Make the frame-time budget for uploading replacement textures take framerate into account

Core/HW/Display.cpp

@@ -105,9 +105,15 @@ static void CalculateFPS() {
 
 // TODO: Also average actualFps
 void __DisplayGetFPS(float *out_vps, float *out_fps, float *out_actual_fps) {
-	*out_vps = (float)fps;
-	*out_fps = flips;
-	*out_actual_fps = actualFps;
+	if (out_vps) {
+		*out_vps = (float)fps;
+	}
+	if (out_fps) {
+		*out_fps = flips;
+	}
+	if (out_actual_fps) {
+		*out_actual_fps = actualFps;
+	}
 }
 
 void __DisplayGetVPS(float *out_vps) {

GPU/Common/ReplacedTexture.cpp

@@ -176,7 +176,7 @@ bool ReplacedTexture::Poll(double budget) {
 	lastUsed_ = now;
 
 	// Let's not even start a new texture if we're already behind.
-	if (budget < 0.0)
+	if (budget <= 0.0)
 		return false;
 
 	_assert_(!threadWaitable_);

GPU/Common/TextureCacheCommon.cpp

@@ -34,6 +34,7 @@
 #include "Core/Config.h"
 #include "Core/Debugger/MemBlockInfo.h"
 #include "Core/System.h"
+#include "Core/HW/Display.h"
 #include "GPU/Common/FramebufferManagerCommon.h"
 #include "GPU/Common/TextureCacheCommon.h"
 #include "GPU/Common/TextureDecoder.h"
@@ -127,6 +128,14 @@ void TextureCacheCommon::StartFrame() {
 	timesInvalidatedAllThisFrame_ = 0;
 	replacementTimeThisFrame_ = 0.0;
 
+	float fps;
+	__DisplayGetFPS(nullptr, &fps, nullptr);
+	if (fps <= 5.0f) {
+		fps = 60.0f;
+	}
+	// Allow spending half a frame on uploading textures.
+	replacementFrameBudgetSeconds_ = 0.5f / fps;
+
 	if ((DebugOverlay)g_Config.iDebugOverlay == DebugOverlay::DEBUG_STATS) {
 		gpuStats.numReplacerTrackedTex = replacer_.GetNumTrackedTextures();
 		gpuStats.numCachedReplacedTextures = replacer_.GetNumCachedReplacedTextures();
@@ -530,7 +539,7 @@ TexCacheEntry *TextureCacheCommon::SetTexture() {
 			}
 		}
 
-		if (match && (entry->status & TexCacheEntry::STATUS_TO_REPLACE) && replacementTimeThisFrame_ < replacementFrameBudget_) {
+		if (match && (entry->status & TexCacheEntry::STATUS_TO_REPLACE) && replacementTimeThisFrame_ < replacementFrameBudgetSeconds_) {
 			int w0 = gstate.getTextureWidth(0);
 			int h0 = gstate.getTextureHeight(0);
 			int d0 = 1;
@@ -1572,10 +1581,9 @@ ReplacedTexture *TextureCacheCommon::FindReplacement(TexCacheEntry *entry, int *
 }
 
 void TextureCacheCommon::PollReplacement(TexCacheEntry *entry, int *w, int *h, int *d) {
-	// Allow some delay to reduce pop-in.
-	constexpr double MAX_BUDGET_PER_TEX = 0.25 / 60.0;
-
-	double budget = std::min(MAX_BUDGET_PER_TEX, replacementFrameBudget_ - replacementTimeThisFrame_);
+	double budget = replacementFrameBudgetSeconds_ - replacementTimeThisFrame_;
+	// Note: Don't avoid the Poll call if budget is 0, we do meaningful things there.
+	// Poll also handles negative budgets.
 
 	double replaceStart = time_now_d();
 	if (entry->replacedTexture->Poll(budget)) {
@@ -3157,7 +3165,7 @@ void TextureCacheCommon::DrawImGuiDebug(uint64_t &selectedTextureId) const {
 		ImGui::Text("Texels scaled this frame: %d", texelsScaledThisFrame_);
 		ImGui::Text("Low memory mode: %d", (int)lowMemoryMode_);
 		if (ImGui::CollapsingHeader("Texture Replacement", ImGuiTreeNodeFlags_DefaultOpen)) {
-			ImGui::Text("Frame time/budget: %0.3f/%0.3f ms", replacementTimeThisFrame_ * 1000.0f, replacementFrameBudget_ * 1000.0f);
+			ImGui::Text("Frame time/budget: %0.3f/%0.3f ms", replacementTimeThisFrame_ * 1000.0f, replacementFrameBudgetSeconds_ * 1000.0f);
 			ImGui::Text("UNLOADED: %d PENDING: %d NOT_FOUND: %d ACTIVE: %d CANCEL_INIT: %d",
 				replacementStateCounts[(int)ReplacementState::UNLOADED],
 				replacementStateCounts[(int)ReplacementState::PENDING],

GPU/Common/TextureCacheCommon.h

@@ -496,8 +496,8 @@ protected:
 	int texelsScaledThisFrame_ = 0;
 	int timesInvalidatedAllThisFrame_ = 0;
 	double replacementTimeThisFrame_ = 0;
-	// TODO: Maybe vary by FPS...
-	double replacementFrameBudget_ = 0.5 / 60.0;
+	// Recomputed once per frame. Depends FPS and soon also config.
+	double replacementFrameBudgetSeconds_ = 0.5 / 60.0;
 
 	TexCache cache_;
 	u32 cacheSizeEstimate_ = 0;

UI/EmuScreen.cpp

@@ -1768,8 +1768,6 @@ void EmuScreen::runImDebugger() {
 	if (g_Config.bShowImDebugger) {
 		Draw::DrawContext *draw = screenManager()->getDrawContext();
 		if (!imguiInited_) {
-			imguiInited_ = true;
-
 			// TODO: Do this only on demand.
 			IMGUI_CHECKVERSION();
 			ctx_ = ImGui::CreateContext();
@@ -1783,6 +1781,7 @@ void EmuScreen::runImDebugger() {
 			// This call works even if fontData is nullptr, in which case the font just won't get loaded.
 			// This takes ownership of the font array.
 			ImGui_ImplThin3d_Init(draw, fontData, size);
+			imguiInited_ = true;
 		}
 
 		if (PSP_IsInited()) {