Fix some MSVC warnings

CMakeLists.txt

@@ -860,7 +860,7 @@ add_executable (pbrt::pspec ALIAS pspec)
 target_compile_definitions (pspec PRIVATE ${PBRT_DEFINITIONS})
 target_compile_options (pspec PRIVATE ${PBRT_CXX_FLAGS})
 target_include_directories (pspec PRIVATE src src/ext)
-target_link_libraries (pspec PRIVATE ${ALL_PBRT_LIBS})
+target_link_libraries (pspec PRIVATE ${ALL_PBRT_LIBS} pbrt_warnings)
 
 add_sanitizers (pspec)
 

src/pbrt/samplers_test.cpp

@@ -76,7 +76,7 @@ static void checkElementary(const char *name, std::vector<Point2f> samples,
         // in each dimension.
         int nx = 1 << i, ny = 1 << (logSamples - i);
 
-        std::vector<int> count(1 << logSamples, 0);
+        std::vector<int> count(size_t(1 << logSamples), 0);
         for (const Point2f &s : samples) {
             // Map the sample to an interval
             Float x = nx * s.x, y = ny * s.y;

src/pbrt/util/lowdiscrepancy.h

@@ -240,7 +240,7 @@ struct OwenScrambler {
         for (int b = 1; b < 32; ++b) {
             // Apply Owen scrambling to binary digit _b_ in _v_
             uint32_t mask = (~0u) << (32 - b);
-            if (MixBits((v & mask) ^ seed) & (1u << b))
+            if ((uint32_t)MixBits((v & mask) ^ seed) & (1u << b))
                 v ^= 1u << (31 - b);
         }
         return v;

src/pbrt/util/math.h

@@ -243,9 +243,9 @@ PBRT_CPU_GPU inline Float Lerp(Float x, Float a, Float b) {
 template <typename T, typename U, typename V>
 PBRT_CPU_GPU inline constexpr T Clamp(T val, U low, V high) {
     if (val < low)
-        return low;
+        return T(low);
     else if (val > high)
-        return high;
+        return T(high);
     else
         return val;
 }

src/pbrt/util/progressreporter.h

@@ -71,7 +71,7 @@ class ProgressReporter {
 
 #ifdef PBRT_BUILD_GPU_RENDERER
     std::vector<cudaEvent_t> gpuEvents;
-    std::atomic<int> gpuEventsLaunchedOffset;
+    std::atomic<size_t> gpuEventsLaunchedOffset;
     int gpuEventsFinishedOffset;
 #endif
 };