implement buffer with pixel operations

twinmax/display.cpp

@@ -52,6 +52,7 @@ void Display::send_commands(const uint8_t *cc, uint8_t n){
 Display::Display(const uint8_t resetPin){
 	_rstPin = resetPin;
 	_wire = &Wire;
+	_buffer = (uint8_t*) malloc(_width * ((_height + 7) / 8));
 }
 
 void Display::begin(){
@@ -118,7 +119,29 @@ void Display::begin(){
 	return;
 }
 
+#define swap(a, b) \
+  (((a) ^= (b)), ((b) ^= (a)), ((a) ^= (b))) ///< No-temp-var swap operation
+
 void Display::clear(){
+	memset(_buffer, 0, _width * ((_height + 7) / 8));
+}
+
+void Display::setPixel(int16_t x, int16_t y, const bool white){
+	if( x > _width || y > _height || x < 0 || y < 0 ){
+		return;
+	}
+	// swap(x, y);
+	// x = _width  - x - 1;
+	// y = _height - y - 1;
+
+	if( white ){
+		_buffer[x + (y/8)*_width] |= (1 << (y&7));
+		return;
+	}
+	_buffer[x + (y/8)*_width] &= ~(1 << (y&7));
+}
+
+void Display::apply(){
 	TRANSACTION_START
 
 	static const uint8_t PROGMEM dlist1[] = {
@@ -131,9 +154,10 @@ void Display::clear(){
 	send_commands(dlist1, sizeof(dlist1));
 	send_command(_width - 1); // Column end address
 
+	uint16_t count = _width * ((_height + 7) / 8);
+	uint8_t* ptr   = _buffer;
 	_wire->beginTransmission(_i2caddr);
 	_wire->write((uint8_t) 0x40);
-	uint16_t count   = _width * ((_height + 7) / 8);
 	uint8_t written = 1;
 	while(count--){
 		if( written >= WIRE_MAX ){
@@ -142,15 +166,65 @@ void Display::clear(){
 			_wire->write((uint8_t) 0x40);
 			written = 1;
 		}
-		_wire->write(0);
+		_wire->write(*ptr++);
+		written++;
 	}
 	_wire->endTransmission();
 
 	TRANSACTION_END
 }
 
+void Display::setTitle(const String title){
+	// todo
+}
+
 // draws a progress bar to a fixed location
-// the progress value is between 0 and 255
-void Display::progress(const uint8_t progress){
+// the progress value is between 0 and 1023
+void Display::progress(const short progress, const uint8_t startLine, const uint8_t endLine, const bool absolute){
+	// top line
+	for( uint8_t i = 0 ; i < 128 ; i++ ){
+		setPixel(i, startLine, true);
+	}
+
+	// bottom line
+	for( uint8_t i = 0 ; i < 128 ; i++ ){
+		setPixel(i, endLine, true);
+	}
+
+	// center tip
+	for( uint8_t i = startLine+2 ; i < endLine-1 ; i++ ){
+		setPixel(64, endLine, true);
+	}
+
+	uint16_t scaledProgress = (progress+7) / 8;
+
+	// draw absolute progression
+	if( absolute ){
+		for( uint8_t x = 0 ; x < scaledProgress ; x++ ){
+			for( uint8_t y = startLine+1 ; y < endLine ; y++ ){
+				setPixel(x, y, true);
+			}
+		}
+		return;
+	}
+
+	// draw left relative progression
+	if( progress < 512 ){
+
+		for( uint8_t x = scaledProgress ; x < 64 ; x++ ){
+			for( uint8_t y = startLine+1 ; y < endLine ; y++ ){
+				setPixel(x, y, true);
+			}
+		}
+
+	// draw right relative progression
+	} else {
+
+		for( uint8_t x = 64 ; x < scaledProgress ; x++ ){
+			for( uint8_t y = startLine+1 ; y < endLine ; y++ ){
+				setPixel(x, y, true);
+			}
+		}
 
 	}
+}

twinmax/display.h

@@ -49,14 +49,18 @@
 			Display(const uint8_t resetPin=-1);
 			void begin();
 			void clear();
-			void progress(const uint8_t progress);
+			void setTitle(const String title);
+			void setPixel(int16_t x, int16_t y, const bool white=true);
+			void progress(const short progress, const uint8_t startLine, const uint8_t endLine, const bool absolute=true);
+			void apply();
 
 		protected:
 			void send_command(const uint8_t c);
 			void send_commands(const uint8_t *cc, const uint8_t n);
 		private:
-			const uint8_t _width    { 128  };
-			const uint8_t _height   { 32   };
+			const static int16_t _width  { 128  };
+			const static int16_t _height { 32   };
+			uint8_t* _buffer { nullptr };
 			const uint8_t _comPin   { 0x02 };
 			const uint8_t _i2caddr  { 0x3C };
 			const uint8_t _contrast { 0x8F };