Add droplay example program from /research, adapted to work with OPL

library.

Subversion-branch: /branches/opl-branch
Subversion-revision: 1535

2 files changed, 185 insertions, 0 deletions

diff --git a/opl/examples/Makefile.am b/opl/examples/Makefile.am
new file mode 100644
index 00000000..3dc07d46
--- /dev/null
+++ b/opl/examples/Makefile.am
@@ -0,0 +1,8 @@
+
+AM_CFLAGS = -I..
+
+noinst_PROGRAMS=droplay
+
+droplay_LDADD = ../libopl.a @LDFLAGS@ @SDL_LIBS@
+droplay_SOURCES = droplay.c
+
diff --git a/opl/examples/droplay.c b/opl/examples/droplay.c
new file mode 100644
index 00000000..7cd595e9
--- /dev/null
+++ b/opl/examples/droplay.c
@@ -0,0 +1,177 @@
+// Emacs style mode select   -*- C++ -*- 
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 Simon Howard
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+//     Demonstration program for OPL library to play back DRO
+//     format files.
+//
+//-----------------------------------------------------------------------------
+
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "SDL.h"
+
+#include "opl.h"
+
+#define HEADER_STRING "DBRAWOPL"
+#define ADLIB_PORT 0x388
+
+void WriteReg(unsigned int reg, unsigned int val)
+{
+    int i;
+
+    OPL_WritePort(OPL_REGISTER_PORT, reg);
+
+    for (i=0; i<6; ++i)
+    {
+        OPL_ReadPort(OPL_REGISTER_PORT);
+    }
+
+    OPL_WritePort(OPL_DATA_PORT, val);
+
+    for (i=0; i<35; ++i)
+    {
+        OPL_ReadPort(OPL_REGISTER_PORT);
+    }
+}
+
+void ClearAllRegs(void)
+{
+    int i;
+
+    for (i=0; i<=0xff; ++i)
+    {
+	WriteReg(i, 0x00);
+    }
+}
+
+// Detect an OPL chip.
+
+int DetectOPL(void)
+{
+    WriteReg(OPL_REG_TIMER_CTRL, 0x60);
+    WriteReg(OPL_REG_TIMER_CTRL, 0x80);
+    int val1 = OPL_ReadPort(OPL_REGISTER_PORT) & 0xe0;
+    WriteReg(OPL_REG_TIMER1, 0xff);
+    WriteReg(OPL_REG_TIMER_CTRL, 0x21);
+    SDL_Delay(50);
+    int val2 = OPL_ReadPort(OPL_REGISTER_PORT) & 0xe0;
+    WriteReg(OPL_REG_TIMER_CTRL, 0x60);
+    WriteReg(OPL_REG_TIMER_CTRL, 0x80);
+
+    return val1 != 0 || val2 != 0xc0;
+}
+
+void Init(void)
+{
+    if (SDL_Init(SDL_INIT_TIMER) < 0)
+    {
+        fprintf(stderr, "Unable to initialise SDL timer\n");
+        exit(-1);
+    }
+
+    if (!OPL_Init(ADLIB_PORT))
+    {
+        fprintf(stderr, "Unable to initialise OPL layer\n");
+        exit(-1);
+    }
+
+    if (!DetectOPL())
+    {
+        fprintf(stderr, "Adlib not detected\n");
+        exit(-1);
+    }
+}
+
+void Shutdown(void)
+{
+    OPL_Shutdown();
+}
+
+void PlayFile(char *filename)
+{
+    FILE *stream;
+    char buf[8];
+
+    stream = fopen(filename, "rb");
+
+    if (fread(buf, 1, 8, stream) < 8)
+    {
+        fprintf(stderr, "failed to read raw OPL header\n");
+        exit(-1);
+    }
+
+    if (strncmp(buf, HEADER_STRING, 8) != 0)
+    {
+        fprintf(stderr, "Raw OPL header not found\n");
+        exit(-1);
+    }
+
+    fseek(stream, 28, SEEK_SET);
+
+    while (!feof(stream))
+    {
+        int reg, val;
+
+        reg = fgetc(stream);
+        val = fgetc(stream);
+
+        // Delay?
+
+        if (reg == 0x00)
+        {
+            SDL_Delay(val);
+        }
+        else if (reg == 0x01)
+        {
+            val |= (fgetc(stream) << 8);
+            SDL_Delay(val);
+        }
+        else
+        {
+            WriteReg(reg, val);
+        }
+    }
+
+    fclose(stream);
+}
+
+int main(int argc, char *argv[])
+{
+    if (argc < 2)
+    {
+        printf("Usage: %s <filename>\n", argv[0]);
+        exit(-1);
+    }
+
+    Init();
+    ClearAllRegs();
+    SDL_Delay(1000);
+
+    PlayFile(argv[1]);
+
+    ClearAllRegs();
+    Shutdown();
+
+    return 0;
+}
+