Fix screen code naming (#59)

* Fix naming for screen code usage. Old names are still available but marked deprecated.

* In the functions that plot actual character to the screen the naming
suggested it would handle PETSCII codes, where in fact is was dealing
with screen codes. These changes make that more clear.

* Fix build instructions when using llvm

* Re-adds the asciiToPetsciicode function and adds a deprecation warning when using LLVM

* Fix deprecation warnings, update doxygen comment, remove deprecation for non-exported function

README.md

@@ -35,6 +35,7 @@ Simple C library for the MEGA65
    ~~~sh
    cd mega65-libc
    cmake -DCMAKE_PREFIX_PATH=$HOME/llvm-mos -B build
+   cd build
    make
    make test # if `xmega65` (Xemu) was in your path when running cmake
    ~~~

include/mega65/fcio.h

@@ -516,14 +516,31 @@ fciInfo* fc_displayFCIFile(char* filename, byte x0, byte y0);
 void fc_plotExtChar(byte x, byte y, byte c);
 
 /**
- * @brief plot petscii character
+ * @brief plot screencode character
  *
  * @param x screen column
  * @param y screen row
  * @param c character code
  * @param color character colour
  * @param exAttr extended attributes
  */
+void fc_plotScreenChar(byte x, byte y, byte c, byte color, byte exAttr);
+
+/**
+ * @deprecated The function name is misleading as the supplied character code
+ *             is expected to be a screen character code, not a PETSCII code.
+ *             Use @ref fc_plotScreenChar(byte, byte, byte, byte, byte) instead.
+ * @brief plot screencode character
+ *
+ * @param x screen column
+ * @param y screen row
+ * @param c character code
+ * @param color character colour
+ * @param exAttr extended attributes
+ */
+#ifdef __clang__
+[[deprecated("Use fc_plotScreenChar() instead.")]]
+#endif
 void fc_plotPetsciiChar(byte x, byte y, byte c, byte color, byte exAttr);
 
 #endif // __MEGA65_FCIO_H

src/fcio.c

@@ -340,7 +340,7 @@ himemPtr fc_allocPalMem(word size)
     return 0;
 }
 
-char asciiToPetscii(byte c)
+char asciiToScreencode(byte c)
 {
     // TODO: could be made much faster with translation table
     if (c == '_') {
@@ -355,7 +355,7 @@ char asciiToPetscii(byte c)
     if (c >= 192) {
         return c - 128;
     }
-    return c;
+    return (char)c;
 }
 
 #ifdef __clang__
@@ -740,7 +740,7 @@ void cr(void)
     }
 }
 
-void fc_plotPetsciiChar(byte x, byte y, byte c, byte color, byte exAttr)
+void fc_plotScreenChar(byte x, byte y, byte c, byte color, byte exAttr)
 {
     word adrOffset;
     adrOffset = (x * 2) + (y * 2 * gScreenColumns);
@@ -750,6 +750,11 @@ void fc_plotPetsciiChar(byte x, byte y, byte c, byte color, byte exAttr)
     lpoke(gFcioConfig->colourBase + adrOffset, 0);
 }
 
+void fc_plotPetsciiChar(byte x, byte y, byte c, byte color, byte exAttr)
+{
+    fc_plotScreenChar(x, y, c, color, exAttr);
+}
+
 byte fc_wherex(void)
 {
     return gCurrentWin->xc;
@@ -780,9 +785,9 @@ void fc_putc(char c)
         return;
     }
 
-    out = asciiToPetscii(c);
+    out = asciiToScreencode((byte)c);
 
-    fc_plotPetsciiChar(gCurrentWin->xc + gCurrentWin->x0,
+    fc_plotScreenChar(gCurrentWin->xc + gCurrentWin->x0,
         gCurrentWin->yc + gCurrentWin->y0, out, gCurrentWin->textcolor,
         gCurrentWin->extAttributes);
     gCurrentWin->xc++;
@@ -799,7 +804,7 @@ void fc_putc(char c)
     }
 
     if (csrflag) {
-        fc_plotPetsciiChar(gCurrentWin->xc + gCurrentWin->x0,
+        fc_plotScreenChar(gCurrentWin->xc + gCurrentWin->x0,
             gCurrentWin->yc + gCurrentWin->y0, CURSOR_CHARACTER,
             gCurrentWin->textcolor, 16);
     }
@@ -848,7 +853,7 @@ void fc_cursor(byte onoff)
 {
     csrflag = onoff;
 
-    fc_plotPetsciiChar(gCurrentWin->xc + gCurrentWin->x0,
+    fc_plotScreenChar(gCurrentWin->xc + gCurrentWin->x0,
         gCurrentWin->yc + gCurrentWin->y0, (csrflag ? CURSOR_CHARACTER : 32),
         gCurrentWin->textcolor, (csrflag ? 16 : 0));
 }