * fully transparent area to a nearly transparent one. (The assumption here
+ * is that opaque areas tend not to be 0 intensity.)
+ *
+ * There is a rounding problem here; if alpha is less than 128 it will end up
+ * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the
+ * output change for this too.
+ */
+ if (component >= alpha || alpha < 128)
+ return 255;
+
+ /* component<alpha, so component/alpha is less than one and
+ * component*reciprocal is less than 2^31.
+ */
+ else if (component > 0)
+ {
+ /* The test is that alpha/257 (rounded) is less than 255, the first value
+ * that becomes 255 is 65407.
+ * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore,
+ * be exact!) [Could also test reciprocal != 0]
+ */
+ if (alpha < 65407)
+ {
+ component *= reciprocal;
+ component += 64; /* round to nearest */
+ component >>= 7;
+ }
+
+ else
+ component *= 255;
+
+ /* Convert the component to sRGB. */
+ return (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ else
+ return 0;
+}
+
+static int
+png_write_image_8bit(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+
+ png_const_uint_16p input_row = png_voidcast(png_const_uint_16p,
+ display->first_row);
+ png_bytep output_row = png_voidcast(png_bytep, display->local_row);
+ png_uint_32 y = image->height;
+ const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+
+ if (image->format & PNG_FORMAT_FLAG_ALPHA)
+ {
+ png_bytep row_end;
+ int aindex;
+
+ if (image->format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ aindex = -1;
+ ++input_row; /* To point to the first component */
+ ++output_row;
+ }
+
+ else
+ aindex = channels;
+
+ /* Use row_end in place of a loop counter: */
+ row_end = output_row + image->width * (channels+1);
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_16 alpha = in_ptr[aindex];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+ int c;
+
+ /* Scale and write the alpha channel. */
+ out_ptr[aindex] = alphabyte;
+
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = UNP_RECIPROCAL(alpha);
+
+ c = channels;
+ do /* always at least one channel */
+ *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal);
+ while (--c > 0);
+
+ /* Skip to next component (skip the intervening alpha channel) */
+ ++in_ptr;
+ ++out_ptr;
+ } /* while out_ptr < row_end */
+
+ png_write_row(png_ptr, png_voidcast(png_const_bytep,
+ display->local_row));
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ } /* while y */
+ }
+
+ else
+ {
+ /* No alpha channel, so the row_end really is the end of the row and it
+ * is sufficient to loop over the components one by one.
+ */
+ png_bytep row_end = output_row + image->width * channels;
+
+ while (y-- > 0)
+ {
+ png_const_uint_16p in_ptr = input_row;
+ png_bytep out_ptr = output_row;
+
+ while (out_ptr < row_end)
+ {
+ png_uint_32 component = *in_ptr++;
+
+ component *= 255;
+ *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component);
+ }
+
+ png_write_row(png_ptr, output_row);
+ input_row += display->row_bytes/(sizeof (png_uint_16));
+ }
+ }
+
+ return 1;
+}
+
+static void
+png_image_set_PLTE(png_image_write_control *display)
+{
+ const png_imagep image = display->image;
+ const void *cmap = display->colormap;
+ const int entries = image->colormap_entries > 256 ? 256 :
+ (int)image->colormap_entries;
+
+ /* NOTE: the caller must check for cmap != NULL and entries != 0 */
+ const png_uint_32 format = image->format;
+ const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
+ (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+# else
+# define afirst 0
+# endif
+
+# ifdef PNG_FORMAT_BGR_SUPPORTED
+ const int bgr = (format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
+# else
+# define bgr 0
+# endif
+
+ int i, num_trans;
+ png_color palette[256];
+ png_byte tRNS[256];
+
+ memset(tRNS, 255, (sizeof tRNS));
+ memset(palette, 0, (sizeof palette));
+
+ for (i=num_trans=0; i<entries; ++i)
+ {
+ /* This gets automatically converted to sRGB with reversal of the
+ * pre-multiplication if the color-map has an alpha channel.
+ */
+ if (format & PNG_FORMAT_FLAG_LINEAR)
+ {
+ png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
+
+ entry += i * channels;
+
+ if (channels & 1) /* no alpha */
+ {
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[(2 ^ bgr)]);
+ palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[1]);
+ palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 *
+ entry[bgr]);
+ }
+
+ else /* Gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry);
+ }
+
+ else /* alpha */
+ {
+ png_uint_16 alpha = entry[afirst ? 0 : channels-1];
+ png_byte alphabyte = (png_byte)PNG_DIV257(alpha);
+ png_uint_32 reciprocal = 0;
+
+ /* Calculate a reciprocal, as in the png_write_image_8bit code above
+ * this is designed to produce a value scaled to 255*65535 when
+ * divided by 128 (i.e. asr 7).
+ */
+ if (alphabyte > 0 && alphabyte < 255)
+ reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha;
+
+ tRNS[i] = alphabyte;
+ if (alphabyte < 255)
+ num_trans = i+1;
+
+ if (channels >= 3) /* RGB */
+ {
+ palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)],
+ alpha, reciprocal);
+ palette[i].green = png_unpremultiply(entry[afirst + 1], alpha,
+ reciprocal);
+ palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha,
+ reciprocal);
+ }
+
+ else /* gray */
+ palette[i].blue = palette[i].red = palette[i].green =
+ png_unpremultiply(entry[afirst], alpha, reciprocal);
+ }
+ }
+
+ else /* Color-map has sRGB values */
+ {
+ png_const_bytep entry = png_voidcast(png_const_bytep, cmap);
+
+ entry += i * channels;
+
+ switch (channels)
+ {
+ case 4:
+ tRNS[i] = entry[afirst ? 0 : 3];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 3:
+ palette[i].blue = entry[afirst + (2 ^ bgr)];
+ palette[i].green = entry[afirst + 1];
+ palette[i].red = entry[afirst + bgr];
+ break;
+
+ case 2:
+ tRNS[i] = entry[1 ^ afirst];
+ if (tRNS[i] < 255)
+ num_trans = i+1;
+ /* FALL THROUGH */
+ case 1:
+ palette[i].blue = palette[i].red = palette[i].green =
+ entry[afirst];
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+# ifdef afirst
+# undef afirst
+# endif
+# ifdef bgr
+# undef bgr
+# endif
+
+ png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette,
+ entries);
+
+ if (num_trans > 0)
+ png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS,
+ num_trans, NULL);
+
+ image->colormap_entries = entries;
+}
+
+static int
+png_image_write_main(png_voidp argument)
+{
+ png_image_write_control *display = png_voidcast(png_image_write_control*,
+ argument);
+ png_imagep image = display->image;
+ png_structrp png_ptr = image->opaque->png_ptr;
+ png_inforp info_ptr = image->opaque->info_ptr;
+ png_uint_32 format = image->format;
+
+ int colormap = (format & PNG_FORMAT_FLAG_COLORMAP) != 0;
+ int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */
+ int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0;
+ int write_16bit = linear && !colormap && !display->convert_to_8bit;
+
+# ifdef PNG_BENIGN_ERRORS_SUPPORTED
+ /* Make sure we error out on any bad situation */
+ png_set_benign_errors(png_ptr, 0/*error*/);
+# endif
+
+ /* Default the 'row_stride' parameter if required. */
+ if (display->row_stride == 0)
+ display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
+
+ /* Set the required transforms then write the rows in the correct order. */
+ if (format & PNG_FORMAT_FLAG_COLORMAP)
+ {
+ if (display->colormap != NULL && image->colormap_entries > 0)
+ {
+ png_uint_32 entries = image->colormap_entries;
+
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)),
+ PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_image_set_PLTE(display);
+ }
+
+ else
+ png_error(image->opaque->png_ptr,
+ "no color-map for color-mapped image");
+ }
+
+ else
+ png_set_IHDR(png_ptr, info_ptr, image->width, image->height,
+ write_16bit ? 16 : 8,
+ ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) +
+ ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0),
+ PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* Counter-intuitively the data transformations must be called *after*
+ * png_write_info, not before as in the read code, but the 'set' functions
+ * must still be called before. Just set the color space information, never
+ * write an interlaced image.
+ */
+
+ if (write_16bit)
+ {
+ /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
+
+ if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+ png_set_cHRM_fixed(png_ptr, info_ptr,
+ /* color x y */
+ /* white */ 31270, 32900,
+ /* red */ 64000, 33000,
+ /* green */ 30000, 60000,
+ /* blue */ 15000, 6000
+ );
+ }
+
+ else if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+ png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
+
+ /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
+ * space must still be gamma encoded.
+ */
+ else
+ png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
+
+ /* Write the file header. */
+ png_write_info(png_ptr, info_ptr);
+
+ /* Now set up the data transformations (*after* the header is written),
+ * remove the handled transformations from the 'format' flags for checking.
+ *
+ * First check for a little endian system if writing 16 bit files.
+ */
+ if (write_16bit)
+ {
+ PNG_CONST png_uint_16 le = 0x0001;
+
+ if (*(png_const_bytep)&le)
+ png_set_swap(png_ptr);
+ }
+
+# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
+ if (format & PNG_FORMAT_FLAG_BGR)
+ {
+ if (!colormap && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+ png_set_bgr(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_BGR;
+ }
+# endif
+
+# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+ if (format & PNG_FORMAT_FLAG_AFIRST)
+ {
+ if (!colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+ png_set_swap_alpha(png_ptr);
+ format &= ~PNG_FORMAT_FLAG_AFIRST;
+ }
+# endif
+
+ /* If there are 16 or fewer color-map entries we wrote a lower bit depth
+ * above, but the application data is still byte packed.
+ */
+ if (colormap && image->colormap_entries <= 16)
+ png_set_packing(png_ptr);
+
+ /* That should have handled all (both) the transforms. */
+ if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR |
+ PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0)
+ png_error(png_ptr, "png_write_image: unsupported transformation");
+
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
+ ptrdiff_t row_bytes = display->row_stride;
+
+ if (linear)
+ row_bytes *= (sizeof (png_uint_16));
+
+ if (row_bytes < 0)
+ row += (image->height-1) * (-row_bytes);
+
+ display->first_row = row;
+ display->row_bytes = row_bytes;
+ }
+
+ /* Apply 'fast' options if the flag is set. */
+ if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0)
+ {
+ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS);
+ /* NOTE: determined by experiment using pngstest, this reflects some
+ * balance between the time to write the image once and the time to read
+ * it about 50 times. The speed-up in pngstest was about 10-20% of the
+ * total (user) time on a heavily loaded system.
+ */
+ png_set_compression_level(png_ptr, 3);
+ }
+
+ /* Check for the cases that currently require a pre-transform on the row
+ * before it is written. This only applies when the input is 16-bit and
+ * either there is an alpha channel or it is converted to 8-bit.
+ */
+ if ((linear && alpha) || (!colormap && display->convert_to_8bit))
+ {
+ png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
+ png_get_rowbytes(png_ptr, info_ptr)));
+ int result;
+
+ display->local_row = row;
+ if (write_16bit)
+ result = png_safe_execute(image, png_write_image_16bit, display);
+ else
+ result = png_safe_execute(image, png_write_image_8bit, display);
+ display->local_row = NULL;
+
+ png_free(png_ptr, row);
+
+ /* Skip the 'write_end' on error: */
+ if (!result)
+ return 0;
+ }
+
+ /* Otherwise this is the case where the input is in a format currently
+ * supported by the rest of the libpng write code; call it directly.
+ */
+ else
+ {
+ png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
+ ptrdiff_t row_bytes = display->row_bytes;
+ png_uint_32 y = image->height;
+
+ while (y-- > 0)
+ {
+ png_write_row(png_ptr, row);
+ row += row_bytes;
+ }
+ }
+
+ png_write_end(png_ptr, info_ptr);
+ return 1;
+}
+
+int PNGAPI
+png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
+ const void *buffer, png_int_32 row_stride, const void *colormap)
+{
+ /* Write the image to the given (FILE*). */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file != NULL)
+ {
+ if (png_image_write_init(image))
+ {
+ png_image_write_control display;
+ int result;
+
+ /* This is slightly evil, but png_init_io doesn't do anything other
+ * than this and we haven't changed the standard IO functions so
+ * this saves a 'safe' function.
+ */
+ image->opaque->png_ptr->io_ptr = file;
+
+ memset(&display, 0, (sizeof display));
+ display.image = image;
+ display.buffer = buffer;
+ display.row_stride = row_stride;
+ display.colormap = colormap;
+ display.convert_to_8bit = convert_to_8bit;
+
+ result = png_safe_execute(image, png_image_write_main, &display);
+ png_image_free(image);
+ return result;
+ }
+
+ else
+ return 0;
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_stdio: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+
+int PNGAPI
+png_image_write_to_file(png_imagep image, const char *file_name,
+ int convert_to_8bit, const void *buffer, png_int_32 row_stride,
+ const void *colormap)
+{
+ /* Write the image to the named file. */
+ if (image != NULL && image->version == PNG_IMAGE_VERSION)
+ {
+ if (file_name != NULL)
+ {
+ FILE *fp = fopen(file_name, "wb");
+
+ if (fp != NULL)
+ {
+ if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
+ row_stride, colormap))
+ {
+ int error; /* from fflush/fclose */
+
+ /* Make sure the file is flushed correctly. */
+ if (fflush(fp) == 0 && ferror(fp) == 0)
+ {
+ if (fclose(fp) == 0)
+ return 1;
+
+ error = errno; /* from fclose */
+ }
+
+ else
+ {
+ error = errno; /* from fflush or ferror */
+ (void)fclose(fp);
+ }
+
+ (void)remove(file_name);
+ /* The image has already been cleaned up; this is just used to
+ * set the error (because the original write succeeded).
+ */
+ return png_image_error(image, strerror(error));
+ }
+
+ else
+ {
+ /* Clean up: just the opened file. */
+ (void)fclose(fp);
+ (void)remove(file_name);
+ return 0;
+ }
+ }
+
+ else
+ return png_image_error(image, strerror(errno));
+ }
+
+ else
+ return png_image_error(image,
+ "png_image_write_to_file: invalid argument");
+ }
+
+ else if (image != NULL)
+ return png_image_error(image,
+ "png_image_write_to_file: incorrect PNG_IMAGE_VERSION");
+
+ else
+ return 0;
+}
+#endif /* PNG_STDIO_SUPPORTED */
+#endif /* SIMPLIFIED_WRITE */
+#endif /* PNG_WRITE_SUPPORTED */
projects / wxWidgets.git / blobdiff