# HG changeset patch
# User František Kučera <franta-hg@frantovo.cz>
# Date 1513959315 -3600
# Node ID 2ab3d728224939e046005869b5616dfa3fdd8481
# Parent  2a4b8b3abe14415f87f3fe161007c485a3cf625f
INCREMENT, DECREMENT

diff -r 2a4b8b3abe14 -r 2ab3d7282249 c++/rgb-assembler/rgb-assembler.cpp
--- a/c++/rgb-assembler/rgb-assembler.cpp	Fri Dec 22 16:21:10 2017 +0100
+++ b/c++/rgb-assembler/rgb-assembler.cpp	Fri Dec 22 17:15:15 2017 +0100
@@ -10,6 +10,7 @@
 using namespace std;
 
 typedef uint16_t address_t;
+typedef uint8_t byte_t;
 typedef uint8_t command_t;
 typedef uint8_t sleep_t;
 typedef uint8_t color_t;
@@ -46,6 +47,18 @@
 const command_t CMD_END = 0xED;
 
 /**
+ * Increase value at given address
+ * parameter: address_t
+ */
+const command_t CMD_INCREMENT = 0x11;
+
+/**
+ * Decrease value at given address
+ * parameter: address_t
+ */
+const command_t CMD_DECREMENT = 0x12;
+
+/**
  * Placeholder for unsupported command.
  * Just for testing.
  */
@@ -54,30 +67,30 @@
 /**
  * Reads data on given position in memory and increments the index (position).
  */
-template<typename T> T read(command_t * memory, address_t &index) {
+template<typename T> T read(byte_t * memory, address_t &index) {
 	// TODO: for addresses: map higher memory to static hardcoded areas or peripherals
-	// TODO: sizeof (command_t) != 1 ?
+	// TODO: sizeof (byte_t) != 1 ?
 	T * value = reinterpret_cast<T*> (memory + index);
-	index += sizeof (*value) / sizeof (command_t);
+	index += sizeof (*value) / sizeof (byte_t);
 	return *value;
 }
 
 /**
  * Writes data to given position in memory and increments the index (position).
  */
-template<typename T> void write(command_t * memory, address_t &index, const T value) {
-	// TODO: sizeof (command_t) != 1 ?
+template<typename T> void write(byte_t * memory, address_t &index, const T value) {
+	// TODO: sizeof (byte_t) != 1 ?
 	// T * m = (T*) (memory + index);
 	T * m = reinterpret_cast<T*> (memory + index);
 	*m = value;
-	index += sizeof (value) / sizeof (command_t);
+	index += sizeof (value) / sizeof (byte_t);
 }
 
 int main(int argc, char* argv[]) {
 
 	setlocale(LC_ALL, "");
 
-	command_t * memory = (command_t*) malloc(MEMORY_SIZE);
+	byte_t * memory = (byte_t*) malloc(MEMORY_SIZE);
 
 	{
 		address_t a = 0;
@@ -98,6 +111,10 @@
 		write<color_t>(memory, a, 0);
 		write<color_t>(memory, a, 200);
 		write<color_t>(memory, a, 255);
+		write<command_t>(memory, a, CMD_INCREMENT);
+		write<address_t>(memory, a, 0);
+		write<command_t>(memory, a, CMD_DECREMENT);
+		write<address_t>(memory, a, 0);
 		write<command_t>(memory, a, CMD_END);
 	}
 
@@ -129,6 +146,18 @@
 				wprintf(L"COLOR  %02X %02X %02X → %d\n", r, g, b, led);
 				break;
 			}
+			case CMD_INCREMENT:
+			case CMD_DECREMENT:
+			{
+				address_t address = read<address_t>(memory, i);
+				address_t address_r = address;
+				address_t address_w = address_r;
+				byte_t value = read<byte_t>(memory, address_r);
+				value = ch == CMD_INCREMENT ? value + 1 : value - 1;
+				write<byte_t>(memory, address_w, value);
+				wprintf(L"%sCREMENT %*d → %02X\n", (ch == CMD_INCREMENT ? "IN" : "DE"), 5, address, value);
+				break;
+			}
 			case CMD_END:
 			{
 				wprintf(L"END\n");