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index 3b8461383d4eacf1ff4957e3ca2e59b44028175a..39c82daf6ed9ba5808f70514afd1b85b4c6efacc 100644 (file)
#define __NR_PIXBLOCK_SCALER_CPP__
+/*
+ * Functions for blitting pixblocks using scaling
+ *
+ * Author:
+ * Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2006 Niko Kiirala
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
#include <glib.h>
#include <cmath>
using std::floor;
+#include "display/nr-filter-utils.h"
#include "libnr/nr-pixblock.h"
+#include "libnr/nr-blit.h"
namespace NR {
int r, g, b, a;
};
-inline int sampley(unsigned const char a, unsigned const char b, unsigned const char c, unsigned const char d, const double len) {
+/** Calculates cubically interpolated value of the four given pixel values.
+ * The pixel values should be from four vertically adjacent pixels.
+ * If we are calculating a pixel, whose y-coordinate in source image is
+ * i, these pixel values a, b, c and d should come from lines
+ * floor(i) - 1, floor(i), floor(i) + 1, floor(i) + 2, respectively.
+ * Parameter len should be set to i.
+ * Returns the interpolated value in fixed point format with 8 bit
+ * decimal part. (24.8 assuming 32-bit int)
+ */
+__attribute__ ((const))
+inline static int sampley(unsigned const char a, unsigned const char b,
+ unsigned const char c, unsigned const char d,
+ const double len)
+{
double lenf = len - floor(len);
int sum = 0;
sum += (int)((((-1.0 / 3.0) * lenf + 4.0 / 5.0) * lenf - 7.0 / 15.0)
return sum;
}
-inline unsigned char samplex(const int a, const int b, const int c, const int d, const double len) {
+/** Calculates cubically interpolated value of the four given pixel values.
+ * The pixel values should be interpolated values from sampley, from four
+ * horizontally adjacent vertical lines. The parameters a, b, c and d
+ * should be in fixed point format with 8-bit decimal part.
+ * If we are calculating a pixel, whose x-coordinate in source image is
+ * i, these vertical lines from where a, b, c and d are calculated, should be
+ * floor(i) - 1, floor(i), floor(i) + 1, floor(i) + 2, respectively.
+ * Parameter len should be set to i.
+ * Returns the interpolated value in 8-bit format, ready to be written
+ * to output buffer.
+ */
+inline static int samplex(const int a, const int b, const int c, const int d, const double len) {
double lenf = len - floor(len);
int sum = 0;
sum += (int)(a * (((-1.0 / 3.0) * lenf + 4.0 / 5.0) * lenf - 7.0 / 15.0) * lenf);
sum += (int)(b * (((lenf - 9.0 / 5.0) * lenf - 1.0 / 5.0) * lenf + 1.0));
sum += (int)(c * ((((1 - lenf) - 9.0 / 5.0) * (1 - lenf) - 1.0 / 5.0) * (1 - lenf) + 1.0));
sum += (int)(d * (((-1.0 / 3.0) * (1 - lenf) + 4.0 / 5.0) * (1 - lenf) - 7.0 / 15.0) * (1 - lenf));
- if (sum < 0) sum = 0;
- if (sum > 255*256) sum = 255 * 256;
- return (unsigned char)(sum / 256);
+ //if (sum < 0) sum = 0;
+ //if (sum > 255 * 256) sum = 255 * 256;
+ return sum / 256;
}
/**
@@ -43,27 +80,47 @@ inline unsigned char samplex(const int a, const int b, const int c, const int d,
* Catches reading and writing outside the pixblock area.
* When enabled, decreases filter rendering speed massively.
*/
-inline void _check_index(NRPixBlock const * const pb, int const location, int const line)
+inline static void _check_index(NRPixBlock const * const pb, int const location, int const line)
{
- if(true) {
+ if(false) {
int max_loc = pb->rs * (pb->area.y1 - pb->area.y0);
- if (location < 0 || (location + 4) >= max_loc)
+ if (location < 0 || (location + 4) > max_loc)
g_warning("Location %d out of bounds (0 ... %d) at line %d", location, max_loc, line);
}
}
-void scale_bicubic(NRPixBlock *to, NRPixBlock *from)
+static void scale_bicubic_rgba(NRPixBlock *to, NRPixBlock *from)
{
+ if (NR_PIXBLOCK_BPP(from) != 4 || NR_PIXBLOCK_BPP(to) != 4) {
+ g_warning("A non-32-bpp image passed to scale_bicubic_rgba: scaling aborted.");
+ return;
+ }
+
+ bool free_from_on_exit = false;
+ if (from->mode != to->mode){
+ NRPixBlock *o_from = from;
+ from = new NRPixBlock;
+ nr_pixblock_setup_fast(from, to->mode, o_from->area.x0, o_from->area.y0, o_from->area.x1, o_from->area.y1, false);
+ nr_blit_pixblock_pixblock(from, o_from);
+ free_from_on_exit = true;
+ }
+
+ // Precalculate sizes of source and destination pixblocks
int from_width = from->area.x1 - from->area.x0;
int from_height = from->area.y1 - from->area.y0;
int to_width = to->area.x1 - to->area.x0;
int to_height = to->area.y1 - to->area.y0;
+ // from_step: when advancing one pixel in destination image,
+ // how much we should advance in source image
double from_stepx = (double)from_width / (double)to_width;
double from_stepy = (double)from_height / (double)to_height;
+ // Loop through every pixel of destination image, a line at a time
for (int to_y = 0 ; to_y < to_height ; to_y++) {
double from_y = to_y * from_stepy + from_stepy / 2;
+ // Pre-calculate beginning of the four horizontal lines, from
+ // which we should read
int from_line[4];
for (int i = 0 ; i < 4 ; i++) {
if ((int)floor(from_y) + i - 1 >= 0) {
from_line[i] = 0;
}
}
+ // Loop through this horizontal line in destination image
+ // For every pixel, calculate the color of pixel with
+ // bicubic interpolation and set the pixel value in destination image
for (int to_x = 0 ; to_x < to_width ; to_x++) {
double from_x = to_x * from_stepx + from_stepx / 2;
RGBA line[4];
from_x);
_check_index(to, to_y * to->rs + to_x * 4, __LINE__);
- NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4] = result.r;
- NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 1] = result.g;
- NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 2] = result.b;
- NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 3] = result.a;
+
+ if (to->mode == NR_PIXBLOCK_MODE_R8G8B8A8P) {
+ /* Clamp the colour channels to range from 0 to result.a to
+ * make sure, we don't exceed 100% per colour channel with
+ * images that have premultiplied alpha */
+
+ result.a = clamp(result.a);
+
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4] = clamp_alpha(result.r, result.a);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 1] = clamp_alpha(result.g, result.a);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 2] = clamp_alpha(result.b, result.a);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 3] = result.a;
+ } else {
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4] = clamp(result.r);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 1] = clamp(result.g);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 2] = clamp(result.b);
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x * 4 + 3] = clamp(result.a);
+ }
}
}
+ if (free_from_on_exit) {
+ nr_pixblock_release(from);
+ delete from;
+ }
+
+}
+
+void scale_bicubic_alpha(NRPixBlock *to, NRPixBlock *from)
+{
+ if (NR_PIXBLOCK_BPP(from) != 1 || NR_PIXBLOCK_BPP(to) != 1) {
+ g_warning("A non-8-bpp image passed to scale_bicubic_alpha: scaling aborted.");
+ return;
+ }
+
+ // Precalculate sizes of source and destination pixblocks
+ int from_width = from->area.x1 - from->area.x0;
+ int from_height = from->area.y1 - from->area.y0;
+ int to_width = to->area.x1 - to->area.x0;
+ int to_height = to->area.y1 - to->area.y0;
+
+ // from_step: when advancing one pixel in destination image,
+ // how much we should advance in source image
+ double from_stepx = (double)from_width / (double)to_width;
+ double from_stepy = (double)from_height / (double)to_height;
+
+ // Loop through every pixel of destination image, a line at a time
+ for (int to_y = 0 ; to_y < to_height ; to_y++) {
+ double from_y = to_y * from_stepy + from_stepy / 2;
+ // Pre-calculate beginning of the four horizontal lines, from
+ // which we should read
+ int from_line[4];
+ for (int i = 0 ; i < 4 ; i++) {
+ if ((int)floor(from_y) + i - 1 >= 0) {
+ if ((int)floor(from_y) + i - 1 < from_height) {
+ from_line[i] = ((int)floor(from_y) + i - 1) * from->rs;
+ } else {
+ from_line[i] = (from_height - 1) * from->rs;
+ }
+ } else {
+ from_line[i] = 0;
+ }
+ }
+ // Loop through this horizontal line in destination image
+ // For every pixel, calculate the color of pixel with
+ // bicubic interpolation and set the pixel value in destination image
+ for (int to_x = 0 ; to_x < to_width ; to_x++) {
+ double from_x = to_x * from_stepx + from_stepx / 2;
+ int line[4];
+ for (int i = 0 ; i < 4 ; i++) {
+ int k = (int)floor(from_x) + i - 1;
+ if (k < 0) k = 0;
+ if (k >= from_width) k = from_width - 1;
+ _check_index(from, from_line[0] + k, __LINE__);
+ _check_index(from, from_line[1] + k, __LINE__);
+ _check_index(from, from_line[2] + k, __LINE__);
+ _check_index(from, from_line[3] + k, __LINE__);
+ line[i] = sampley(NR_PIXBLOCK_PX(from)[from_line[0] + k],
+ NR_PIXBLOCK_PX(from)[from_line[1] + k],
+ NR_PIXBLOCK_PX(from)[from_line[2] + k],
+ NR_PIXBLOCK_PX(from)[from_line[3] + k],
+ from_y);
+ }
+ int result;
+ result = samplex(line[0], line[1], line[2], line[3],
+ from_x);
+
+ _check_index(to, to_y * to->rs + to_x, __LINE__);
+
+ NR_PIXBLOCK_PX(to)[to_y * to->rs + to_x] = clamp(result);
+ }
+ }
+}
+
+void scale_bicubic(NRPixBlock *to, NRPixBlock *from)
+{
+ if (NR_PIXBLOCK_BPP(to) == 4 && NR_PIXBLOCK_BPP(from) == 4) {
+ scale_bicubic_rgba(to, from);
+ } else if (NR_PIXBLOCK_BPP(to) == 1 && NR_PIXBLOCK_BPP(from) == 1) {
+ scale_bicubic_alpha(to, from);
+ } else {
+ g_warning("NR::scale_bicubic: unsupported bitdepths for scaling: to %d, from %d", NR_PIXBLOCK_BPP(to), NR_PIXBLOCK_BPP(from));
+ }
}
} /* namespace NR */