From d00096fe2ea3dd64cff9878879c077f23a783e4a Mon Sep 17 00:00:00 2001
From: Matthew Wozniak <me@woz.blue>
Date: Sun, 3 Nov 2024 00:16:00 -0400
Subject: find videomode

---
 api.c | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

(limited to 'api.c')

diff --git a/api.c b/api.c
index 8001f8f..b24514e 100644
--- a/api.c
+++ b/api.c
@@ -10,18 +10,28 @@
 
 struct engserver *engserver = NULL;
 struct engclient *engclient = NULL;
+struct engineapi *engineapi = NULL;
+struct enginetools *enginetools = NULL;
 struct demoplayer *demoplayer = NULL;
+struct videomode **videomode = NULL;
+struct movieinfo *movieinfo = NULL;
 void (*cbuf_addtext)(char *) = NULL;
 
+// TODO: should this be split up?
+
 bool api_init(void) {
 	void *engine_dll = os_dlhandle("engine");
 	createinterface_func engine_factory =
 		(createinterface_func)os_dlsym(engine_dll, "CreateInterface");
 	if (!engine_factory) bail("couldn't get engine factory");
-	engserver = engine_factory(INTERFACEVERSION_VENGINESERVER, NULL);
+	engserver = engine_factory(VENGINE_SERVER_INTERFACE_VERSION, NULL);
 	if (!engserver) bail("couldn't get IVEngineServer from engine");
 	engclient = engine_factory(VENGINE_CLIENT_INTERFACE_VERSION, NULL);
 	if (!engclient) bail("couldn't get IVEngineClient from engine");
+	engineapi = engine_factory(VENGINE_LAUNCHER_INTERFACE_VERSION, NULL);
+	if (!engineapi) bail("couldn't get IEngineAPI from engine");
+	enginetools = engine_factory(VENGINE_TOOL_INTERFACE_VERSION, NULL);
+	if (!engineapi) bail("couldn't get IEngineTools from engine");
 
 	// find cbuf_addtext
 	const u8 *instr = (const u8 *)engserver->vt->server_command;
@@ -41,13 +51,31 @@ bool api_init(void) {
 
 	// find demoplayer
 	instr = (const u8 *)engclient->vt->is_playing_demo;
-	debug("is_playing_demo = %p", (void *)instr); 
 	// CEngineClient::IsPlayingDemo is a wrapper around a demoplayer call
-	// The first thing it does should be load demoplayer into ECX
+	// The first thing it does should be load a ptr to demoplayer into ECX
 	if (instr[0] != X86_MOVRMW || instr[1] != X86_MODRM(0, 1, 5))
 		bail("couldn't get demoplayer");
 	demoplayer = **(struct demoplayer ***)(instr + 2);
 	debug("demoplayer = %p", (void *)demoplayer);
+
+	// find videomode
+	// CEngineAPI::SetEngineWindow calls videomode->SetGameWindow after
+	// detaching the current window with another vcall. Look for the second one.
+	// This, like the demoplayer, is a pointer. Mind the double dereference.
+	instr = (const u8 *)engineapi->vt->set_engine_window;
+	int mov_ecx_counter = 0;
+	for (const u8 *p = instr; p - instr < 64;) {
+		if (p[0] == X86_MOVRMW && p[1] == X86_MODRM(0, 1, 5)
+				&& ++mov_ecx_counter == 2) {
+			videomode = *(struct videomode ***)(p + 2);
+			break;
+		}
+		int l = x86_len(p);
+		if (l == -1)
+			bail("invalid instruction looking for videomode");
+		p += l;
+	}
+	debug("videomode = %p", (void *)videomode);
 	
 	return true;
 }
-- 
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