Added support for reading and writing TIFFTAG_XRESOLUTION and

TIFFTAG_YRESOLUTION.  Includes a unit test.

2 files changed, 80 insertions, 0 deletions

diff --git a/tests/tiff/CMakeLists.txt b/tests/tiff/CMakeLists.txt
index da49800..aa8b8b2 100644
--- a/tests/tiff/CMakeLists.txt
+++ b/tests/tiff/CMakeLists.txt
@@ -2,6 +2,7 @@
 SET(TESTS_FILES
 	tiff_im2im
 	tiff_null
+	tiff_dpi
 )
 
 FOREACH(test_name ${TESTS_FILES})
diff --git a/tests/tiff/tiff_dpi.c b/tests/tiff/tiff_dpi.c
new file mode 100644
index 0000000..3d4a21a
--- /dev/null
+++ b/tests/tiff/tiff_dpi.c
@@ -0,0 +1,79 @@
+/* 
+ * Test that reading and writing image resolution values to/from TIFF files
+ * works correctly.  Set the image resolution, write the file, read the file
+ * back and test that the image resolution comes back correct.
+ */
+#include "gd.h"
+#include "gdtest.h"
+
+int main()
+{
+	gdImagePtr src, dst;
+	int r, res_x, res_y;
+	void *p;
+	int size = 0;
+	int status = 0;
+
+	src = gdImageCreate(100, 100);
+	if (src == NULL) {
+		printf("could not create src\n");
+		return 1;
+	}
+	r = gdImageColorAllocate(src, 0xFF, 0, 0);
+	gdImageFilledRectangle(src, 0, 0, 99, 99, r);
+
+	// gd default DPI is 96; libtiff default is 72.  
+	// Use something else so we know the value has been
+	// written / read correctly.
+	res_x = 100;
+	res_y = 200;
+	src->res_x = res_x;
+	src->res_y = res_y;
+
+#define OUTPUT_TIFF(name) do {							\
+		FILE *fp;										\
+														\
+		fp = fopen("tiff_dpi_" #name ".tiff", "wb");	\
+		if (fp) {										\
+			gdImageTiff(name, fp);						\
+			fclose(fp);									\
+		}												\
+	} while (0)
+
+	OUTPUT_TIFF(src);
+	p = gdImageTiffPtr(src, &size);
+	if (p == NULL) {
+		status = 1;
+		printf("p is null\n");
+		goto door0;
+	}
+	if (size <= 0) {
+		status = 1;
+		printf("size is non-positive\n");
+		goto door1;
+	}
+
+	dst = gdImageCreateFromTiffPtr(size, p);
+	if (dst == NULL) {
+		status = 1;
+		printf("could not create dst\n");
+		goto door1;
+	}
+
+	if (dst->res_x != res_x) {
+		status = 1;
+		printf("mismatch in res_x (got %d, expected %d)", dst->res_x, res_x);
+	}
+
+	if (dst->res_y != res_y) {
+		status = 1;
+		printf("mismatch in res_y (got %d, expected %d)", dst->res_y, res_y);
+	}
+
+	gdImageDestroy(dst);
+door1:
+	gdFree(p);
+door0:
+	gdImageDestroy(src);
+	return status;
+}