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poppler/poppler-0.12.3-downscale.patch

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diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index 9a0f3be..42ac3a8 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -58,6 +58,7 @@
#include <splash/SplashBitmap.h>
#include "CairoOutputDev.h"
#include "CairoFontEngine.h"
+#include "CairoRescaleBox.h"
//------------------------------------------------------------------------
// #define LOG_CAIRO
@@ -1331,6 +1332,82 @@ void CairoOutputDev::endMaskClip(GfxState *state) {
clearSoftMask(state);
}
+cairo_surface_t *CairoOutputDev::downscaleSurface(cairo_surface_t *orig_surface) {
+ cairo_surface_t *dest_surface;
+ unsigned char *dest_buffer;
+ int dest_stride;
+ unsigned char *orig_buffer;
+ int orig_width, orig_height;
+ int orig_stride;
+ GBool res;
+
+ if (printing)
+ return NULL;
+
+ cairo_matrix_t matrix;
+ cairo_get_matrix(cairo, &matrix);
+
+ /* this whole computation should be factored out */
+ double xScale = matrix.xx;
+ double yScale = matrix.yy;
+ int tx, tx2, ty, ty2; /* the integer co-oridinates of the resulting image */
+ int scaledHeight;
+ int scaledWidth;
+ if (xScale >= 0) {
+ tx = splashRound(matrix.x0 - 0.01);
+ tx2 = splashRound(matrix.x0 + xScale + 0.01) - 1;
+ } else {
+ tx = splashRound(matrix.x0 + 0.01) - 1;
+ tx2 = splashRound(matrix.x0 + xScale - 0.01);
+ }
+ scaledWidth = abs(tx2 - tx) + 1;
+ //scaledWidth = splashRound(fabs(xScale));
+ if (scaledWidth == 0) {
+ // technically, this should draw nothing, but it generally seems
+ // better to draw a one-pixel-wide stripe rather than throwing it
+ // away
+ scaledWidth = 1;
+ }
+ if (yScale >= 0) {
+ ty = splashFloor(matrix.y0 + 0.01);
+ ty2 = splashCeil(matrix.y0 + yScale - 0.01);
+ } else {
+ ty = splashCeil(matrix.y0 - 0.01);
+ ty2 = splashFloor(matrix.y0 + yScale + 0.01);
+ }
+ scaledHeight = abs(ty2 - ty);
+ if (scaledHeight == 0) {
+ scaledHeight = 1;
+ }
+
+ orig_width = cairo_image_surface_get_width (orig_surface);
+ orig_height = cairo_image_surface_get_height (orig_surface);
+ if (scaledWidth >= orig_width || scaledHeight >= orig_height)
+ return NULL;
+
+ dest_surface = cairo_surface_create_similar (orig_surface,
+ cairo_surface_get_content (orig_surface),
+ scaledWidth, scaledHeight);
+ dest_buffer = cairo_image_surface_get_data (dest_surface);
+ dest_stride = cairo_image_surface_get_stride (dest_surface);
+
+ orig_buffer = cairo_image_surface_get_data (orig_surface);
+ orig_stride = cairo_image_surface_get_stride (orig_surface);
+
+ res = downscale_box_filter((uint32_t *)orig_buffer,
+ orig_stride, orig_width, orig_height,
+ scaledWidth, scaledHeight, 0, 0,
+ scaledWidth, scaledHeight,
+ (uint32_t *)dest_buffer, dest_stride);
+ if (!res) {
+ cairo_surface_destroy (dest_surface);
+ return NULL;
+ }
+
+ return dest_surface;
+
+}
+
void CairoOutputDev::drawImageMask(GfxState *state, Object *ref, Stream *str,
int width, int height, GBool invert,
GBool interpolate, GBool inlineImg) {
@@ -2094,6 +2171,18 @@ void CairoOutputDev::drawImage(GfxState *state, Object *ref, Stream *str,
}
gfree(lookup);
+ cairo_surface_t *scaled_surface;
+
+ scaled_surface = downscaleSurface (image);
+ if (scaled_surface) {
+ if (cairo_surface_status (scaled_surface))
+ goto cleanup;
+ cairo_surface_destroy (image);
+ image = scaled_surface;
+ width = cairo_image_surface_get_width (image);
+ height = cairo_image_surface_get_height (image);
+ }
+
cairo_surface_mark_dirty (image);
pattern = cairo_pattern_create_for_surface (image);
cairo_surface_destroy (image);
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index fb9c0d7..266f0cb 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -268,6 +268,7 @@ public:
protected:
void doPath(cairo_t *cairo, GfxState *state, GfxPath *path);
+ cairo_surface_t *downscaleSurface(cairo_surface_t *orig_surface);
GfxRGB fill_color, stroke_color;
cairo_pattern_t *fill_pattern, *stroke_pattern;
diff --git a/poppler/CairoRescaleBox.cc b/poppler/CairoRescaleBox.cc
new file mode 100644
index 0000000..dce5ddd
--- /dev/null
+++ b/poppler/CairoRescaleBox.cc
@@ -0,0 +1,352 @@
+/* -*- Mode: c; c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t; -*- */
+/*
+ * Copyright © 2009 Mozilla Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Mozilla Corporation not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission. Mozilla Corporation makes no
+ * representations about the suitability of this software for any purpose. It
+ * is provided "as is" without express or implied warranty.
+ *
+ * MOZILLA CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT
+ * SHALL MOZILLA CORPORATION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ *
+ * Author: Jeff Muizelaar, Mozilla Corp.
+ */
+
+/* This implements a box filter that supports non-integer box sizes */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdint.h>
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <math.h>
+#include "goo/gmem.h"
+#include "CairoRescaleBox.h"
+
+typedef unsigned short int uint16_t;
+typedef unsigned int uint32_t;
+
+/* we work in fixed point where 1. == 1 << 24 */
+#define FIXED_SHIFT 24
+
+static void downsample_row_box_filter (
+ int start, int width,
+ uint32_t *src, uint32_t *dest,
+ int coverage[], int pixel_coverage)
+{
+ /* we need an array of the pixel contribution of each destination pixel on the boundaries.
+ * we invert the value to get the value on the other size of the box */
+ /*
+
+ value = a * contribution * 1/box_size
+ value += a * 1/box_size
+ value += a * 1/box_size
+ value += a * 1/box_size
+ value += a * (1 - contribution) * 1/box_size
+ a * (1/box_size - contribution * 1/box_size)
+
+ box size is constant
+
+
+ value = a * contribtion_a * 1/box_size + b * contribution_b * 1/box_size
+ contribution_b = (1 - contribution_a)
+ = (1 - contribution_a_next)
+ */
+
+ /* box size = ceil(src_width/dest_width) */
+ int x = 0;
+
+ /* skip to start */
+ /* XXX: it might be possible to do this directly instead of iteratively, however
+ * the iterative solution is simple */
+ while (x < start)
+ {
+ int box = 1 << FIXED_SHIFT;
+ int start_coverage = coverage[x];
+ box -= start_coverage;
+ src++;
+ while (box >= pixel_coverage)
+ {
+ src++;
+ box -= pixel_coverage;
+ }
+ x++;
+ }
+
+ while (x < start + width)
+ {
+ uint32_t a = 0;
+ uint32_t r = 0;
+ uint32_t g = 0;
+ uint32_t b = 0;
+ int box = 1 << FIXED_SHIFT;
+ int start_coverage = coverage[x];
+
+ a = ((*src >> 24) & 0xff) * start_coverage;
+ r = ((*src >> 16) & 0xff) * start_coverage;
+ g = ((*src >> 8) & 0xff) * start_coverage;
+ b = ((*src >> 0) & 0xff) * start_coverage;
+ src++;
+ x++;
+ box -= start_coverage;
+
+ while (box >= pixel_coverage)
+ {
+ a += ((*src >> 24) & 0xff) * pixel_coverage;
+ r += ((*src >> 16) & 0xff) * pixel_coverage;
+ g += ((*src >> 8) & 0xff) * pixel_coverage;
+ b += ((*src >> 0) & 0xff) * pixel_coverage;
+ src++;
+
+ box -= pixel_coverage;
+ }
+
+ /* multiply by whatever is leftover
+ * this ensures that we don't bias down.
+ * i.e. start_coverage + n*pixel_coverage + box == 1 << 24 */
+ if (box > 0)
+ {
+ a += ((*src >> 24) & 0xff) * box;
+ r += ((*src >> 16) & 0xff) * box;
+ g += ((*src >> 8) & 0xff) * box;
+ b += ((*src >> 0) & 0xff) * box;
+ }
+
+ a >>= FIXED_SHIFT;
+ r >>= FIXED_SHIFT;
+ g >>= FIXED_SHIFT;
+ b >>= FIXED_SHIFT;
+
+ *dest = (a << 24) | (r << 16) | (g << 8) | b;
+ dest++;
+ }
+}
+
+static void downsample_columns_box_filter (
+ int n,
+ int start_coverage,
+ int pixel_coverage,
+ uint32_t *src, uint32_t *dest)
+{
+ int stride = n;
+ while (n--) {
+ uint32_t a = 0;
+ uint32_t r = 0;
+ uint32_t g = 0;
+ uint32_t b = 0;
+ uint32_t *column_src = src;
+ int box = 1 << FIXED_SHIFT;
+
+ a = ((*column_src >> 24) & 0xff) * start_coverage;
+ r = ((*column_src >> 16) & 0xff) * start_coverage;
+ g = ((*column_src >> 8) & 0xff) * start_coverage;
+ b = ((*column_src >> 0) & 0xff) * start_coverage;
+ column_src += stride;
+ box -= start_coverage;
+
+ while (box >= pixel_coverage)
+ {
+ a += ((*column_src >> 24) & 0xff) * pixel_coverage;
+ r += ((*column_src >> 16) & 0xff) * pixel_coverage;
+ g += ((*column_src >> 8) & 0xff) * pixel_coverage;
+ b += ((*column_src >> 0) & 0xff) * pixel_coverage;
+ column_src += stride;
+ box -= pixel_coverage;
+ }
+
+ if (box > 0) {
+ a += ((*column_src >> 24) & 0xff) * box;
+ r += ((*column_src >> 16) & 0xff) * box;
+ g += ((*column_src >> 8) & 0xff) * box;
+ b += ((*column_src >> 0) & 0xff) * box;
+ }
+
+ a >>= FIXED_SHIFT;
+ r >>= FIXED_SHIFT;
+ g >>= FIXED_SHIFT;
+ b >>= FIXED_SHIFT;
+
+ *dest = (a << 24) | (r << 16) | (g << 8) | b;
+ dest++;
+ src++;
+ }
+}
+
+static int compute_coverage (int coverage[], int src_length, int dest_length)
+{
+ int i;
+ /* num = src_length/dest_length
+ total = sum(pixel) / num
+
+ pixel * 1/num == pixel * dest_length / src_length
+ */
+ /* the average contribution of each source pixel */
+ int ratio = ((1 << 24)*(long long int)dest_length)/src_length;
+ /* because ((1 << 24)*(long long int)dest_length) won't always be divisible by src_length
+ * we'll need someplace to put the other bits.
+ *
+ * We want to ensure a + n*ratio < 1<<24
+ *
+ * 1<<24
+ * */
+
+ double scale = (double)src_length/dest_length;
+
+ /* for each destination pixel compute the coverage of the left most pixel included in the box */
+ /* I have a proof of this, which this margin is too narrow to contain */
+ for (i=0; i<dest_length; i++)
+ {
+ float left_side = i*scale;
+ float right_side = (i+1)*scale;
+ float right_fract = right_side - floor (right_side);
+ float left_fract = ceil (left_side) - left_side;
+ int overage;
+ /* find out how many source pixels will be used to fill the box */
+ int count = floor (right_side) - ceil (left_side);
+ /* what's the maximum value this expression can become?
+ floor((i+1)*scale) - ceil(i*scale)
+
+ (i+1)*scale - i*scale == scale
+
+ since floor((i+1)*scale) <= (i+1)*scale
+ and ceil(i*scale) >= i*scale
+
+ floor((i+1)*scale) - ceil(i*scale) <= scale
+
+ further since: floor((i+1)*scale) - ceil(i*scale) is an integer
+
+ therefore:
+ floor((i+1)*scale) - ceil(i*scale) <= floor(scale)
+ */
+
+ if (left_fract == 0.)
+ count--;
+
+ /* compute how much the right-most pixel contributes */
+ overage = ratio*(right_fract);
+
+ /* the remainder is the the amount that the left-most pixel
+ * contributes */
+ coverage[i] = (1<<24) - (count * ratio + overage);
+ }
+
+ return ratio;
+}
+
+GBool downscale_box_filter(uint32_t *orig, int orig_stride, unsigned orig_width, unsigned orig_height,
+ signed scaled_width, signed scaled_height,
+ uint16_t start_column, uint16_t start_row,
+ uint16_t width, uint16_t height,
+ uint32_t *dest, int dst_stride)
+{
+ int pixel_coverage_x, pixel_coverage_y;
+ int dest_y;
+ int src_y = 0;
+ uint32_t *scanline = orig;
+ int *x_coverage = NULL;
+ int *y_coverage = NULL;
+ uint32_t *temp_buf = NULL;
+ GBool retval = gFalse;
+
+ x_coverage = (int *)gmallocn3 (orig_width, 1, sizeof(int));
+ y_coverage = (int *)gmallocn3 (orig_height, 1, sizeof(int));
+
+ /* we need to allocate enough room for ceil(src_height/dest_height)+1
+ Example:
+ src_height = 140
+ dest_height = 50
+ src_height/dest_height = 2.8
+
+ |-------------| 2.8 pixels
+ |----|----|----|----| 4 pixels
+ need to sample 3 pixels
+
+ |-------------| 2.8 pixels
+ |----|----|----|----| 4 pixels
+ need to sample 4 pixels
+ */
+
+ temp_buf = (uint32_t *)gmallocn3 ((orig_height + scaled_height-1)/scaled_height+1, scaled_width, sizeof(uint32_t));
+
+ if (!x_coverage || !y_coverage || !scanline || !temp_buf)
+ goto cleanup;
+
+ pixel_coverage_x = compute_coverage (x_coverage, orig_width, scaled_width);
+ pixel_coverage_y = compute_coverage (y_coverage, orig_height, scaled_height);
+
+ assert (width + start_column <= scaled_width);
+
+ /* skip the rows at the beginning */
+ for (dest_y = 0; dest_y < start_row; dest_y++)
+ {
+ int box = 1 << FIXED_SHIFT;
+ int start_coverage_y = y_coverage[dest_y];
+ box -= start_coverage_y;
+ src_y++;
+ while (box >= pixel_coverage_y)
+ {
+ box -= pixel_coverage_y;
+ src_y++;
+ }
+ }
+
+ for (; dest_y < start_row + height; dest_y++)
+ {
+ int columns = 0;
+ int box = 1 << FIXED_SHIFT;
+ int start_coverage_y = y_coverage[dest_y];
+
+ scanline = orig + src_y * orig_stride / 4;
+ downsample_row_box_filter (start_column, width, scanline, temp_buf + width * columns, x_coverage, pixel_coverage_x);
+ columns++;
+ src_y++;
+ box -= start_coverage_y;
+
+ while (box >= pixel_coverage_y)
+ {
+ scanline = orig + src_y * orig_stride / 4;
+ downsample_row_box_filter (start_column, width, scanline, temp_buf + width * columns, x_coverage, pixel_coverage_x);
+ columns++;
+ src_y++;
+ box -= pixel_coverage_y;
+ }
+
+ /* downsample any leftovers */
+ if (box > 0)
+ {
+ scanline = orig + src_y * orig_stride / 4;
+ downsample_row_box_filter (start_column, width, scanline, temp_buf + width * columns, x_coverage, pixel_coverage_x);
+ columns++;
+ }
+
+ /* now scale the rows we just downsampled in the y direction */
+ downsample_columns_box_filter (width, start_coverage_y, pixel_coverage_y, temp_buf, dest);
+ dest += dst_stride / 4;
+
+// assert(width*columns <= ((orig_height + scaled_height-1)/scaled_height+1) * width);
+ }
+// assert (src_y<=orig_height);
+
+ retval = gTrue;
+
+cleanup:
+ free (x_coverage);
+ free (y_coverage);
+ free (temp_buf);
+
+ return gTrue;
+}
diff --git a/poppler/CairoRescaleBox.h b/poppler/CairoRescaleBox.h
new file mode 100644
index 0000000..5349c87
--- /dev/null
+++ b/poppler/CairoRescaleBox.h
@@ -0,0 +1,12 @@
+#ifndef CAIRO_RESCALE_BOX_H
+#define CAIRO_RESCALE_BOX_H
+
+#include "goo/gtypes.h"
+
+GBool downscale_box_filter(unsigned int *orig, int orig_stride, unsigned orig_width, unsigned orig_height,
+ signed scaled_width, signed scaled_height,
+ unsigned short int start_column, unsigned short int start_row,
+ unsigned short int width, unsigned short int height,
+ unsigned int *dest, int dst_stride);
+
+#endif /* CAIRO_RESCALE_BOX_H */
diff --git a/poppler/Makefile.am b/poppler/Makefile.am
index ec79e31..096ea76 100644
--- a/poppler/Makefile.am
+++ b/poppler/Makefile.am
@@ -47,7 +47,9 @@ libpoppler_cairo_la_SOURCES = \
CairoFontEngine.cc \
CairoFontEngine.h \
CairoOutputDev.cc \
- CairoOutputDev.h
+ CairoOutputDev.h \
+ CairoRescaleBox.cc \
+ CairoRescaleBox.h
endif
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