sw_engine raster: allow image interpolation by increasing tolerance.

current image interpolation method is a bit awkward,
because xy scale different scale factor is not allowed.

we must improve the algorithm,

but now considering floating point precision,
we allow the interpolation by less ratio floating fraction.

diff --git a/src/lib/sw_engine/tvgSwRaster.cpp b/src/lib/sw_engine/tvgSwRaster.cpp
index be24b47..b7f6a4c 100644 (file)
--- a/src/lib/sw_engine/tvgSwRaster.cpp
+++ b/src/lib/sw_engine/tvgSwRaster.cpp
@@ -1555,12 +1555,9 @@ bool rasterImage(SwSurface* surface, SwImage* image, const Matrix* transform, co
         scale = sqrtf((transform->e11 * transform->e11) + (transform->e21 * transform->e21));
         auto scaleY = sqrtf((transform->e22 * transform->e22) + (transform->e12 * transform->e12));
         //TODO:If the x and y axis scale is different, a separate interpolation algorithm for each axis should be applied.
-        if (fabsf(scale - scaleY) > FLT_EPSILON) scale = 1.0f;
+        if (fabsf(scale - scaleY) > 0.01f) scale = 1.0f;
         if (!mathIdentity(transform)) transformed = true;
-    //TODO: Figure out the scale factor by the image size & drawing region
-    } else {
-        mathIdentity(&itransform);
-    }
+    } else mathIdentity(&itransform);
 
     auto translucent = _translucent(surface, opacity);
     auto downScaleTolerance = 0.5f;