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authorTor Andersson <tor.andersson@artifex.com>2011-04-04 18:08:53 +0200
committerTor Andersson <tor.andersson@artifex.com>2011-04-04 18:08:53 +0200
commitc8d226b5bfb5dab2db10ea5175966de7bac9640e (patch)
tree982435a97942aeaf6a527eb3a07ac2c5242aaa9b /draw/imagesmooth.c
parent53faeef5a0f2e352cc89b1695ec1db1eda85e707 (diff)
downloadmupdf-c8d226b5bfb5dab2db10ea5175966de7bac9640e.tar.xz
draw: Rename files in draw directory.
Diffstat (limited to 'draw/imagesmooth.c')
-rw-r--r--draw/imagesmooth.c1175
1 files changed, 0 insertions, 1175 deletions
diff --git a/draw/imagesmooth.c b/draw/imagesmooth.c
deleted file mode 100644
index 6254e3e4..00000000
--- a/draw/imagesmooth.c
+++ /dev/null
@@ -1,1175 +0,0 @@
-/*
-This code does smooth scaling of a pixmap.
-
-This function returns a new pixmap representing the area starting at (0,0)
-given by taking the source pixmap src, scaling it to width w, and height h,
-and then positioning it at (frac(x),frac(y)).
-*/
-
-#include "fitz.h"
-
-/* Do we special case handling of single pixel high/wide images? The
- * 'purest' handling is given by not special casing them, but certain
- * files that use such images 'stack' them to give full images. Not
- * special casing them results in then being fainter and giving noticable
- * rounding errors.
- */
-#define SINGLE_PIXEL_SPECIALS
-
-#ifdef DEBUG_SCALING
-#ifdef WIN32
-#include <windows.h>
-static void debug_print(const char *fmt, ...)
-{
- va_list args;
- char text[256];
- va_start(args, fmt);
- vsprintf(text, fmt, args);
- va_end(args);
- OutputDebugStringA(text);
- printf(text);
-}
-#else
-static void debug_print(const char *fmt, ...)
-{
- va_list args;
- va_start(args, fmt);
- vfprintf(stderr, fmt, args);
- va_end(args);
-}
-#endif
-#endif
-#ifdef DEBUG_SCALING
-#define DBUG(A) debug_print A
-#else
-#define DBUG(A) do {} while(0==1)
-#endif
-
-/*
-Consider a row of source samples, src, of width src_w, positioned at x,
-scaled to width dst_w.
-
-src[i] is centred at: x + (i + 0.5)*dst_w/src_w
-
-Therefore the distance between the centre of the jth output pixel and
-the centre of the ith source sample is:
-
-dist[j,i] = j + 0.5 - (x + (i + 0.5)*dst_w/src_w)
-
-When scaling up, therefore:
-
-dst[j] = SUM(filter(dist[j,i]) * src[i])
- (for all ints i)
-
-This can be simplified by noticing that filters are only non zero within
-a given filter width (henceforth called W). So:
-
-dst[j] = SUM(filter(dist[j,i]) * src[i])
- (for ints i, s.t. (j*src_w/dst_w)-W < i < (j*src_w/dst_w)+W)
-
-When scaling down, each filtered source sample is stretched to be wider
-to avoid aliasing issues. This effectively reduces the distance between
-centres.
-
-dst[j] = SUM(filter(dist[j,i] * F) * F * src[i])
- (where F = dst_w/src_w)
- (for ints i, s.t. (j-W)/F < i < (j+W)/F)
-
-*/
-
-typedef struct fz_scalefilter_s fz_scalefilter;
-
-struct fz_scalefilter_s
-{
- int width;
- float (*fn)(fz_scalefilter *, float);
-};
-
-/* Image scale filters */
-
-static float
-triangle(fz_scalefilter *filter, float f)
-{
- if (f >= 1)
- return 0;
- return 1-f;
-}
-
-static float
-box(fz_scalefilter *filter, float f)
-{
- if (f >= 0.5f)
- return 0;
- return 1;
-}
-
-static float
-simple(fz_scalefilter *filter, float x)
-{
- if (x >= 1)
- return 0;
- return 1 + (2*x - 3)*x*x;
-}
-
-static float
-lanczos2(fz_scalefilter *filter, float x)
-{
- if (x >= 2)
- return 0;
- return sinf(M_PI*x) * sinf(M_PI*x/2) / (M_PI*x) / (M_PI*x/2);
-}
-
-static float
-lanczos3(fz_scalefilter *filter, float f)
-{
- if (f >= 3)
- return 0;
- return sinf(M_PI*f) * sinf(M_PI*f/3) / (M_PI*f) / (M_PI*f/3);
-}
-
-/*
-The Mitchell family of filters is defined:
-
- f(x) = 1 { (12-9B-6C)x^3 + (-18+12B+6C)x^2 + (6-2B) for x < 1
- - {
- 6 { (-B-6C)x^3+(6B+30C)x^2+(-12B-48C)x+(8B+24C) for 1<=x<=2
-
-The 'best' ones lie along the line B+2C = 1.
-The literature suggests that B=1/3, C=1/3 is best.
-
- f(x) = 1 { (12-3-2)x^3 - (-18+4+2)x^2 + (16/3) for x < 1
- - {
- 6 { (-7/3)x^3 + 12x^2 - 20x + (32/3) for 1<=x<=2
-
- f(x) = 1 { 21x^3 - 36x^2 + 16 for x < 1
- - {
- 18{ -7x^3 + 36x^2 - 60x + 32 for 1<=x<=2
-*/
-
-static float
-mitchell(fz_scalefilter *filter, float x)
-{
- if (x >= 2)
- return 0;
- if (x >= 1)
- return (32 + x*(-60 + x*(36 - 7*x)))/18;
- return (16 + x*x*(-36 + 21*x))/18;
-}
-
-fz_scalefilter fz_scalefilter_box = { 1, box };
-fz_scalefilter fz_scalefilter_triangle = { 1, triangle };
-fz_scalefilter fz_scalefilter_simple = { 1, simple };
-fz_scalefilter fz_scalefilter_lanczos2 = { 2, lanczos2 };
-fz_scalefilter fz_scalefilter_lanczos3 = { 3, lanczos3 };
-fz_scalefilter fz_scalefilter_mitchell = { 2, mitchell };
-
-/*
-We build ourselves a set of tables to contain the precalculated weights
-for a given set of scale settings.
-
-The first dst_w entries in index are the index into index of the
-sets of weight for each destination pixel.
-
-Each of the sets of weights is a set of values consisting of:
- the minimum source pixel index used for this destination pixel
- the number of weights used for this destination pixel
- the weights themselves
-
-So to calculate dst[i] we do the following:
-
- weights = &index[index[i]];
- min = *weights++;
- len = *weights++;
- dst[i] = 0;
- while (--len > 0)
- dst[i] += src[min++] * *weights++
-
-in addition, we guarantee that at the end of this process weights will now
-point to the weights value for dst pixel i+1.
-
-In the simplest version of this algorithm, we would scale the whole image
-horizontally first into a temporary buffer, then scale that temporary
-buffer again vertically to give us our result. Using such a simple
-algorithm would mean that could use the same style of weights for both
-horizontal and vertical scaling.
-
-Unfortunately, this would also require a large temporary buffer,
-particularly in the case where we are scaling up.
-
-We therefore modify the algorithm as follows; we scale scanlines from the
-source image horizontally into a temporary buffer, until we have all the
-contributors for a given output scanline. We then produce that output
-scanline from the temporary buffer. In this way we restrict the height
-of the temporary buffer to a small fraction of the final size.
-
-Unfortunately, this means that the pseudo code for recombining a
-scanline of fully scaled pixels is as follows:
-
- weights = &index[index[y]];
- min = *weights++;
- len = *weights++;
- for (x=0 to dst_w)
- min2 = min
- len2 = len
- weights2 = weights
- dst[x] = 0;
- while (--len2 > 0)
- dst[x] += temp[x][(min2++) % tmp_buf_height] * *weights2++
-
-i.e. it requires a % operation for every source pixel - this is typically
-expensive.
-
-To avoid this, we alter the order in which vertical weights are stored,
-so that they are ordered in the same order as the temporary buffer lines
-would appear. This simplifies the algorithm to:
-
- weights = &index[index[y]];
- min = *weights++;
- len = *weights++;
- for (x=0 to dst_w)
- min2 = 0
- len2 = len
- weights2 = weights
- dst[x] = 0;
- while (--len2 > 0)
- dst[x] += temp[i][min2++] * *weights2++
-
-This means that len may be larger than it needs to be (due to the
-possible inclusion of a zero weight row or two), but in practise this
-is only an increase of 1 or 2 at worst.
-
-We implement this by generating the weights as normal (but ensuring we
-leave enough space) and then reordering afterwards.
-
-*/
-
-typedef struct fz_weights_s fz_weights;
-
-struct fz_weights_s
-{
- int count;
- int max_len;
- int n;
- int flip;
- int new_line;
- int index[1];
-};
-
-static fz_weights *
-newweights(fz_scalefilter *filter, int src_w, float dst_w, int dst_w_i, int n, int flip)
-{
- int max_len;
- fz_weights *weights;
-
- if (src_w > dst_w)
- {
- /* Scaling down, so there will be a maximum of
- * 2*filterwidth*src_w/dst_w src pixels
- * contributing to each dst pixel. */
- max_len = (int)ceilf((2 * filter->width * src_w)/dst_w);
- if (max_len > src_w)
- max_len = src_w;
- }
- else
- {
- /* Scaling up, so there will be a maximum of
- * 2*filterwidth src pixels contributing to each dst pixel.
- */
- max_len = 2 * filter->width;
- }
- /* We need the size of the struct,
- * plus dst_w*sizeof(int) for the index
- * plus (2+max_len)*sizeof(int) for the weights
- * plus room for an extra set of weights for reordering.
- */
- weights = fz_malloc(sizeof(*weights)+(max_len+3)*(dst_w_i+1)*sizeof(int));
- if (weights == NULL)
- return NULL;
- weights->count = -1;
- weights->max_len = max_len;
- weights->index[0] = dst_w_i;
- weights->n = n;
- weights->flip = flip;
- return weights;
-}
-
-static void
-init_weights(fz_weights *weights, int j)
-{
- int index;
-
- assert(weights->count == j-1);
- weights->count++;
- weights->new_line = 1;
- if (j == 0)
- index = weights->index[0];
- else
- {
- index = weights->index[j-1];
- index += 2 + weights->index[index+1];
- }
- weights->index[j] = index; /* row pointer */
- weights->index[index] = 0; /* min */
- weights->index[index+1] = 0; /* len */
-}
-
-static void
-add_weight(fz_weights *weights, int j, int i, fz_scalefilter *filter,
- float x, float F, float G, int src_w, float dst_w)
-{
- float dist = j - x + 0.5f - ((i + 0.5f)*dst_w/src_w);
- float f;
- int min, len, index, weight;
-
- dist *= G;
- if (dist < 0)
- dist = -dist;
- f = filter->fn(filter, dist)*F;
- weight = (int)(256*f+0.5f);
- if (weight == 0)
- return;
-
- /* wrap i back into range */
-#ifdef MIRROR_WRAP
- do
- {
- if (i < 0)
- i = -1-i;
- else if (i >= src_w)
- i = 2*src_w-1-i;
- else
- break;
- }
- while (1);
-#elif defined(WRAP)
- if (i < 0)
- i = 0;
- else if (i >= src_w)
- i = src_w-1;
-#else
- if (i < 0)
- {
- i = 0;
- weight = 0;
- }
- else if (i >= src_w)
- {
- i = src_w-1;
- weight = 0;
- }
-#endif
-
- DBUG(("add_weight[%d][%d] = %d(%g) dist=%g\n",j,i,weight,f,dist));
-
- if (weights->new_line)
- {
- /* New line */
- weights->new_line = 0;
- index = weights->index[j]; /* row pointer */
- weights->index[index] = i; /* min */
- weights->index[index+1] = 0; /* len */
- }
- index = weights->index[j];
- min = weights->index[index++];
- len = weights->index[index++];
- while (i < min)
- {
- /* This only happens in rare cases, but we need to insert
- * one earlier. In exceedingly rare cases we may need to
- * insert more than one earlier. */
- int k;
-
- for (k = len; k > 0; k--)
- {
- weights->index[index+k] = weights->index[index+k-1];
- }
- weights->index[index] = 0;
- min--;
- len++;
- weights->index[index-2] = min;
- weights->index[index-1] = len;
- }
- if (i-min >= len)
- {
- /* The usual case */
- while (i-min >= ++len)
- {
- weights->index[index+len-1] = 0;
- }
- assert(len-1 == i-min);
- weights->index[index+i-min] = weight;
- weights->index[index-1] = len;
- assert(len <= weights->max_len);
- }
- else
- {
- /* Infrequent case */
- weights->index[index+i-min] += weight;
- }
-}
-
-static void
-reorder_weights(fz_weights *weights, int j, int src_w)
-{
- int idx = weights->index[j];
- int min = weights->index[idx++];
- int len = weights->index[idx++];
- int max = weights->max_len;
- int tmp = idx+max;
- int i, off;
-
- /* Copy into the temporary area */
- memcpy(&weights->index[tmp], &weights->index[idx], sizeof(int)*len);
-
- /* Pad out if required */
- assert(len <= max);
- assert(min+len <= src_w);
- off = 0;
- if (len < max)
- {
- memset(&weights->index[tmp+len], 0, sizeof(int)*(max-len));
- len = max;
- if (min + len > src_w)
- {
- off = min + len - src_w;
- min = src_w - len;
- weights->index[idx-2] = min;
- }
- weights->index[idx-1] = len;
- }
-
- /* Copy back into the proper places */
- for (i = 0; i < len; i++)
- {
- weights->index[idx+((min+i+off) % max)] = weights->index[tmp+i];
- }
-}
-
-static void
-check_weights(fz_weights *weights, int j, int w)
-{
- int idx, len;
- int sum = 0;
- int max = -256;
- int maxidx = 0;
- int i;
-
- idx = weights->index[j];
- idx++; /* min */
- len = weights->index[idx++];
-
- for(i=0; i < len; i++)
- {
- int v = weights->index[idx++];
- sum += v;
- if (v > max)
- {
- max = v;
- maxidx = idx;
- }
- }
- if (((j != 0) && (j != w-1)) || (sum > 256))
- weights->index[maxidx-1] += 256-sum;
- DBUG(("total weight %d = %d\n", j, sum));
-}
-
-static fz_weights *
-make_weights(int src_w, float x, float dst_w, fz_scalefilter *filter, int vertical, int dst_w_int, int n, int flip)
-{
- fz_weights *weights;
- float F, G;
- float window;
- int j;
-
- if (dst_w < src_w)
- {
- /* Scaling down */
- F = dst_w / src_w;
- G = 1;
- }
- else
- {
- /* Scaling up */
- F = 1;
- G = src_w / dst_w;
- }
- window = filter->width / F;
- DBUG(("make_weights src_w=%d x=%g dst_w=%g dst_w_int=%d F=%g window=%g\n", src_w, x, dst_w, dst_w_int, F, window));
- weights = newweights(filter, src_w, dst_w, dst_w_int, n, flip);
- if (weights == NULL)
- return NULL;
- for (j = 0; j < dst_w_int; j++)
- {
- /* find the position of the centre of dst[j] in src space */
- float centre = (j - x + 0.5f)*src_w/dst_w - 0.5f;
- int l, r;
- l = ceilf(centre - window);
- r = floorf(centre + window);
- DBUG(("%d: centre=%g l=%d r=%d\n", j, centre, l, r));
- init_weights(weights, j);
- for (; l <= r; l++)
- {
- add_weight(weights, j, l, filter, x, F, G, src_w, dst_w);
- }
- check_weights(weights, j, dst_w_int);
- if (vertical)
- {
- reorder_weights(weights, j, src_w);
- }
- }
- weights->count++; /* weights->count = dst_w_int now */
- return weights;
-}
-
-static void
-scale_row_to_temp(int *dst, unsigned char *src, fz_weights *weights)
-{
- int *contrib = &weights->index[weights->index[0]];
- int len, i, j, n;
- unsigned char *min;
-
- n = weights->n;
- if (weights->flip)
- {
- dst += (weights->count-1)*n;
- for (i=weights->count; i > 0; i--)
- {
- min = &src[n * *contrib++];
- len = *contrib++;
- for (j = 0; j < n; j++)
- dst[j] = 0;
- while (len-- > 0)
- {
- for (j = n; j > 0; j--)
- *dst++ += *min++ * *contrib;
- dst -= n;
- contrib++;
- }
- dst -= n;
- }
- }
- else
- {
- for (i=weights->count; i > 0; i--)
- {
- min = &src[n * *contrib++];
- len = *contrib++;
- for (j = 0; j < n; j++)
- dst[j] = 0;
- while (len-- > 0)
- {
- for (j = n; j > 0; j--)
- *dst++ += *min++ * *contrib;
- dst -= n;
- contrib++;
- }
- dst += n;
- }
- }
-}
-
-static void
-scale_row_to_temp1(int *dst, unsigned char *src, fz_weights *weights)
-{
- int *contrib = &weights->index[weights->index[0]];
- int len, i;
- unsigned char *min;
-
- assert(weights->n == 1);
- if (weights->flip)
- {
- dst += weights->count;
- for (i=weights->count; i > 0; i--)
- {
- int val = 0;
- min = &src[*contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- val += *min++ * *contrib++;
- }
- *--dst = val;
- }
- }
- else
- {
- for (i=weights->count; i > 0; i--)
- {
- int val = 0;
- min = &src[*contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- val += *min++ * *contrib++;
- }
- *dst++ = val;
- }
- }
-}
-
-static void
-scale_row_to_temp2(int *dst, unsigned char *src, fz_weights *weights)
-{
- int *contrib = &weights->index[weights->index[0]];
- int len, i;
- unsigned char *min;
-
- assert(weights->n == 2);
- if (weights->flip)
- {
- dst += 2*weights->count;
- for (i=weights->count; i > 0; i--)
- {
- int c1 = 0;
- int c2 = 0;
- min = &src[2 * *contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- c1 += *min++ * *contrib;
- c2 += *min++ * *contrib++;
- }
- *--dst = c2;
- *--dst = c1;
- }
- }
- else
- {
- for (i=weights->count; i > 0; i--)
- {
- int c1 = 0;
- int c2 = 0;
- min = &src[2 * *contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- c1 += *min++ * *contrib;
- c2 += *min++ * *contrib++;
- }
- *dst++ = c1;
- *dst++ = c2;
- }
- }
-}
-
-static void
-scale_row_to_temp4(int *dst, unsigned char *src, fz_weights *weights)
-{
- int *contrib = &weights->index[weights->index[0]];
-#ifndef ARCH_ARM
- int len, i;
- unsigned char *min;
-#endif
-
- assert(weights->n == 4);
- if (weights->flip)
- {
- dst += 4*weights->count;
-#ifdef ARCH_ARM
- asm volatile(
- "1:"
- "ldr r4, [%2], #4 @ r4 = *contrib++ \n"
- "ldr r9, [%2], #4 @ r9 = len = *contrib++ \n"
- "mov r5, #0 @ r5 = r = 0 \n"
- "mov r6, #0 @ r6 = g = 0 \n"
- "mov r7, #0 @ r7 = b = 0 \n"
- "mov r8, #0 @ r8 = a = 0 \n"
- "add r4, %1, r4, LSL #2 @ r4 = min = &src[4*r4] \n"
- "cmp r9, #0 @ while (len-- > 0) \n"
- "beq 3f @ { \n"
- "2: \n"
- "ldr r10,[%2], #4 @ r10 = *contrib++ \n"
- "ldrb r11,[r4], #1 @ r11 = *min++ \n"
- "ldrb r12,[r4], #1 @ r12 = *min++ \n"
- "ldrb r14,[r4], #1 @ r14 = *min++ \n"
- "mla r5, r10,r11,r5 @ r += r11 * r10 \n"
- "ldrb r11,[r4], #1 @ r11 = *min++ \n"
- "mla r6, r10,r12,r6 @ g += r12 * r10 \n"
- "mla r7, r10,r14,r7 @ b += r14 * r10 \n"
- "mla r8, r10,r11,r8 @ a += r11 * r10 \n"
- "subs r9, r9, #1 @ r9 = len-- \n"
- "bgt 2b @ } \n"
- "stmdb %0!,{r5,r6,r7,r8} @ *--dst=a;*--dst=b; \n"
- "3: @ *--dst=g;*--dst=r; \n"
- "subs %3, %3, #1 @ i-- \n"
- "bgt 1b @ \n"
- :
- :
- "r" (dst),
- "r" (src),
- "r" (contrib),
- "r" (weights->count)
- :
- "r4","r5","r6","r7","r8","r9","r10","r11","r12","r14",
- "memory","cc"
- );
-#else
- for (i=weights->count; i > 0; i--)
- {
- int r = 0;
- int g = 0;
- int b = 0;
- int a = 0;
- min = &src[4 * *contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- r += *min++ * *contrib;
- g += *min++ * *contrib;
- b += *min++ * *contrib;
- a += *min++ * *contrib++;
- }
- *--dst = a;
- *--dst = b;
- *--dst = g;
- *--dst = r;
- }
-#endif
- }
- else
- {
-#ifdef ARCH_ARM
- asm volatile(
- "1:"
- "ldr r4, [%2], #4 @ r4 = *contrib++ \n"
- "ldr r9, [%2], #4 @ r9 = len = *contrib++ \n"
- "mov r5, #0 @ r5 = r = 0 \n"
- "mov r6, #0 @ r6 = g = 0 \n"
- "mov r7, #0 @ r7 = b = 0 \n"
- "mov r8, #0 @ r8 = a = 0 \n"
- "add r4, %1, r4, LSL #2 @ r4 = min = &src[4*r4] \n"
- "cmp r9, #0 @ while (len-- > 0) \n"
- "beq 3f @ { \n"
- "2: \n"
- "ldr r10,[%2], #4 @ r10 = *contrib++ \n"
- "ldrb r11,[r4], #1 @ r11 = *min++ \n"
- "ldrb r12,[r4], #1 @ r12 = *min++ \n"
- "ldrb r14,[r4], #1 @ r14 = *min++ \n"
- "mla r5, r10,r11,r5 @ r += r11 * r10 \n"
- "ldrb r11,[r4], #1 @ r11 = *min++ \n"
- "mla r6, r10,r12,r6 @ g += r12 * r10 \n"
- "mla r7, r10,r14,r7 @ b += r14 * r10 \n"
- "mla r8, r10,r11,r8 @ a += r11 * r10 \n"
- "subs r9, r9, #1 @ r9 = len-- \n"
- "bgt 2b @ } \n"
- "stmia %0!,{r5,r6,r7,r8} @ *dst++=r;*dst++=g; \n"
- "3: @ *dst++=b;*dst++=a; \n"
- "subs %3, %3, #1 @ i-- \n"
- "bgt 1b @ \n"
- :
- :
- "r" (dst),
- "r" (src),
- "r" (contrib),
- "r" (weights->count)
- :
- "r4","r5","r6","r7","r8","r9","r10","r11","r12","r14",
- "memory","cc"
- );
-#else
- for (i=weights->count; i > 0; i--)
- {
- int r = 0;
- int g = 0;
- int b = 0;
- int a = 0;
- min = &src[4 * *contrib++];
- len = *contrib++;
- while (len-- > 0)
- {
- r += *min++ * *contrib;
- g += *min++ * *contrib;
- b += *min++ * *contrib;
- a += *min++ * *contrib++;
- }
- *dst++ = r;
- *dst++ = g;
- *dst++ = b;
- *dst++ = a;
- }
-#endif
- }
-}
-
-static void
-scale_row_from_temp(unsigned char *dst, int *src, fz_weights *weights, int width, int row)
-{
- int *contrib = &weights->index[weights->index[row]];
- int len, x;
-
- contrib++; /* Skip min */
- len = *contrib++;
- for (x=width; x > 0; x--)
- {
- int *min = src;
- int val = 0;
- int len2 = len;
- int *contrib2 = contrib;
-
- while (len2-- > 0)
- {
- val += *min * *contrib2++;
- min += width;
- }
- val = (val+(1<<15))>>16;
- if (val < 0)
- val = 0;
- else if (val > 255)
- val = 255;
- *dst++ = val;
- src++;
- }
-}
-
-#ifdef SINGLE_PIXEL_SPECIALS
-static void
-duplicate_single_pixel(unsigned char *dst, unsigned char *src, int n, int w, int h)
-{
- int i;
-
- for (i = n; i > 0; i--)
- *dst++ = *src++;
- for (i = (w*h-1)*n; i > 0; i--)
- {
- *dst = dst[-n];
- dst++;
- }
-}
-
-static void
-scale_single_row(unsigned char *dst, unsigned char *src, fz_weights *weights, int src_w, int h)
-{
- int *contrib = &weights->index[weights->index[0]];
- int min, len, i, j, val, n;
- int tmp[FZ_MAXCOLORS];
-
- n = weights->n;
- /* Scale a single row */
- if (weights->flip)
- {
- dst += (weights->count-1)*n;
- for (i=weights->count; i > 0; i--)
- {
- min = *contrib++;
- len = *contrib++;
- min *= n;
- for (j = 0; j < n; j++)
- tmp[j] = 0;
- while (len-- > 0)
- {
- for (j = 0; j < n; j++)
- tmp[j] += src[min++] * *contrib;
- contrib++;
- }
- for (j = 0; j < n; j++)
- {
- val = (tmp[j]+(1<<7))>>8;
- if (val < 0)
- val = 0;
- else if (val > 255)
- val = 255;
- *dst++ = val;
- }
- dst -= 2*n;
- }
- dst += n;
- }
- else
- {
- for (i=weights->count; i > 0; i--)
- {
- min = *contrib++;
- len = *contrib++;
- min *= n;
- for (j = 0; j < n; j++)
- tmp[j] = 0;
- while (len-- > 0)
- {
- for (j = 0; j < n; j++)
- tmp[j] += src[min++] * *contrib;
- contrib++;
- }
- for (j = 0; j < n; j++)
- {
- val = (tmp[j]+(1<<7))>>8;
- if (val < 0)
- val = 0;
- else if (val > 255)
- val = 255;
- *dst++ = val;
- }
- }
- }
- /* And then duplicate it h times */
- n *= weights->count;
- while (--h > 0)
- {
- memcpy(dst, dst-n, n);
- dst += n;
- }
-}
-
-static void
-scale_single_col(unsigned char *dst, unsigned char *src, fz_weights *weights, int src_w, int n, int w, int flip_y)
-{
- int *contrib = &weights->index[weights->index[0]];
- int min, len, i, j, val;
- int tmp[FZ_MAXCOLORS];
-
- if (flip_y)
- {
- src_w = (src_w-1)*n;
- w = (w-1)*n;
- for (i=weights->count; i > 0; i--)
- {
- /* Scale the next pixel in the column */
- min = *contrib++;
- len = *contrib++;
- min = src_w-min*n;
- for (j = 0; j < n; j++)
- tmp[j] = 0;
- while (len-- > 0)
- {
- for (j = 0; j < n; j++)
- tmp[j] += src[src_w-min+j] * *contrib;
- contrib++;
- }
- for (j = 0; j < n; j++)
- {
- val = (tmp[j]+(1<<7))>>8;
- if (val < 0)
- val = 0;
- else if (val > 255)
- val = 255;
- *dst++ = val;
- }
- /* And then duplicate it across the row */
- for (j = w; j > 0; j--)
- {
- *dst = dst[-n];
- dst++;
- }
- }
- }
- else
- {
- w = (w-1)*n;
- for (i=weights->count; i > 0; i--)
- {
- /* Scale the next pixel in the column */
- min = *contrib++;
- len = *contrib++;
- min *= n;
- for (j = 0; j < n; j++)
- tmp[j] = 0;
- while (len-- > 0)
- {
- for (j = 0; j < n; j++)
- tmp[j] += src[min++] * *contrib;
- contrib++;
- }
- for (j = 0; j < n; j++)
- {
- val = (tmp[j]+(1<<7))>>8;
- if (val < 0)
- val = 0;
- else if (val > 255)
- val = 255;
- *dst++ = val;
- }
- /* And then duplicate it across the row */
- for (j = w; j > 0; j--)
- {
- *dst = dst[-n];
- dst++;
- }
- }
- }
-}
-#endif /* SINGLE_PIXEL_SPECIALS */
-
-fz_pixmap *
-fz_scalepixmap(fz_pixmap *src, float x, float y, float w, float h)
-{
- fz_scalefilter *filter = &fz_scalefilter_simple;
- fz_weights *contrib_rows = NULL;
- fz_weights *contrib_cols = NULL;
- fz_pixmap *output = NULL;
- int *temp = NULL;
- int max_row, temp_span, temp_rows, row;
- int dst_w_int, dst_h_int, dst_x_int, dst_y_int;
- int flip_x, flip_y;
-
- DBUG(("Scale: (%d,%d) to (%g,%g) at (%g,%g)\n",src->w,src->h,w,h,x,y));
-
- /* Find the destination bbox, width/height, and sub pixel offset,
- * allowing for whether we're flipping or not. */
- /* Note that the x and y sub pixel offsets here are different.
- * The (x,y) position given describes where the bottom left corner
- * of the source image should be mapped to (i.e. where (0,h) in image
- * space ends up, not the more logical and sane (0,0)). Also there
- * are differences in the way we scale horizontally and vertically.
- * When scaling rows horizontally, we always read forwards through
- * the source, and store either forwards or in reverse as required.
- * When scaling vertically, we always store out forwards, but may
- * feed source rows in in a different order.
- *
- * Consider the image rectange 'r' to which the image is mapped,
- * and the (possibly) larger rectangle 'R', given by expanding 'r' to
- * complete pixels.
- *
- * x can either be r.xmin-R.xmin or R.xmax-r.xmax depending on whether
- * the image is x flipped or not. Whatever happens 0 <= x < 1.
- * y is always R.ymax - r.ymax.
- */
- /* dst_x_int is calculated to be the left of the scaled image, and
- * x (the sub_pixel_offset) is the distance in from either the left
- * or right pixel expanded edge. */
- flip_x = (w < 0);
- if (flip_x)
- {
- float tmp;
- w = -w;
- dst_x_int = floor(x-w);
- tmp = ceilf(x);
- dst_w_int = (int)tmp;
- x = tmp - x;
- dst_w_int -= dst_x_int;
- }
- else
- {
- dst_x_int = floor(x);
- x -= (float)dst_x_int;
- dst_w_int = (int)ceilf(x + w);
- }
- flip_y = (h < 0);
- /* dst_y_int is calculated to be the bottom of the scaled image, but
- * y (the sub pixel offset) has to end up being the value at the top.
- */
- if (flip_y)
- {
- h = -h;
- dst_y_int = floor(y-h);
- dst_h_int = (int)ceilf(y) - dst_y_int;
- } else {
- dst_y_int = floor(y);
- y += h;
- dst_h_int = (int)ceilf(y) - dst_y_int;
- }
- /* y is the top edge position in floats. We want it to be the
- * distance down from the next pixel boundary. */
- y = ceilf(y) - y;
-
- DBUG(("Result image: (%d,%d) at (%d,%d) (subpix=%g,%g)\n", dst_w_int, dst_h_int, dst_x_int, dst_y_int, x, y));
-
- /* Step 1: Calculate the weights for columns and rows */
-#ifdef SINGLE_PIXEL_SPECIALS
- if (src->w == 1)
- {
- contrib_cols = NULL;
- }
- else
-#endif /* SINGLE_PIXEL_SPECIALS */
- {
- contrib_cols = make_weights(src->w, x, w, filter, 0, dst_w_int, src->n, flip_x);
- if (contrib_cols == NULL)
- goto cleanup;
- }
-#ifdef SINGLE_PIXEL_SPECIALS
- if (src->h == 1)
- {
- contrib_rows = NULL;
- }
- else
-#endif /* SINGLE_PIXEL_SPECIALS */
- {
- contrib_rows = make_weights(src->h, y, h, filter, 1, dst_h_int, src->n, flip_y);
- if (contrib_rows == NULL)
- goto cleanup;
- }
-
- assert(contrib_cols == NULL || contrib_cols->count == dst_w_int);
- assert(contrib_rows == NULL || contrib_rows->count == dst_h_int);
- output = fz_newpixmap(src->colorspace, dst_x_int, dst_y_int, dst_w_int, dst_h_int);
- if (output == NULL)
- goto cleanup;
-
- /* Step 2: Apply the weights */
-#ifdef SINGLE_PIXEL_SPECIALS
- if (contrib_rows == NULL)
- {
- /* Only 1 source pixel high. */
- if (contrib_cols == NULL)
- {
- /* Only 1 pixel in the entire image! */
- duplicate_single_pixel(output->samples, src->samples, src->n, dst_w_int, dst_h_int);
- }
- else
- {
- /* Scale the row once, then copy it. */
- scale_single_row(output->samples, src->samples, contrib_cols, src->w, dst_h_int);
- }
- }
- else if (contrib_cols == NULL)
- {
- /* Only 1 source pixel wide. Scale the col and duplicate. */
- scale_single_col(output->samples, src->samples, contrib_rows, src->h, src->n, dst_w_int, flip_y);
- }
- else
-#endif /* SINGLE_PIXEL_SPECIALS */
- {
- void (*row_scale)(int *dst, unsigned char *src, fz_weights *weights);
-
- temp_span = contrib_cols->count * src->n;
- temp_rows = contrib_rows->max_len;
- if (temp_span <= 0 || temp_rows > INT_MAX / temp_span)
- goto cleanup;
- temp = fz_calloc(temp_span*temp_rows, sizeof(int));
- if (temp == NULL)
- goto cleanup;
- switch (src->n)
- {
- default:
- row_scale = scale_row_to_temp;
- break;
- case 1: /* Image mask case */
- row_scale = scale_row_to_temp1;
- break;
- case 2: /* Greyscale with alpha case */
- row_scale = scale_row_to_temp2;
- break;
- case 4: /* RGBA */
- row_scale = scale_row_to_temp4;
- break;
- }
- max_row = 0;
- for (row = 0; row < contrib_rows->count; row++)
- {
- /*
- Which source rows do we need to have scaled into the
- temporary buffer in order to be able to do the final
- scale?
- */
- int row_index = contrib_rows->index[row];
- int row_min = contrib_rows->index[row_index++];
- int row_len = contrib_rows->index[row_index++];
- while (max_row < row_min+row_len)
- {
- /* Scale another row */
- assert(max_row < src->h);
- DBUG(("scaling row %d to temp\n", max_row));
- (*row_scale)(&temp[temp_span*(max_row % temp_rows)], &src->samples[(flip_y ? (src->h-1-max_row): max_row)*src->w*src->n], contrib_cols);
- max_row++;
- }
-
- DBUG(("scaling row %d from temp\n", row));
- scale_row_from_temp(&output->samples[row*output->w*output->n], temp, contrib_rows, temp_span, row);
- }
- fz_free(temp);
- }
-
-cleanup:
- fz_free(contrib_rows);
- fz_free(contrib_cols);
- return output;
-}