1 files changed, 118 insertions, 0 deletions
diff --git a/src/ScanImage.cxx b/src/ScanImage.cxx
new file mode 100644
index 0000000..747da36
--- /dev/null
+++ b/src/ScanImage.cxx
@@ -0,0 +1,118 @@
+//
+// Copyright 2007-2009 Johannes Hofmann <Johannes.Hofmann@gmx.de>
+//
+// This software may be used and distributed according to the terms
+// of the GNU General Public License, incorporated herein by reference.
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+
+#include <Fl/Fl_Image.H>
+#include "ScanImage.H"
+
+int
+ScanImage::get_pixel(Fl_Image *img, mode_t mode,
+	double x, double y, int *r, int *g, int *b) {
+	if (mode == BICUBIC)
+		return get_pixel_bicubic(img, x, y, r, g, b);
+	else
+		return get_pixel_nearest(img, x, y, r, g, b);
+}
+
+int
+ScanImage::get_pixel_nearest(Fl_Image *img, double x, double y,
+    int *r, int *g, int *b) {
+
+    if (isnan(x) || isnan(y))
+        return 1;
+    else
+        return get_pixel(img, (int) rint(x), (int) rint(y), r, g, b);
+}
+
+static inline double
+interp_cubic(double x, double x2, double x3, double *v) {
+    double a0, a1, a2, a3;
+
+    a0 = v[3] - v[2] - v[0] + v[1];
+    a1 = v[0] - v[1] - a0;
+    a2 = v[2] - v[0];
+    a3 = v[1];
+
+    return a0 * x3 + a1 * x2 + a2 * x + a3;
+}
+
+int
+ScanImage::get_pixel_bicubic(Fl_Image *img, double x, double y,
+    int *r, int *g, int *b) {
+
+    double fl_x = floor(x);
+    double fl_y = floor(y);
+    double dx = x - fl_x, dx2 = dx * dx, dx3 = dx2 * dx;
+    double dy = y - fl_y, dy2 = dy * dy, dy3 = dy2 * dy;
+    int ic[3];
+    double c[3][4];
+    double c1[3][4];
+
+    for (int iy = 0; iy < 4; iy++) {
+        for (int ix = 0; ix < 4; ix++) {
+
+            if (get_pixel(img, (int) fl_x + ix - 1, (int) fl_y + iy - 1,
+                    &ic[0], &ic[1], &ic[2]) != 0)
+                return 1;
+
+            for (int l = 0; l < 3; l++)
+                c[l][ix] = (double) ic[l];
+        }
+
+        for (int l = 0; l < 3; l++)
+            c1[l][iy] = interp_cubic(dx, dx2, dx3, c[l]);
+    }
+
+    *r = (int) rint(interp_cubic(dy, dy2, dy3, c1[0]));
+    *g = (int) rint(interp_cubic(dy, dy2, dy3, c1[1]));
+    *b = (int) rint(interp_cubic(dy, dy2, dy3, c1[2]));
+    return 0;
+}
+
+int
+ScanImage::get_pixel(Fl_Image *img, int x, int y,
+                     int *r, int *g, int *b) {
+    if ( img->d() == 0 )
+        return 1;
+
+    if (x < 0 || x >=img->w() || y < 0 || y >= img->h())
+        return 1;
+
+    long index = (y * img->w() * img->d()) + (x * img->d()); // X/Y -> buf index  
+    switch (img->count()) {
+        case 1:
+        {                                            // bitmap
+            const unsigned char *buf = (const unsigned char*) img->data()[0];
+            switch (img->d())
+            {
+                case 1:
+                    *r = *g = *b = *(buf+index);
+                    break;
+                case 3:                              // 24bit
+                    *r = (int) *(buf+index+0);
+                    *g = (int) *(buf+index+1);
+                    *b = (int) *(buf+index+2);
+                    break;
+                default:                             // ??
+                    printf("Not supported: chans=%d\n", img->d());
+                    return 1;
+            }
+            break;
+        }
+        default:                                             // ?? pixmap, bit vals
+        printf("Not supported: count=%d\n", img->count());
+        return 1;
+    }
+
+    *r = *r * 255;
+    *g = *g * 255;
+    *b = *b * 255;
+
+    return 0;
+}