Revision: 75599
http://sourceforge.net/p/brlcad/code/75599
Author: starseeker
Date: 2020-04-24 21:00:13 +0000 (Fri, 24 Apr 2020)
Log Message:
-----------
Checkpoint an experiment with Tk_PhotoImage - after studying the C api and some
discussions with the tcl IRC channel, it should be possible to leverage
Tk_Photo for image data display from C. This program generates patterns of
data in an image and uses Tk_PhotoPutBlock to both update the image data itself
and let Tk know it needs to redraw. In theory this should be no different than
getting RGBA values from a rasterizer or raytracer. Not doing any event
handling yet, however.
Modified Paths:
--------------
brlcad/trunk/src/libdm/CMakeLists.txt
Added Paths:
-----------
brlcad/trunk/src/libdm/tcl_img.cpp
Modified: brlcad/trunk/src/libdm/CMakeLists.txt
===================================================================
--- brlcad/trunk/src/libdm/CMakeLists.txt 2020-04-23 23:35:43 UTC (rev
75598)
+++ brlcad/trunk/src/libdm/CMakeLists.txt 2020-04-24 21:00:13 UTC (rev
75599)
@@ -129,6 +129,10 @@
if(BRLCAD_ENABLE_OSG)
add_dependencies(libdm profont_ProFont_ttf_cp)
endif(BRLCAD_ENABLE_OSG)
+
+#add_executable(tcl_img tcl_img.cpp)
+#target_link_libraries(tcl_img ${TCL_LIBRARY} ${TK_LIBRARY})
+
set(libdm_ignore_files
CMakeLists.txt
README
@@ -157,6 +161,7 @@
fontstash/stb_truetype.h
osg-test.cpp
osg_bob.cpp
+ tcl_img.cpp
)
CMAKEFILES(${libdm_ignore_files})
CMAKEFILES(dm_private.h)
Added: brlcad/trunk/src/libdm/tcl_img.cpp
===================================================================
--- brlcad/trunk/src/libdm/tcl_img.cpp (rev 0)
+++ brlcad/trunk/src/libdm/tcl_img.cpp 2020-04-24 21:00:13 UTC (rev 75599)
@@ -0,0 +1,149 @@
+/* T C L _ I M G . C P P
+ * BRL-CAD
+ *
+ * Published in 2020 by the United States Government.
+ * This work is in the public domain.
+ *
+ */
+/** @file tcl_img.cpp
+ *
+ * Self contained example of working with image data
+ * in Tcl/Tk in C/C++
+ *
+ * Eventually this should probably turn into a Togl-esque
+ * widget that we properly include, so we ensure that our
+ * window is behaving the way Tk expects it to for things
+ * like refresh. Our current behavior in that regard is
+ * a bit iffy - ogl works but I'm not convinced that's
+ * because we're doing the Tcl/Tk bits right, and X is
+ * doing low level blitting and other X calls (which
+ * isn't great for maintainability/portability and
+ * can be a headache for debugging.)
+ *
+ */
+
+#include "common.h"
+
+#include <random>
+#include <vector>
+#include <iostream>
+#include <chrono>
+#include <thread>
+
+#include "tcl.h"
+#include "tk.h"
+
+const char *DM_PHOTO = ".dm0.photo";
+const char *DM_LABEL = ".dm0";
+
+void
+update_data(Tcl_Interp *interp, int r, int g, int b)
+{
+ Tk_PhotoImageBlock dm_data;
+ Tk_PhotoHandle dm_img = Tk_FindPhoto(interp, DM_PHOTO);
+ Tk_PhotoGetImage(dm_img, &dm_data);
+
+ std::default_random_engine gen;
+ std::uniform_int_distribution<int> vals(0,255);
+ for (int i = 0; i < (dm_data.width * dm_data.height * 4); i+=4) {
+ dm_data.pixelPtr[i] = (r) ? vals(gen) : 0;
+ dm_data.pixelPtr[i+1] = (g) ? vals(gen) : 0;
+ dm_data.pixelPtr[i+2] = (b) ? vals(gen) : 0;
+ // Alpha stays at 255
+ }
+
+ Tk_PhotoPutBlock(interp, dm_img, &dm_data, 0, 0, dm_data.width,
dm_data.height, TK_PHOTO_COMPOSITE_SET);
+
+ // Pause a second after updating
+ std::this_thread::sleep_for (std::chrono::seconds(1));
+}
+
+
+int
+main()
+{
+ std::default_random_engine gen;
+ std::uniform_int_distribution<int> vals(0,255);
+ std::vector<int> rgb;
+ int wsize = 512;
+
+ for (int i = 0; i < wsize; i++) {
+ for (int j = 0; j < wsize; j++) {
+ rgb.push_back(0);
+ rgb.push_back(vals(gen));
+ rgb.push_back(0);
+ rgb.push_back(255);
+ }
+ }
+
+ Tcl_Interp *interp = Tcl_CreateInterp();
+ Tk_Init(interp);
+ Tk_Window tkwin = Tk_MainWindow(interp);
+ Tk_GeometryRequest(tkwin, wsize, wsize);
+ Tk_MakeWindowExist(tkwin);
+ Tk_MapWindow(tkwin);
+
+ /* Note: confirmed with Tcl/Tk community that (at least as of Tcl/Tk 8.6)
+ * Tcl_Eval is the ONLY way to create an image object. The C API just
+ * doesn't expose that ability, although it does support manipulation of
+ * the created object. */
+ std::string img_cmd = std::string("image create photo ") +
std::string(DM_PHOTO);
+ Tcl_Eval(interp, img_cmd.c_str());
+ Tk_PhotoHandle dm_img = Tk_FindPhoto(interp, DM_PHOTO);
+ Tk_PhotoBlank(dm_img);
+ Tk_PhotoSetSize(interp, dm_img, wsize, wsize);
+
+ Tk_PhotoImageBlock dm_data;
+ dm_data.width = wsize;
+ dm_data.height = wsize;
+ dm_data.pixelSize = 4;
+ dm_data.pitch = wsize * 4;
+ dm_data.offset[0] = 0;
+ dm_data.offset[1] = 1;
+ dm_data.offset[2] = 2;
+ dm_data.offset[3] = 3;
+ dm_data.pixelPtr = (unsigned char *)Tcl_AttemptAlloc(dm_data.width *
dm_data.height * 4);
+ if (!dm_data.pixelPtr) {
+ std::cerr << "Tcl/Tk photo memory allocation failed!\n";
+ exit(1);
+ }
+ for (int i = 0; i < (dm_data.width * dm_data.height * 4); i++) {
+ // Initialize the buffer with random values (simulates on-the-fly
+ // buffer generation from a rasterization or raytrace)
+ dm_data.pixelPtr[i] = rgb[i];
+ }
+
+ Tk_PhotoPutBlock(interp, dm_img, &dm_data, 0, 0, wsize, wsize,
TK_PHOTO_COMPOSITE_SET);
+
+ // TODO - examples use a label to pack and display an image - is this the
+ // right way for us to do it in MGED/Archer?
+ std::string label_cmd = std::string("label ") + std::string(DM_LABEL) +
std::string(" -image ") + std::string(DM_PHOTO);
+ Tcl_Eval(interp, label_cmd.c_str());
+ std::string pack_cmd = std::string("pack ") + std::string(DM_LABEL);
+ Tcl_Eval(interp, pack_cmd.c_str());
+
+ std::uniform_int_distribution<int> colors(0,1);
+ while (1) {
+ int handled = 0;
+ while (Tcl_DoOneEvent(TCL_ALL_EVENTS|TCL_DONT_WAIT)) {
+ handled++;
+ }
+ if (!Tk_GetNumMainWindows()) {
+ // If we've closed the window, we're done
+ exit(0);
+ }
+
+ // Generate a new random pattern on the same image
+ update_data(interp, colors(gen), colors(gen), colors(gen));
+ }
+
+}
+
+// Local Variables:
+// tab-width: 8
+// mode: C++
+// c-basic-offset: 4
+// indent-tabs-mode: t
+// c-file-style: "stroustrup"
+// End:
+// ex: shiftwidth=4 tabstop=8
Property changes on: brlcad/trunk/src/libdm/tcl_img.cpp
___________________________________________________________________
Added: svn:eol-style
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+native
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Added: svn:mime-type
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+text/plain
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