Clean Up Build Warnings

Make the `FntPrint` function signature consistent between header and
impl and and put guard around duplicate `CLAMP` macro in `libgpu/sys.c`.

Author: hohle

include/psxsdk/libgpu.h

@@ -600,7 +600,13 @@ extern int SetGraphReverse(int mode);
 extern int SetGraphQueue(int mode);
 extern u_long DrawSyncCallback(void (*func)());
 extern void FntLoad(int tx, int ty);
-int FntPrint(const char* fmt, ...);
+// n.b.! FntPrint has an odd signature where the
+// first arg can be interpretted as a char* or int.
+// the SDK header uses a long, but all uses we've
+// come across so far use a char*. modern compilers
+// are strict about this type of thing, so this
+// doesn't match the docs.
+int FntPrint(char* id, ...);
 extern void SetDispMask(int mask);
 extern void SetDrawMode(DR_MODE* p, int dfe, int dtd, int tpage, RECT* tw);
 extern void SetDumpFnt(int id);

src/main/psxsdk/libgpu/font.c

@@ -178,7 +178,7 @@ u_long* FntFlush(s32 id) {
         return -1;                                                             \
     }
 
-long FntPrint(long id, ...) {
+int FntPrint(char* id, ...) {
     char buf[0x200];
     va_list args;
     FntStream* font;
@@ -192,17 +192,17 @@ long FntPrint(long id, ...) {
     u32 ch;
 
     va_start(args, id);
-    if (id < 0 || id >= D_8002B810) {
+    if (LOW(id) < 0 || LOW(id) >= D_8002B810) {
         f = (char*)id;
         id = D_8002B814;
-        if (Font[id].buffer == NULL) {
+        if (Font[LOW(id)].buffer == NULL) {
             return -1;
         }
     } else {
         f = va_arg(args, char*);
     }
 
-    font = &Font[id];
+    font = &Font[LOW(id)];
     if (font->written > font->capacity) {
         return -1;
     }

src/main/psxsdk/libgpu/sys.c

@@ -65,8 +65,10 @@ static volatile s32* DPCR = (s32*)0x1F8010F0;
 static volatile s32 _qin = 0;
 static volatile s32 _qout = 0;
 
+#ifndef CLAMP
 #define CLAMP(value, low, high)                                                \
     value < low ? low : (value > high ? high : value)
+#endif
 
 // gpu commands
 #define CMD_CLEAR_CACHE 0x01000000

src/pc/psxsdk/libgpu.c

@@ -11,7 +11,7 @@ int FntOpen(int x, int y, int w, int h, int isbg, int n) { NOT_IMPLEMENTED; }
 void FntLoad(int tx, int ty) { NOT_IMPLEMENTED; }
 
 int MyFntPrint(const char* fmt, va_list arg);
-int FntPrint(const char* fmt, ...) {
+int FntPrint(char* fmt, ...) {
     int n;
     va_list args;
     va_start(args, fmt);

src/pc/render_soft.c

@@ -29,9 +29,6 @@ int get_mode(int dfe, int dtd, int tpage);
 u32 get_ofs(s16 arg0, s16 arg1);
 u32 get_tw(RECT* arg0);
 
-#define CLAMP(value, low, high)                                                \
-    value < low ? low : (value > high ? high : value)
-
 u32 D_8002C26C = 0;
 void GPU_Init(bool pal_clock_and_tv);
 void GPU_StartFrameC();