Substitute TkPhotoPutBlock

richardsheridan · richardsheridan · commit 8f4ed5d9cb59 · 2021-08-15T08:50:29.000-04:00
Also release GIL

Currently, drawing an equivalence between blank and TK_PHOTO_COMPOSITE_SET which may not be entirely accurate
diff --git a/lib/matplotlib/backends/_backend_tk.py b/lib/matplotlib/backends/_backend_tk.py
@@ -60,15 +60,10 @@ def _blit(argsid):
 
     *argsid* is a unique string identifier to fetch the correct arguments from
     the ``_blit_args`` dict, since arguments cannot be passed directly.
-
-    photoimage blanking must occur in the same event and thread as blitting
-    to avoid flickering.
     """
     photoimage, dataptr, offsets, bboxptr, blank = _blit_args.pop(argsid)
-    if blank:
-        photoimage.blank()
     _tkagg.blit(
-        photoimage.tk.interpaddr(), str(photoimage), dataptr, offsets, bboxptr)
+        photoimage.tk.interpaddr(), str(photoimage), dataptr, blank, offsets, bboxptr)
 
 
 def blit(photoimage, aggimage, offsets, bbox=None):
diff --git a/src/_tkagg.cpp b/src/_tkagg.cpp
@@ -64,13 +64,15 @@ static PyObject *mpl_tk_blit(PyObject *self, PyObject *args)
     char const *photo_name;
     int height, width;
     unsigned char *data_ptr;
+    int blank;
     int o0, o1, o2, o3;
     int x1, x2, y1, y2;
     Tk_PhotoHandle photo;
     Tk_PhotoImageBlock block;
-    if (!PyArg_ParseTuple(args, "O&s(iiO&)(iiii)(iiii):blit",
+    if (!PyArg_ParseTuple(args, "O&s(iiO&)i(iiii)(iiii):blit",
                           convert_voidptr, &interp, &photo_name,
                           &height, &width, convert_voidptr, &data_ptr,
+                          &blank,
                           &o0, &o1, &o2, &o3,
                           &x1, &x2, &y1, &y2)) {
         goto exit;
@@ -83,7 +85,12 @@ static PyObject *mpl_tk_blit(PyObject *self, PyObject *args)
         PyErr_SetString(PyExc_ValueError, "Attempting to draw out of bounds");
         goto exit;
     }
+    if (blank != TK_PHOTO_COMPOSITE_OVERLAY && blank != TK_PHOTO_COMPOSITE_SET){
+        PyErr_SetString(PyExc_ValueError, "Invalid blank argument");
+        goto exit;
+    }
 
+    Py_BEGIN_ALLOW_THREADS
     block.pixelPtr = data_ptr + 4 * ((height - y2) * width + x1);
     block.width = x2 - x1;
     block.height = y2 - y1;
@@ -93,8 +100,10 @@ static PyObject *mpl_tk_blit(PyObject *self, PyObject *args)
     block.offset[1] = o1;
     block.offset[2] = o2;
     block.offset[3] = o3;
-    TK_PHOTO_PUT_BLOCK_NO_COMPOSITE(
-        photo, &block, x1, height - y2, x2 - x1, y2 - y1);
+    TK_PHOTO_PUT_BLOCK(
+        interp, photo, &block, x1, height - y2, x2 - x1, y2 - y1, blank);
+    Py_END_ALLOW_THREADS
+
 exit:
     if (PyErr_Occurred()) {
         return NULL;
diff --git a/src/_tkmini.h b/src/_tkmini.h
@@ -86,8 +86,8 @@ typedef struct Tk_PhotoImageBlock
     int offset[4];
 } Tk_PhotoImageBlock;
 
-#define TK_PHOTO_COMPOSITE_OVERLAY	0
-#define TK_PHOTO_COMPOSITE_SET		1
+#define TK_PHOTO_COMPOSITE_OVERLAY	0  // don't blank
+#define TK_PHOTO_COMPOSITE_SET		1  // blank
 
 /* Typedefs derived from function signatures in Tk header */
 /* Tk_FindPhoto typedef */
@@ -96,7 +96,7 @@ typedef Tk_PhotoHandle (*Tk_FindPhoto_t) (Tcl_Interp *interp, const char
 /* Tk_PhotoPutBLock typedef */
 typedef int (*Tk_PhotoPutBlock_t) (Tcl_Interp *interp, Tk_PhotoHandle handle,
         Tk_PhotoImageBlock *blockPtr, int x, int y,
-        int width, int height);
+        int width, int height, int compRule);
 /* Tk_PhotoPutBLock_NoComposite typedef */
 typedef void (*Tk_PhotoPutBlock_NoComposite_t) (Tk_PhotoHandle handle,
         Tk_PhotoImageBlock *blockPtr, int x, int y,
