using png images in tex_unit test

tests/regression/tex/utils.h

@@ -1,7 +1,7 @@
 #include <cstdint>
 #include <vector>
 #include <iostream>
-#include "blitter.h"
+#include "surfacedesc.h"
 
 #define ISPOW2(x)   (((x) != 0) && (0 == ((x) & ((x) - 1))))
 
@@ -9,16 +9,17 @@ inline uint32_t ilog2 (uint32_t value) {
   	return (uint32_t)(sizeof(uint32_t) * 8UL) - (uint32_t)__builtin_clzl((value << 1) - 1UL) - 1;
 }
 
-int LoadTGA(const char *filename, 
-            std::vector<uint8_t> &pixels, 
-            uint32_t *width,
-            uint32_t *height);
+int LoadImage(const char *filename,
+              ePixelFormat format,
+              std::vector<uint8_t> &pixels,
+              uint32_t *width,
+              uint32_t *height);
 
-int SaveTGA(const char *filename, 
-            const std::vector<uint8_t> &pixels, 
-            uint32_t width,
-            uint32_t height, 
-            uint32_t bpp);
+int SaveImage(const char *filename,
+              ePixelFormat format,
+              const std::vector<uint8_t> &pixels,
+              uint32_t width,
+              uint32_t height);
 
 int CopyBuffers(SurfaceDesc &dstDesc, 
                 int32_t dstOffsetX,