Core: Fix frameskip

src/gb/core.c

@@ -71,6 +71,7 @@ static void _GBCoreLoadConfig(struct mCore* core, const struct mCoreConfig* conf
 
 	struct GB* gb = core->board;
 	gb->audio.masterVolume = core->opts.volume;
+	gb->video.frameskip = core->opts.frameskip;
 }
 
 static void _GBCoreDesiredVideoDimensions(struct mCore* core, unsigned* width, unsigned* height) {

src/gb/video.c

@@ -93,7 +93,9 @@ int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles) {
 			int lyc = video->p->memory.io[REG_LYC];
 			switch (video->mode) {
 			case 0:
+				if (video->frameskipCounter <= 0) {
 					video->renderer->finishScanline(video->renderer, video->ly);
+				}
 				++video->ly;
 				video->p->memory.io[REG_LY] = video->ly;
 				video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
@@ -106,9 +108,13 @@ int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles) {
 				} else {
 					video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
 					video->mode = 1;
-					++video->frameCounter;
+					--video->frameskipCounter;
+					if (video->frameskipCounter < 0) {
 						video->renderer->finishFrame(video->renderer);
 						mCoreSyncPostFrame(video->p->sync);
+						video->frameskipCounter = video->frameskip;
+					}
+					++video->frameCounter;
 
 					struct mCoreThread* thread = mCoreThreadGet();
 					if (thread && thread->frameCallback) {
@@ -214,8 +220,10 @@ void GBVideoProcessDots(struct GBVideo* video) {
 	if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
 		video->dotCounter = INT_MIN;
 	}
+	if (video->frameskipCounter <= 0) {
 		video->renderer->drawRange(video->renderer, oldX, video->x, video->ly, video->objThisLine, video->objMax);
 	}
+}
 
 void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value) {
 	if (!GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && GBRegisterLCDCIsEnable(value)) {

src/gba/core.c

@@ -78,6 +78,7 @@ static void _GBACoreSetSync(struct mCore* core, struct mCoreSync* sync) {
 static void _GBACoreLoadConfig(struct mCore* core, const struct mCoreConfig* config) {
 	struct GBA* gba = core->board;
 	gba->audio.masterVolume = core->opts.volume;
+	gba->video.frameskip = core->opts.frameskip;
 
 #if !defined(MINIMAL_CORE) || MINIMAL_CORE < 2
 	struct GBACore* gbacore = (struct GBACore*) core;

src/platform/commandline.c

@@ -65,6 +65,8 @@ bool parseArguments(struct mArguments* args, int argc, char* const* argv, struct
 #endif
 	;
 	memset(args, 0, sizeof(*args));
+	args->frameskip = -1;
+	args->logLevel = INT_MIN;
 	if (subparser && subparser->extraOptions) {
 		// TODO: modularize options to subparsers
 		strncat(options, subparser->extraOptions, sizeof(options) - strlen(options) - 1);
@@ -136,9 +138,15 @@ bool parseArguments(struct mArguments* args, int argc, char* const* argv, struct
 }
 
 void applyArguments(struct mArguments* args, struct mSubParser* subparser, struct mCoreConfig* config) {
+	if (args->frameskip >= 0) {
 		mCoreConfigSetOverrideIntValue(config, "frameskip", args->frameskip);
+	}
+	if (args->logLevel > INT_MIN) {
 		mCoreConfigSetOverrideIntValue(config, "logLevel", args->logLevel);
+	}
+	if (args->bios) {
 		mCoreConfigSetOverrideValue(config, "bios", args->bios);
+	}
 	if (subparser) {
 		subparser->apply(subparser, config);
 	}