Modify GPU timer API;

- lovr.graphics.tock returns the latest value of the timer, or 0.
- Timers are not in the stats table anymore.

This is to prepare for an upcoming internal change that affects timers.

src/api/l_graphics.c

@@ -412,8 +412,8 @@ static int l_lovrGraphicsTick(lua_State* L) {
 static int l_lovrGraphicsTock(lua_State* L) {
   lovrGraphicsFlush();
   const char* label = luaL_checkstring(L, 1);
-  lovrGraphicsTock(label);
-  return 0;
+  lua_pushnumber(L, lovrGraphicsTock(label));
+  return 1;
 }
 
 static int l_lovrGraphicsGetFeatures(lua_State* L) {
@@ -464,13 +464,6 @@ static int l_lovrGraphicsGetStats(lua_State* L) {
   lua_setfield(L, 1, "drawcalls");
   lua_pushinteger(L, stats->shaderSwitches);
   lua_setfield(L, 1, "shaderswitches");
-  lua_createtable(L, 0, (int) stats->timers.length);
-  for (size_t i = 0; i < stats->timers.length; i++) {
-    lua_pushstring(L, stats->timers.data[i].label);
-    lua_pushnumber(L, stats->timers.data[i].time);
-    lua_settable(L, -3);
-  }
-  lua_setfield(L, 1, "timers");
   return 1;
 }
 

src/modules/graphics/graphics.h

@@ -1,6 +1,5 @@
 #include "graphics/font.h"
 #include "data/modelData.h"
-#include "core/arr.h"
 #include "core/maf.h"
 #include "util.h"
 #include "platform.h"
@@ -195,15 +194,9 @@ typedef struct {
   int blockAlign;
 } GpuLimits;
 
-typedef struct {
-  const char* label;
-  double time;
-} GpuTimer;
-
 typedef struct {
   int shaderSwitches;
   int drawCalls;
-  arr_t(GpuTimer) timers;
 } GpuStats;
 
 typedef struct {
@@ -227,7 +220,7 @@ void lovrGpuStencil(StencilAction action, int replaceValue, StencilCallback call
 void lovrGpuPresent(void);
 void lovrGpuDirtyTexture(void);
 void lovrGpuTick(const char* label);
-void lovrGpuTock(const char* label);
+double lovrGpuTock(const char* label);
 const GpuFeatures* lovrGpuGetFeatures(void);
 const GpuLimits* lovrGpuGetLimits(void);
 const GpuStats* lovrGpuGetStats(void);

src/modules/graphics/opengl.c

@@ -1091,8 +1091,6 @@ void lovrGpuInit(getProcAddressProc getProcAddress) {
     arr_init(&state.incoherents[i]);
   }
 
-  arr_init(&state.stats.timers);
-
   TextureData* textureData = lovrTextureDataCreate(1, 1, 0xff, FORMAT_RGBA);
   state.defaultTexture = lovrTextureCreate(TEXTURE_2D, &textureData, 1, true, false, 0);
   lovrTextureSetFilter(state.defaultTexture, (TextureFilter) { .mode = FILTER_NEAREST });
@@ -1111,7 +1109,6 @@ void lovrGpuDestroy() {
   for (int i = 0; i < MAX_BARRIERS; i++) {
     arr_free(&state.incoherents[i]);
   }
-  arr_free(&state.stats.timers);
   memset(&state, 0, sizeof(state));
 }
 
@@ -1222,8 +1219,7 @@ void lovrGpuDraw(DrawCommand* draw) {
 }
 
 void lovrGpuPresent() {
-  state.stats.drawCalls = state.stats.shaderSwitches = 0;
-  arr_clear(&state.stats.timers);
+  memset(&state.stats, 0, sizeof(state.stats));
 }
 
 void lovrGpuStencil(StencilAction action, int replaceValue, StencilCallback callback, void* userdata) {
@@ -1282,10 +1278,10 @@ void lovrGpuTick(const char* label) {
 #endif
 }
 
-void lovrGpuTock(const char* label) {
+double lovrGpuTock(const char* label) {
 #ifndef LOVR_WEBGL
   TimerList* timer = map_get(&state.timers, label);
-  if (!timer) return;
+  if (!timer) return 0.;
 
   glEndQuery(GL_TIME_ELAPSED);
 
@@ -1297,9 +1293,10 @@ void lovrGpuTock(const char* label) {
     }
 
     glGetQueryObjectui64v(timer->timers[timer->oldest], GL_QUERY_RESULT, &timer->ns);
-    arr_push(&state.stats.timers, ((GpuTimer) { .label = label, .time = timer->ns / 1e9 }));
     timer->oldest = (timer->oldest + 1) % 4;
   }
+
+  return timer->ns / 1e9;
 #endif
 }