diff options
-rw-r--r-- | src/controller.h | 6 | ||||
-rw-r--r-- | src/platforms/avr/clockless_trinket.h | 12 |
2 files changed, 12 insertions, 6 deletions
diff --git a/src/controller.h b/src/controller.h index fe32d70d..7b7a7cf9 100644 --- a/src/controller.h +++ b/src/controller.h @@ -404,7 +404,11 @@ protected: ///@param nLeds the number of leds being written out ///@param scale the rgb scaling to apply to each led before writing it out virtual void show(const struct CRGB *data, int nLeds, CRGB scale) { - PixelController<RGB_ORDER, LANES, MASK> pixels(data, nLeds, scale, getDither()); + PixelController<RGB_ORDER, LANES, MASK> pixels(data, nLeds < 0 ? -nLeds : nLeds, scale, getDither()); + if(nLeds < 0) { + // nLeds < 0 implies that we want to show them in reverse + pixels.mAdvance = -pixels.mAdvance; + } showPixels(pixels); } diff --git a/src/platforms/avr/clockless_trinket.h b/src/platforms/avr/clockless_trinket.h index 45143d91..49de3b91 100644 --- a/src/platforms/avr/clockless_trinket.h +++ b/src/platforms/avr/clockless_trinket.h @@ -248,13 +248,13 @@ protected: #define PRESCALEB4(D) asm __volatile__("brcc L_%=\n\tldi %[scale_base], 0xFF\n\tL_%=:\n\tneg %[" #D "]\n\tCLC" ASM_VARS); // Clamp for prescale, increment data, since we won't ever wrap 65k, this also effectively clears carry for us -#define PSBIDATA4(D) asm __volatile__("brcc L_%=\n\tldi %[scale_base], 0xFF\n\tL_%=:\n\tadd %A[data], %[ADV]\n\tadc %B[data], __zero_reg__\n\t" ASM_VARS); +#define PSBIDATA4(D) asm __volatile__("brcc L_%=\n\tldi %[scale_base], 0xFF\n\tL_%=:\n\tadd %A[data], %A[ADV]\n\tadc %B[data], %B[ADV]\n\t" ASM_VARS); #else #define PRESCALE4(D) _dc<4>(loopvar); #define PRESCALEA2(D) _dc<2>(loopvar); #define PRESCALEB4(D) _dc<4>(loopvar); -#define PSBIDATA4(D) asm __volatile__( "add %A[data], %[ADV]\n\tadc %B[data], __zero_reg__\n\trjmp .+0\n\t" ASM_VARS ); +#define PSBIDATA4(D) asm __volatile__( "add %A[data], %A[ADV]\n\tadc %B[data], %B[ADV]\n\trjmp .+0\n\t" ASM_VARS ); #endif // 2 cycles - perform one step of the scaling (if a given bit is set in scale, add scale-base to the scratch space) @@ -306,8 +306,8 @@ protected: #define DONE asm __volatile__("2:" ASM_VARS ); // 2 cycles - increment the data pointer -#define IDATA2 asm __volatile__("add %A[data], %[ADV]\n\tadc %B[data], __zero_reg__\n\t" ASM_VARS ); -#define IDATACLC3 asm __volatile__("add %A[data], %[ADV]\n\tadc %B[data], __zero_reg__\n\t" _CLC1 ASM_VARS ); +#define IDATA2 asm __volatile__("add %A[data], %A[ADV]\n\tadc %B[data], %B[ADV]\n\t" ASM_VARS ); +#define IDATACLC3 asm __volatile__("add %A[data], %A[ADV]\n\tadc %B[data], %B[ADV]\n\t" _CLC1 ASM_VARS ); // 1 cycle mov #define _MOV1(B1, B2) "mov %[" #B1 "], %[" #B2 "]\n\t" @@ -375,7 +375,9 @@ protected: pixels.preStepFirstByteDithering(); // pull the dithering/adjustment values out of the pixels object for direct asm access - uint8_t advanceBy = pixels.advanceBy(); + + // even though advanceBy is only an int8, we cast it to int16 for sign extension in case it's negative. + int16_t advanceBy = pixels.advanceBy(); uint16_t count = pixels.mLen; uint8_t s0 = pixels.mScale.raw[RO(0)]; |