Vmapper

examples-api-use/README.md

@@ -291,6 +291,40 @@ two chains with 8 panels each
 
 (`--led-chain=8 --led-parallel=2 --led-pixel-mapper="U-mapper"`).
 
+#### V-mapper
+
+By default, when you add panels on a chain, they are added horizontally.  
+If you have 2 panels of 64x32, you get 128x32. What if you wanted 64x64?  
+V-mapper allows the stacking to be vertical and not horizontal.
+
+It is compatible with parallel output, so if you have 12 128x64 panels, without this
+mapper, you can either do a matrix of 3x3 panels (384x192). Adding more panels
+would force you to have a 4x3 layout (512x192) while you probably want a 3x4
+layout (384 * 256) for a better aspect ratio.
+
+```
+  ./demo --led-rows=64 --led-cols=128 --led-chain=4 -led-parallel=3 --led-pixel-mapper=V-mapper -D0
+```
+
+Note that this is not a U mapper, all the panels are correct side up, and you need
+more cable length. It looks like this, 3 chains of 4 panels for a total of 32K pixels
+per chain. This is also a good time to mention that this is probably an upper limit of
+what you can reasonably output without having an unusable fresh rate
+( Try these options to help: --led-pwm-bits=7 --led-pwm-dither-bits=1 and get about 100Hz )
+
+```
+  [O < I] [O < I] [O < I]
+   ,---'   ,---'   ,---'
+  [O < I] [O < I] [O < I]
+   ,---'   ,---'   ,---'
+  [O < I] [O < I] [O < I]
+   ,---'   ,---'   ,---'
+  [O < I] [O < I] [O < I]
+       ^       ^       ^
+      Ch1     Ch2     Ch3
+```
+
+
 #### Rotate
 
 The "Rotate" mapper allows you to rotate your screen. It takes an angle
@@ -387,4 +421,4 @@ line option in C++ and Python.
 [git-submodules]: http://git-scm.com/book/en/Git-Tools-Submodules
 [pixelpush]: https://github.com/hzeller/rpi-matrix-pixelpusher
 [pp-vid]: ../img/pixelpusher-vid.jpg
-[otf2bdf]: https://github.com/jirutka/otf2bdf
+[otf2bdf]: https://github.com/jirutka/otf2bdf

lib/pixel-mapper.cc

@@ -217,6 +217,50 @@ class UArrangementMapper : public PixelMapper {
   int parallel_;
 };
 
+
+
+class VerticalMapper : public PixelMapper {
+public:
+  VerticalMapper() {}
+
+  virtual const char *GetName() const { return "V-mapper"; }
+
+  virtual bool SetParameters(int chain, int parallel, const char *param) {
+    chain_ = chain;
+    parallel_ = parallel;
+    return true;
+  }
+
+  virtual bool GetSizeMapping(int matrix_width, int matrix_height,
+                              int *visible_width, int *visible_height)
+    const {
+    *visible_width = matrix_width * parallel_ / chain_;
+    *visible_height = matrix_height * chain_ / parallel_;
+      fprintf(stderr, "%s: C:%d P:%d. Turning W:%d H:%d Physical "
+	      "into W:%d H:%d Virtual\n",
+              GetName(), chain_, parallel_,
+	      *visible_width, *visible_height, matrix_width, matrix_height);
+    return true;
+  }
+
+  virtual void MapVisibleToMatrix(int matrix_width, int matrix_height,
+                                  int x, int y,
+                                  int *matrix_x, int *matrix_y) const {
+    int panel_width  = matrix_width  / chain_;
+    int panel_height = matrix_height / parallel_;
+    *matrix_x = (x % panel_width) +  int(y/panel_height)* panel_width;
+    *matrix_y = (y % panel_height) + int(x/panel_width) * panel_height;
+
+    //fprintf(stderr, "%s: Panel-W:%d Panel-H:%d. X: %3d -> %3d, Y: %3d -> %3d\n",
+    //          GetName(), panel_width, panel_height, x, *matrix_x, y, *matrix_y);
+  }
+
+private:
+  int chain_;
+  int parallel_;
+};
+
+
 typedef std::map<std::string, PixelMapper*> MapperByName;
 static void RegisterPixelMapperInternal(MapperByName *registry,
                                         PixelMapper *mapper) {
@@ -233,6 +277,7 @@ static MapperByName *CreateMapperMap() {
   // Register all the default PixelMappers here.
   RegisterPixelMapperInternal(result, new RotatePixelMapper());
   RegisterPixelMapperInternal(result, new UArrangementMapper());
+  RegisterPixelMapperInternal(result, new VerticalMapper());
   RegisterPixelMapperInternal(result, new MirrorPixelMapper());
   return result;
 }