Load and bind divaio at runtime

divahook/diva-dll.c

@@ -0,0 +1,121 @@
+#include <windows.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "divahook/diva-dll.h"
+
+#include "util/dll-bind.h"
+#include "util/dprintf.h"
+
+const struct dll_bind_sym diva_dll_syms[] = {
+    {
+        .sym = "diva_io_jvs_init",
+        .off = offsetof(struct diva_dll, jvs_init),
+    }, {
+        .sym = "diva_io_jvs_poll",
+        .off = offsetof(struct diva_dll, jvs_poll),
+    }, {
+        .sym = "diva_io_jvs_read_coin_counter",
+        .off = offsetof(struct diva_dll, jvs_read_coin_counter),
+    }, {
+        .sym = "diva_io_jvs_set_coin_blocker",
+        .off = offsetof(struct diva_dll, jvs_set_coin_blocker),
+    }, {
+        .sym = "diva_io_slider_init",
+        .off = offsetof(struct diva_dll, slider_init),
+    }, {
+        .sym = "diva_io_slider_start",
+        .off = offsetof(struct diva_dll, slider_start),
+    }, {
+        .sym = "diva_io_slider_stop",
+        .off = offsetof(struct diva_dll, slider_stop),
+    }, {
+        .sym = "diva_io_slider_set_leds",
+        .off = offsetof(struct diva_dll, slider_set_leds),
+    }
+};
+
+struct diva_dll diva_dll;
+
+// Copypasta DLL binding and diagnostic message boilerplate.
+// Not much of this lends itself to being easily factored out. Also there
+// will be a lot of API-specific branching code here eventually as new API
+// versions get defined, so even though these functions all look the same
+// now this won't remain the case forever.
+
+HRESULT diva_dll_init(const struct diva_dll_config *cfg, HINSTANCE self)
+{
+    uint16_t (*get_api_version)(void);
+    const struct dll_bind_sym *sym;
+    HINSTANCE owned;
+    HINSTANCE src;
+    HRESULT hr;
+
+    assert(cfg != NULL);
+    assert(self != NULL);
+
+    if (cfg->path[0] != L'\0') {
+        owned = LoadLibraryW(cfg->path);
+
+        if (owned == NULL) {
+            hr = HRESULT_FROM_WIN32(GetLastError());
+            dprintf("Diva IO: Failed to load IO DLL: %x: %S\n",
+                    hr,
+                    cfg->path);
+
+            goto end;
+        }
+
+        dprintf("Diva IO: Using custom IO DLL: %S\n", cfg->path);
+        src = owned;
+    } else {
+        owned = NULL;
+        src = self;
+    }
+
+    get_api_version = (void *) GetProcAddress(src, "diva_io_get_api_version");
+
+    if (get_api_version != NULL) {
+        diva_dll.api_version = get_api_version();
+    } else {
+        diva_dll.api_version = 0x0100;
+        dprintf("Custom IO DLL does not expose diva_io_get_api_version, "
+                "assuming API version 1.0.\n"
+                "Please ask the developer to update their DLL.\n");
+    }
+
+    if (diva_dll.api_version >= 0x0200) {
+        hr = E_NOTIMPL;
+        dprintf("Diva IO: Custom IO DLL implements an unsupported "
+                "API version (%#04x). Please update Segatools.\n",
+                diva_dll.api_version);
+
+        goto end;
+    }
+
+    sym = diva_dll_syms;
+    hr = dll_bind(&diva_dll, src, &sym, _countof(diva_dll_syms));
+
+    if (FAILED(hr)) {
+        if (src != self) {
+            dprintf("Diva IO: Custom IO DLL does not provide function "
+                    "\"%s\". Please contact your IO DLL's developer for "
+                    "further assistance.\n",
+                    sym->sym);
+
+            goto end;
+        } else {
+            dprintf("Internal error: could not reflect \"%s\"\n", sym->sym);
+        }
+    }
+
+    owned = NULL;
+
+end:
+    if (owned != NULL) {
+        FreeLibrary(owned);
+    }
+
+    return hr;
+}