Add Half Skip Mode. May help #18607

hrydgard · Sep 17, 2024 · cf753ff · cf753ff
1 parent 0bb69a0
commit cf753ff
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Showing 4 changed files with 32 additions and 6 deletions.
diff --git a/Core/Config.h b/Core/Config.h
@@ -245,7 +245,7 @@ struct Config {
 	float fCwCheatScrollPosition;
 	float fGameListScrollPosition;
 	int iBloomHack; //0 = off, 1 = safe, 2 = balanced, 3 = aggressive
-	int iSkipGPUReadbackMode;  // 0 = off, 1 = skip, 2 = to texture
+	int iSkipGPUReadbackMode;  // 0 = off, 1 = skip, 2 = to texture, 3 = half skip
 	int iSplineBezierQuality; // 0 = low , 1 = Intermediate , 2 = High
 	bool bHardwareTessellation;
 	bool bShaderCache;  // Hidden ini-only setting, useful for debugging shader compile times.

diff --git a/Core/ConfigValues.h b/Core/ConfigValues.h
@@ -188,6 +188,7 @@ enum class SkipGPUReadbackMode : int {
 	NO_SKIP,
 	SKIP,
 	COPY_TO_TEXTURE,
+	HALF_SKIP,
 };
 
 enum class RemoteISOShareType : int {

diff --git a/GPU/Common/FramebufferManagerCommon.cpp b/GPU/Common/FramebufferManagerCommon.cpp
@@ -50,6 +50,16 @@
 #include "GPU/GPUInterface.h"
 #include "GPU/GPUState.h"
 
+static bool GenerateBoolean() {
+	int randomNumber = rand() % 100;  // Generate a random number between 0 and 99
+	if (randomNumber < 50) {
+		return true;  // 50% chance of returning true
+	}
+	else {
+		return false;  // 50% chance of returning false
+	}
+}
+
 static size_t FormatFramebufferName(const VirtualFramebuffer *vfb, char *tag, size_t len) {
 	return snprintf(tag, len, "FB_%08x_%08x_%dx%d_%s", vfb->fb_address, vfb->z_address, vfb->bufferWidth, vfb->bufferHeight, GeBufferFormatToString(vfb->fb_format));
 }
@@ -1046,8 +1056,8 @@ void FramebufferManagerCommon::DownloadFramebufferOnSwitch(VirtualFramebuffer *v
 		// To support this, we save the first frame to memory when we have a safe w/h.
 		// Saving each frame would be slow.
 
-		// TODO: This type of download could be made async, for less stutter on framebuffer creation.
-		if (GetSkipGPUReadbackMode() == SkipGPUReadbackMode::NO_SKIP && !PSP_CoreParameter().compat.flags().DisableFirstFrameReadback) {
+		// TODO: This type of download could be made async, for less stutter on framebuffer creation.		
+		if (g_Config.iSkipGPUReadbackMode == (int)SkipGPUReadbackMode::NO_SKIP || (g_Config.iSkipGPUReadbackMode == (int)SkipGPUReadbackMode::HALF_SKIP && GenerateBoolean())) {
 			ReadFramebufferToMemory(vfb, 0, 0, vfb->safeWidth, vfb->safeHeight, RASTER_COLOR, Draw::ReadbackMode::BLOCK);
 			vfb->usageFlags = (vfb->usageFlags | FB_USAGE_DOWNLOAD | FB_USAGE_FIRST_FRAME_SAVED) & ~FB_USAGE_DOWNLOAD_CLEAR;
 			vfb->safeWidth = 0;
@@ -1063,10 +1073,25 @@ bool FramebufferManagerCommon::ShouldDownloadFramebufferColor(const VirtualFrame
 
 bool FramebufferManagerCommon::ShouldDownloadFramebufferDepth(const VirtualFramebuffer *vfb) {
 	// Download depth buffer for Syphon Filter lens flares
-	if (!PSP_CoreParameter().compat.flags().ReadbackDepth || GetSkipGPUReadbackMode() != SkipGPUReadbackMode::NO_SKIP) {
+	if (!PSP_CoreParameter().compat.flags().ReadbackDepth) {
 		return false;
 	}
-	return (vfb->usageFlags & FB_USAGE_RENDER_DEPTH) != 0 && vfb->width >= 480 && vfb->height >= 272;
+
+	bool performDepthReadback = true;
+
+	switch (GetSkipGPUReadbackMode()) {
+	case SkipGPUReadbackMode::SKIP:
+		performDepthReadback = false;
+		break;
+	case SkipGPUReadbackMode::HALF_SKIP:
+		performDepthReadback = GenerateBoolean();
+		break;
+	case SkipGPUReadbackMode::COPY_TO_TEXTURE:
+	case SkipGPUReadbackMode::NO_SKIP:
+		break;
+	}
+
+	return performDepthReadback && (vfb->usageFlags & FB_USAGE_RENDER_DEPTH) != 0 && vfb->width >= 480 && vfb->height >= 272;
 }
 
 void FramebufferManagerCommon::NotifyRenderFramebufferSwitched(VirtualFramebuffer *prevVfb, VirtualFramebuffer *vfb, bool isClearingDepth) {

diff --git a/UI/GameSettingsScreen.cpp b/UI/GameSettingsScreen.cpp
@@ -441,7 +441,7 @@ void GameSettingsScreen::CreateGraphicsSettings(UI::ViewGroup *graphicsSettings)
 	CheckBox *disableCulling = graphicsSettings->Add(new CheckBox(&g_Config.bDisableRangeCulling, gr->T("Disable culling")));
 	disableCulling->SetDisabledPtr(&g_Config.bSoftwareRendering);
 
-	static const char *skipGpuReadbackModes[] = { "No (default)", "Skip", "Copy to texture" };
+	static const char *skipGpuReadbackModes[] = { "No (default)", "Skip", "Copy to texture" , "Half skip"};
 
 	PopupMultiChoice *skipGPUReadbacks = graphicsSettings->Add(new PopupMultiChoice(&g_Config.iSkipGPUReadbackMode, gr->T("Skip GPU Readbacks"), skipGpuReadbackModes, 0, ARRAY_SIZE(skipGpuReadbackModes), I18NCat::GRAPHICS, screenManager()));
 	skipGPUReadbacks->SetDisabledPtr(&g_Config.bSoftwareRendering);