- image->Destroy();
-
- file = fopen(name, "r");
- if (!file)
- return NULL;
-
- done = 0;
- /*
- * Reading the bmp header
- */
-
- fread(&bbuf, 1, 2, file);
-
- fread(dbuf, 4, 4, file);
-
- size = dbuf[0];
- offset = dbuf[2];
-
- fread(dbuf, 4, 2, file);
- int width = (int)dbuf[0];
- int height = (int)dbuf[1];
- if (width > 32767)
- {
- fprintf(stderr, "IMLIB ERROR: Image width > 32767 pixels for file\n");
- fclose(file);
- return FALSE;
- }
- if (height > 32767)
- {
- fprintf(stderr, "IMLIB ERROR: Image height > 32767 pixels for file\n");
- fclose(file);
- return FALSE;
- }
- fread(&word, 2, 1, file);
- planes = (int)word;
- fread(&word, 2, 1, file);
- bpp = (int)word;
- if (bpp != 1 && bpp != 4 && bpp != 8 && bpp && 16 && bpp != 24 && bpp != 32)
- {
- fprintf(stderr, "IMLIB ERROR: unknown bitdepth in file\n");
- fclose(file);
- return FALSE;
- }
- fread(dbuf, 4, 4, file);
- comp = (int)dbuf[0];
- if (comp != BI_RGB && comp != BI_RLE4 && comp != BI_RLE8 && comp != BI_BITFIELDS)
- {
- fprintf(stderr, "IMLIB ERROR: unknown encoding in Windows BMP file\n");
- fclose(file);
- return FALSE;
- }
- fread(dbuf, 4, 2, file);
- ncolors = (int)dbuf[0];
- if (ncolors == 0)
- ncolors = 1 << bpp;
- /* some more sanity checks */
- if (((comp == BI_RLE4) && (bpp != 4)) || ((comp == BI_RLE8) && (bpp != 8)) || ((comp == BI_BITFIELDS) && (bpp != 16 && bpp != 32)))
- {
- fprintf(stderr, "IMLIB ERROR: encoding of BMP doesn't match bitdepth\n");
- fclose(file);
- return FALSE;
- }
- if (bpp < 16)
- {
- cmap = (struct _cmap *)malloc(sizeof(struct _cmap) * ncolors);
-
- if (!cmap)
- {
- fprintf(stderr, "IMLIB ERROR: Cannot allocate RAM for color map in BMP file\n");
- fclose(file);
- return FALSE;
- }
- }
- else
- cmap = NULL;
-
- image->Create( width, height );
- ptr = image->GetData();
- if (!ptr)
- {
- fprintf(stderr, "IMLIB ERROR: Cannot allocate RAM for RGB data in file\n");
- fclose(file);
- if (cmap)
- free(cmap);
- return FALSE;
- }
-
- /*
- * Reading the palette, if it exists.
- */
- if (bpp < 16 && ncolors != 0)
- {
- for (i = 0; i < ncolors; i++)
- {
- fread(bbuf, 1, 4, file);
- cmap[i].b = bbuf[0];
- cmap[i].g = bbuf[1];
- cmap[i].r = bbuf[2];
- }
- }
- else if (bpp == 16 || bpp == 32)
- {
- if (comp == BI_BITFIELDS)
- {
- int bit = 0;
-
- fread(dbuf, 4, 3, file);
- bmask = dbuf[0];
- gmask = dbuf[1];
- rmask = dbuf[2];
- /* find shift amount.. ugly, but i can't think of a better way */
- for (bit = 0; bit < bpp; bit++)
- {
- if (bmask & (1 << bit))
- bshift = bit;
- if (gmask & (1 << bit))
- gshift = bit;
- if (rmask & (1 << bit))
- rshift = bit;
- }
- }
- else if (bpp == 16)
- {
- rmask = 0x7C00;
- gmask = 0x03E0;
- bmask = 0x001F;
- rshift = 10;
- gshift = 5;
- bshift = 0;
- }
- else if (bpp == 32)
- {
- rmask = 0x00FF0000;
- gmask = 0x0000FF00;
- bmask = 0x000000FF;
- rshift = 16;
- gshift = 8;
- bshift = 0;
- }
- }
-
- /*
- * REading the image data
- */
- fseek(file, offset, SEEK_SET);
- data = ptr;
-
- /* set the whole image to the background color */
- if (bpp < 16 && (comp == BI_RLE4 || comp == BI_RLE8))
- {
- for (i = 0; i < width * height; i++)
- {
- *ptr++ = cmap[0].r;
- *ptr++ = cmap[0].g;
- *ptr++ = cmap[0].b;
- }
- ptr = data;
- }
- line = 0;
- column = 0;
-#define poffset (line * width * 3 + column * 3)
-
- /*
- * BMPs are stored upside down... hmmmmmmmmmm....
- */
-
- linesize = ((width * bpp + 31) / 32) * 4;
- for (line = (height - 1); line >= 0; line--)
- {
- linepos = 0;
- for (column = 0; column < width;)
- {
- if (bpp < 16)
- {
- int index;
-
- linepos++;
- byte = getc(file);
- if (bpp == 1)
- {
- int bit = 0;
-
- for (bit = 0; bit < 8; bit++)
- {
- index = ((byte & (0x80 >> bit)) ? 1 : 0);
- ptr[poffset] = cmap[index].r;
- ptr[poffset + 1] = cmap[index].g;
- ptr[poffset + 2] = cmap[index].b;
- column++;
- }
- }
- else if (bpp == 4)
- {
- if (comp == BI_RLE4)
- {
- fprintf(stderr, "can't deal with 4bit encoded yet.\n");
- image->Destroy();
- free(cmap);
- return FALSE;
- }
- else
- {
- int nibble = 0;
-
- for (nibble = 0; nibble < 2; nibble++)
- {
- index = ((byte & (0xF0 >> nibble * 4)) >> (!nibble * 4));
- if (index >= 16)
- index = 15;
- ptr[poffset] = cmap[index].r;
- ptr[poffset + 1] = cmap[index].g;
- ptr[poffset + 2] = cmap[index].b;
- column++;
- }
- }
- }
- else if (bpp == 8)
- {
- if (comp == BI_RLE8)
- {
- unsigned char first;
-
- first = byte;
- byte = getc(file);
- if (first == 0)
- {
- if (byte == 0)
- {
-/* column = width; */
- }
- else if (byte == 1)
- {
- column = width;
- line = -1;
- }
- else if (byte == 2)
- {
- byte = getc(file);
- column += byte;
- linepos = column * bpp / 8;
- byte = getc(file);
- line += byte;
- }
- else
- {
- int absolute = byte;
-
- for (i = 0; i < absolute; i++)
- {
- linepos++;
- byte = getc(file);
- ptr[poffset] = cmap[byte].r;
- ptr[poffset + 1] = cmap[byte].g;
- ptr[poffset + 2] = cmap[byte].b;
- column++;
- }
- if (absolute & 0x01)
- byte = getc(file);
- }
- }
- else
- {
- for (i = 0; i < first; i++)
- {
- ptr[poffset] = cmap[byte].r;
- ptr[poffset + 1] = cmap[byte].g;
- ptr[poffset + 2] = cmap[byte].b;
- column++;
- linepos++;
- }
- }
- }
- else
- {
- ptr[poffset] = cmap[byte].r;
- ptr[poffset + 1] = cmap[byte].g;
- ptr[poffset + 2] = cmap[byte].b;
- column++;
- linepos += size;
- }
- }
- }
- else if (bpp == 24)
- {
- linepos += fread(&bbuf, 1, 3, file);
- ptr[poffset] = (unsigned char)bbuf[2];
- ptr[poffset + 1] = (unsigned char)bbuf[1];
- ptr[poffset + 2] = (unsigned char)bbuf[0];
- column++;
- }
- else if (bpp == 16)
- {
- unsigned char temp;
-
- linepos += fread(&word, 2, 1, file);
- temp = (word & rmask) >> rshift;
- ptr[poffset] = temp;
- temp = (word & gmask) >> gshift;
- ptr[poffset + 1] = temp;
- temp = (word & bmask) >> gshift;
- ptr[poffset + 2] = temp;
- column++;
- }
- else
- {
- unsigned char temp;
-
- linepos += fread(&dword, 4, 1, file);
- temp = (dword & rmask) >> rshift;
- ptr[poffset] = temp;
- temp = (dword & gmask) >> gshift;
- ptr[poffset + 1] = temp;
- temp = (dword & bmask) >> bshift;
- ptr[poffset + 2] = temp;
- column++;
- }
- }
- while ((linepos < linesize) && (comp != 1) && (comp != 2))
- {
- int temp = fread(&byte, 1, 1, file);
-
- linepos += temp;
- if (!temp)
- break;
- }
- }
- if (cmap) free(cmap);
-
- image->SetMask( FALSE );
-
- fclose(file);
- return TRUE;
+ int x;
+ if (interpolating)
+ {
+ for (int y = 0; y < rotated.GetHeight(); y++)
+ {
+ for (x = 0; x < rotated.GetWidth(); x++)
+ {
+ wxRealPoint src = rotated_point (x + x1, y + y1, cos_angle, -sin_angle, p0);
+
+ if (-0.25 < src.x && src.x < GetWidth() - 0.75 &&
+ -0.25 < src.y && src.y < GetHeight() - 0.75)
+ {
+ // interpolate using the 4 enclosing grid-points. Those
+ // points can be obtained using floor and ceiling of the
+ // exact coordinates of the point
+ // C.M. 2000-02-17: when the point is near the border, special care is required.
+
+ int x1, y1, x2, y2;
+
+ if (0 < src.x && src.x < GetWidth() - 1)
+ {
+ x1 = wxCint(floor(src.x));
+ x2 = wxCint(ceil(src.x));
+ }
+ else // else means that x is near one of the borders (0 or width-1)
+ {
+ x1 = x2 = wxCint (src.x);
+ }
+
+ if (0 < src.y && src.y < GetHeight() - 1)
+ {
+ y1 = wxCint(floor(src.y));
+ y2 = wxCint(ceil(src.y));
+ }
+ else
+ {
+ y1 = y2 = wxCint (src.y);
+ }
+
+ // get four points and the distances (square of the distance,
+ // for efficiency reasons) for the interpolation formula
+
+ // GRG: Do not calculate the points until they are
+ // really needed -- this way we can calculate
+ // just one, instead of four, if d1, d2, d3
+ // or d4 are < gs_Epsilon
+
+ const double d1 = (src.x - x1) * (src.x - x1) + (src.y - y1) * (src.y - y1);
+ const double d2 = (src.x - x2) * (src.x - x2) + (src.y - y1) * (src.y - y1);
+ const double d3 = (src.x - x2) * (src.x - x2) + (src.y - y2) * (src.y - y2);
+ const double d4 = (src.x - x1) * (src.x - x1) + (src.y - y2) * (src.y - y2);
+
+ // Now interpolate as a weighted average of the four surrounding
+ // points, where the weights are the distances to each of those points
+
+ // If the point is exactly at one point of the grid of the source
+ // image, then don't interpolate -- just assign the pixel
+
+ if (d1 < gs_Epsilon) // d1,d2,d3,d4 are positive -- no need for abs()
+ {
+ unsigned char *p = data[y1] + (3 * x1);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ }
+ else if (d2 < gs_Epsilon)
+ {
+ unsigned char *p = data[y1] + (3 * x2);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ }
+ else if (d3 < gs_Epsilon)
+ {
+ unsigned char *p = data[y2] + (3 * x2);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ }
+ else if (d4 < gs_Epsilon)
+ {
+ unsigned char *p = data[y2] + (3 * x1);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ }
+ else
+ {
+ // weights for the weighted average are proportional to the inverse of the distance
+ unsigned char *v1 = data[y1] + (3 * x1);
+ unsigned char *v2 = data[y1] + (3 * x2);
+ unsigned char *v3 = data[y2] + (3 * x2);
+ unsigned char *v4 = data[y2] + (3 * x1);
+
+ const double w1 = 1/d1, w2 = 1/d2, w3 = 1/d3, w4 = 1/d4;
+
+ // GRG: Unrolled.
+
+ *(dst++) = (unsigned char)
+ ( (w1 * *(v1++) + w2 * *(v2++) +
+ w3 * *(v3++) + w4 * *(v4++)) /
+ (w1 + w2 + w3 + w4) );
+ *(dst++) = (unsigned char)
+ ( (w1 * *(v1++) + w2 * *(v2++) +
+ w3 * *(v3++) + w4 * *(v4++)) /
+ (w1 + w2 + w3 + w4) );
+ *(dst++) = (unsigned char)
+ ( (w1 * *(v1++) + w2 * *(v2++) +
+ w3 * *(v3++) + w4 * *(v4++)) /
+ (w1 + w2 + w3 + w4) );
+ }
+ }
+ else
+ {
+ *(dst++) = blank_r;
+ *(dst++) = blank_g;
+ *(dst++) = blank_b;
+ }
+ }
+ }
+ }
+ else // not interpolating
+ {
+ for (int y = 0; y < rotated.GetHeight(); y++)
+ {
+ for (x = 0; x < rotated.GetWidth(); x++)
+ {
+ wxRealPoint src = rotated_point (x + x1, y + y1, cos_angle, -sin_angle, p0);
+
+ const int xs = wxCint (src.x); // wxCint rounds to the
+ const int ys = wxCint (src.y); // closest integer
+
+ if (0 <= xs && xs < GetWidth() &&
+ 0 <= ys && ys < GetHeight())
+ {
+ unsigned char *p = data[ys] + (3 * xs);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ *(dst++) = *(p++);
+ }
+ else
+ {
+ *(dst++) = blank_r;
+ *(dst++) = blank_g;
+ *(dst++) = blank_b;
+ }
+ }
+ }
+ }
+
+ delete [] data;
+
+ return rotated;