[winpr,rdtk] use png only if supported by winpr

rdtk compiles in bitmaps of fonts. if png format is supported by winpr,
prefer the png images, otherwise use bmp

rdtk/librdtk/rdtk_font.c

@@ -20,6 +20,7 @@
 
 #include <errno.h>
 
+#include <winpr/config.h>
 #include <winpr/wtypes.h>
 #include <winpr/crt.h>
 #include <winpr/assert.h>
@@ -33,6 +34,12 @@
 
 #include "rdtk_font.h"
 
+#if defined(WINPR_WITH_PNG)
+#define FILE_EXT "png"
+#else
+#define FILE_EXT "bmp"
+#endif
+
 static int rdtk_font_draw_glyph(rdtkSurface* surface, int nXDst, int nYDst, rdtkFont* font,
                                 rdtkGlyph* glyph)
 {
@@ -618,7 +625,8 @@ rdtkFont* rdtk_font_new(rdtkEngine* engine, const char* path, const char* file)
 	if (!fontImageFile)
 		goto cleanup;
 
-	sprintf_s(fontImageFile, length + 8, "%s.png", fontBaseFile);
+	sprintf_s(fontImageFile, length + 8, "%s." FILE_EXT, fontBaseFile);
+
 	fontDescriptorFile = (char*)malloc(length + 8);
 
 	if (!fontDescriptorFile)
@@ -750,7 +758,8 @@ int rdtk_font_engine_init(rdtkEngine* engine)
 		SSIZE_T descriptorSize;
 		const uint8_t* imageData = NULL;
 		const uint8_t* descriptorData = NULL;
-		imageSize = rdtk_get_embedded_resource_file("source_serif_pro_regular_12.png", &imageData);
+		imageSize =
+		    rdtk_get_embedded_resource_file("source_serif_pro_regular_12." FILE_EXT, &imageData);
 		descriptorSize =
 		    rdtk_get_embedded_resource_file("source_serif_pro_regular_12.xml", &descriptorData);
 

rdtk/librdtk/rdtk_nine_patch.c

@@ -16,12 +16,20 @@
  * limitations under the License.
  */
 
+#include <winpr/config.h>
+
 #include <rdtk/config.h>
 
 #include "rdtk_resources.h"
 
 #include "rdtk_nine_patch.h"
 
+#if defined(WINPR_WITH_PNG)
+#define FILE_EXT "png"
+#else
+#define FILE_EXT "bmp"
+#endif
+
 static int rdtk_image_copy_alpha_blend(uint8_t* pDstData, int nDstStep, int nXDst, int nYDst,
                                        int nWidth, int nHeight, uint8_t* pSrcData, int nSrcStep,
                                        int nXSrc, int nYSrc)
@@ -373,7 +381,7 @@ int rdtk_nine_patch_engine_init(rdtkEngine* engine)
 		SSIZE_T size;
 		const uint8_t* data;
 		status = -1;
-		size = rdtk_get_embedded_resource_file("btn_default_normal.9.png", &data);
+		size = rdtk_get_embedded_resource_file("btn_default_normal.9." FILE_EXT, &data);
 
 		if (size > 0)
 		{
@@ -401,7 +409,7 @@ int rdtk_nine_patch_engine_init(rdtkEngine* engine)
 		SSIZE_T size;
 		const uint8_t* data;
 		status = -1;
-		size = rdtk_get_embedded_resource_file("textfield_default.9.png", &data);
+		size = rdtk_get_embedded_resource_file("textfield_default.9." FILE_EXT, &data);
 		image = NULL;
 
 		if (size > 0)

rdtk/librdtk/rdtk_surface.c

@@ -71,8 +71,6 @@ rdtkSurface* rdtk_surface_new(rdtkEngine* engine, uint8_t* data, uint16_t width,
 			return NULL;
 		}
 
-		memset(surface->data, 0, surface->scanline * surface->height);
-
 		surface->owner = true;
 	}