Adafruit_GFX Compatible Layers - Modern Font Support coming to SmartMatrix Library 4.0

marcmerlin · September 14, 2020, 10:46pm

If yo’u’re trying to replace SmartMatrix::GFX by integrating its FastLED+GFX functionality, by all means. I’ll have no problem turning down my code and pointing to yours.
If you were worried about breaking SmartMatrix::GFX, I don’t think it’s much of a worry. I really only use the pointer to your 2 copies of the framebuffer and poke into them directly as they happen to be compatible between SmartMatrix in 24bit mode, and FastLED.

The cast has not been a problem, all I do is this:

github.com

marcmerlin/SmartMatrix_GFX/blob/7279a21fede3f5a972a206d3bb68f7fed1f02cae/examples/MatrixGFXDemo/MatrixGFXDemo.ino#L53


      
          
          
#define mw kMatrixWidth
          #define mh kMatrixHeight
          #define NUMMATRIX (kMatrixWidth*kMatrixHeight)
          
          
CRGB *matrixleds;
          
          
void show_callback();
          SmartMatrix_GFX *matrix = new SmartMatrix_GFX(matrixleds, mw, mh, show_callback);
          // Sadly this callback function must be copied around with this init code
          void show_callback() {
              backgroundLayer.swapBuffers(true);
              matrixleds = (CRGB *)backgroundLayer.backBuffer();
              matrix->newLedsPtr(matrixleds);
          }
          
          
// ========================== CONFIG END ======================================================
          
          

          
// This could also be defined as matrix->color(255,0,0) but those defines
          // are meant to work for adafruit_gfx backends that are lacking color()

Even shorter, it’s really only
matrixleds = (CRGB *)backgroundLayer.backBuffer();

The direct cast works fine since the arrays are compatible.
Once I have a pointer on your array, I take my FastLED CRGB array and point it to that
matrix->newLedsPtr(matrixleds);
which goes there:

github.com

marcmerlin/Framebuffer_GFX/blob/f3713191d2911c7b7c2315a01f858236fe61b5c6/Framebuffer_GFX.cpp#L86


      
          #if 0
            Serial.println(matrixWidth);
            Serial.println(matrixHeight);
            Serial.println(tilesX);
            Serial.println(tilesY);
            Serial.println(type);
          #endif
          }
          
          
void Framebuffer_GFX::newLedsPtr(CRGB *new_fb_ptr) {
            _fb = new_fb_ptr;
          }
          
          
// Change frequency, or turn off with setfpsfreq
          void Framebuffer_GFX::showfps() {
            static uint32_t time_last = 0;
            static uint32_t last_framecount = 0;
            uint32_t time_now = millis();
          
          
  framecount++;

I didn’t have to do all the work you did, by defining _fb as an array of CRGB, I get all the FastLED goodness without having to re-write any of it

github.com

marcmerlin/Framebuffer_GFX/blob/f3713191d2911c7b7c2315a01f858236fe61b5c6/Framebuffer_GFX.h#L166


      
          
          
protected:
           uint8_t type, tilesX, tilesY;
           uint16_t matrixWidth, matrixHeight;
           uint32_t fpsfreq = FPSFREQ;
          
          
 // Because SmartMatrix uses templates so heavily, its object cannot be passed to us
           // However the main function can create a show function that copies our data from _fb
           // into the SmartMatrix object, and pass that function to us by pointer.
           void (* _show)();
           CRGB *_fb;
          
          
private:
           uint16_t (*remapFn)(uint16_t x, uint16_t y);
           uint32_t numpix;
           uint32_t passThruColor;
           boolean  passThruFlag = false;
          };
          
          
#endif // _FRAMEBUFFER_GFX_H_
          // vim:sts=2:sw=2

Am I missing something?