diff options
Diffstat (limited to 'draw/imagesmooth.c')
-rw-r--r-- | draw/imagesmooth.c | 1175 |
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; -} |