measure fps

demos/demo1-wireframes/src/wirescene.cpp

@@ -4,6 +4,7 @@
 
 #include <libgba-sprite-engine/gba/tonc_memdef.h>
 #include <libgba-sprite-engine/gba_engine.h>
+#include <libgba-sprite-engine/background/text_stream.h>
 #include "wirescene.h"
 
 
@@ -19,6 +20,7 @@ Camera WireScene::camera() {
     return Camera(VectorFx::fromInt(0, 0, 10), VectorFx::fromInt(0, 0, 0));
 }
 
+int msecs = 1;
 void WireScene::load() {
     foregroundPalette = std::unique_ptr<ForegroundPaletteManager>(new ForegroundPaletteManager());
     backgroundPalette = std::unique_ptr<BackgroundPaletteManager>(new BackgroundPaletteManager(pal, sizeof(pal)));
@@ -46,9 +48,17 @@ void WireScene::load() {
     cube->addFace({ 0, 4, 7});
     cube->addFace({ 4, 5, 6});
     cube->addFace({ 4, 6, 7});
+
+    engine->getTimer()->start();
 }
 
 void WireScene::tick(u16 keys) {
+    int curmsecs = engine->getTimer()->getMsecs();
+    int elapsed = curmsecs - msecs;
+    msecs = curmsecs;
+
+    TextStream::instance().setText(std::to_string(1000 / elapsed) + std::string(" FPS"), 1, 1);
+
     cube->rotate(2, 2);
 
     if(keys & KEY_A) {

engine/include/libgba-sprite-engine/timer.h

@@ -31,10 +31,10 @@ public:
     std::string to_string();
 
     int getTotalMsecs();
-    int getMsecs() { return msecs; }
-    int getSecs() { return secs; }
-    int getMinutes() { return minutes; }
-    int getHours() { return hours; }
+    inline int getMsecs() { return msecs; }
+    inline int getSecs() { return secs; }
+    inline int getMinutes() { return minutes; }
+    inline int getHours() { return hours; }
 
     friend std::ostream& operator<<(std::ostream& os, Timer& timer);
 };

engine/src/gba_engine.cpp

@@ -130,12 +130,11 @@ void GBAEngine::update() {
     // WARNING - keep amount of instructions as minimal as possible in here!
 
     u16 keys = readKeys();
-    // main scene update loop call. This *might* take a while.
-    currentScene->tick(keys);
 
     // TODO use software interrupt Vsyncing instead of 2 wasteful whiles
     vsync();
     renderClear();
+    currentScene->tick(keys);
     render();
     flipPage();
 }