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Adding getPixelColor for the grid based coordination #12

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Adding getPixelColor for the grid based coordination #12

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b4cf0cd
Update Adafruit_WS2801.h
stetro May 19, 2014
6cbc1ce
Update Adafruit_WS2801.cpp
stetro May 19, 2014
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23 changes: 22 additions & 1 deletion Adafruit_WS2801.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -228,7 +228,28 @@ uint32_t Adafruit_WS2801::getPixelColor(uint16_t n) {
((uint32_t)pixels[ofs] << 16) | ((uint16_t) pixels[ofs + 1] << 8) | pixels[ofs + 2] :
(pixels[ofs] << 8) | ((uint32_t)pixels[ofs + 1] << 16) | pixels[ofs + 2];
}

return 0; // Pixel # is out of bounds
}
// Get pixel color from previously-set pixel (returns packed 32-bit RGB value) using x,y coordinate system:
uint32_t *Adafruit_WS2801::getPixelColor(uint16_t x, uint16_t y) {
static uint32_t result[3];
boolean evenRow = ((y % 2) == 0);
// calculate x offset first
uint16_t ofs = x % width;
if (!evenRow) {
ofs = (width-1) - ofs;
}
// add y offset
ofs += y * width;
result[0]=0;
result[1]=0;
result[2]=0;
if(ofs < numLEDs) {
ofs=ofs * 3;
result[0]=pixels[ofs];
result[1]=pixels[ofs+1];
result[2]=pixels[ofs+2];
}
return result;
}

2 changes: 2 additions & 0 deletions Adafruit_WS2801.h
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Expand Up @@ -45,6 +45,8 @@ class Adafruit_WS2801 {
numPixels(void);
uint32_t
getPixelColor(uint16_t n);
uint32_t *
getPixelColor(uint16_t x, uint16_t y);

private:

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