Another cool plug-in by brainsucker, a calculator :)

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@2920 212acab6-be3b-0410-9dea-997c60f758d6

Contrib/Math/Source/Math.h

@@ -0,0 +1,87 @@
+#pragma once
+
+#ifdef _DEBUG
+//#define _DEBUG_LEAKS
+#endif
+
+#ifdef _DEBUG_LEAKS
+
+#define dbgGlobalAlloc(a, b) watchGlobalAlloc(a, b)
+#define dbgGlobalFree(a) watchGlobalFree(a)
+#define dbgGlobalCheck() watchGlobal();
+void watchGlobal();
+void watchGlobalFree(HGLOBAL block);
+HGLOBAL watchGlobalAlloc(UINT Flags, UINT size);
+
+#else
+
+#define dbgGlobalAlloc(a, b) GlobalAlloc(a, b)
+#define dbgGlobalFree(a) GlobalFree(a)
+#define dbgGlobalCheck() {};
+
+#endif
+
+
+
+// only include this file from one place in your DLL.
+// (it is all static, if you use it in two places it will fail)
+
+#define Math_INIT()           {  \
+        g_stringsize=string_size; \
+        g_stacktop=stacktop;      \
+        g_variables=variables; }
+
+// For page showing plug-ins
+#define WM_NOTIFY_OUTER_NEXT (WM_USER+0x8)
+#define WM_NOTIFY_CUSTOM_READY (WM_USER+0xd)
+#define NOTIFY_BYE_BYE 'x'
+
+typedef struct _stack_t {
+  struct _stack_t *next;
+  char text[1]; // this should be the length of string_size
+} stack_t;
+
+extern unsigned int g_stringsize;
+extern stack_t **g_stacktop;
+extern char *g_variables;
+
+enum
+{
+INST_0,         // $0
+INST_1,         // $1
+INST_2,         // $2
+INST_3,         // $3
+INST_4,         // $4
+INST_5,         // $5
+INST_6,         // $6
+INST_7,         // $7
+INST_8,         // $8
+INST_9,         // $9
+INST_R0,        // $R0
+INST_R1,        // $R1
+INST_R2,        // $R2
+INST_R3,        // $R3
+INST_R4,        // $R4
+INST_R5,        // $R5
+INST_R6,        // $R6
+INST_R7,        // $R7
+INST_R8,        // $R8
+INST_R9,        // $R9
+INST_CMDLINE,   // $CMDLINE
+INST_INSTDIR,   // $INSTDIR
+INST_OUTDIR,    // $OUTDIR
+INST_EXEDIR,    // $EXEDIR
+INST_LANG,      // $LANGUAGE
+__INST_LAST
+};
+
+
+// utility functions (not required but often useful)
+int popstring(char *str);
+void pushstring(char *str);
+char *getuservariable(int varnum);
+void setuservariable(int varnum, char *var);
+char *AllocString();
+ExpressionItem *AllocItem();
+ExpressionItem *AllocArray(int size);
+ExpressionItem *CopyItem(ExpressionItem *item, int NeedConst = 0);