diff --git a/distrho/DistrhoUtils.hpp b/distrho/DistrhoUtils.hpp
index d2d2e836..b1391efa 100644
--- a/distrho/DistrhoUtils.hpp
+++ b/distrho/DistrhoUtils.hpp
@@ -24,6 +24,9 @@
 #include <cstdlib>
 #include <cstring>
 
+#include <cmath>
+#include <limits>
+
 #ifdef DISTRHO_PROPER_CPP11_SUPPORT
 # include <cstdint>
 #else
@@ -46,18 +49,28 @@ inline float round(float __x)
 // -----------------------------------------------------------------------
 // misc functions
 
+/*
+ * Return a 64-bit number from 4 8-bit numbers.
+ */
 static inline
-int64_t d_cconst(const int a, const int b, const int c, const int d) noexcept
+int64_t d_cconst(const uint8_t a, const uint8_t b, const uint8_t c, const uint8_t d) noexcept
 {
     return (a << 24) | (b << 16) | (c << 8) | (d << 0);
 }
 
+/*
+ * Dummy function.
+ */
 static inline
 void d_pass() noexcept {}
 
 // -----------------------------------------------------------------------
 // string print functions
 
+/*
+ * Print a string to stdout with newline (gray color).
+ * Does nothing if DEBUG is not defined.
+ */
 #ifndef DEBUG
 # define d_debug(...)
 #else
@@ -75,6 +88,9 @@ void d_debug(const char* const fmt, ...) noexcept
 }
 #endif
 
+/*
+ * Print a string to stdout with newline.
+ */
 static inline
 void d_stdout(const char* const fmt, ...) noexcept
 {
@@ -87,6 +103,9 @@ void d_stdout(const char* const fmt, ...) noexcept
     } catch (...) {}
 }
 
+/*
+ * Print a string to stderr with newline.
+ */
 static inline
 void d_stderr(const char* const fmt, ...) noexcept
 {
@@ -99,6 +118,9 @@ void d_stderr(const char* const fmt, ...) noexcept
     } catch (...) {}
 }
 
+/*
+ * Print a string to stderr with newline (red color).
+ */
 static inline
 void d_stderr2(const char* const fmt, ...) noexcept
 {
@@ -112,18 +134,69 @@ void d_stderr2(const char* const fmt, ...) noexcept
     } catch (...) {}
 }
 
+/*
+ * Print a safe assertion error message.
+ */
 static inline
 void d_safe_assert(const char* const assertion, const char* const file, const int line) noexcept
 {
     d_stderr2("assertion failure: \"%s\" in file %s, line %i", assertion, file, line);
 }
 
+/*
+ * Print a safe exception error message.
+ */
 static inline
 void d_safe_exception(const char* const exception, const char* const file, const int line) noexcept
 {
     d_stderr2("exception caught: \"%s\" in file %s, line %i", exception, file, line);
 }
 
+// -----------------------------------------------------------------------
+// math functions
+
+/*
+ * Safely compare two floating point numbers.
+ * Returns true if they match.
+ */
+template<typename T>
+static inline
+bool d_isEqual(const T& v1, const T& v2)
+{
+    return std::abs(v1-v2) < std::numeric_limits<T>::epsilon();
+}
+
+/*
+ * Safely compare two floating point numbers.
+ * Returns true if they don't match.
+ */
+template<typename T>
+static inline
+bool d_isNotEqual(const T& v1, const T& v2)
+{
+    return std::abs(v1-v2) >= std::numeric_limits<T>::epsilon();
+}
+
+/*
+ * Safely check if a floating point number is zero.
+ */
+template<typename T>
+static inline
+bool d_isZero(const T& value)
+{
+    return std::abs(value) < std::numeric_limits<T>::epsilon();
+}
+
+/*
+ * Safely check if a floating point number is not zero.
+ */
+template<typename T>
+static inline
+bool d_isNotZero(const T& value)
+{
+    return std::abs(value) >= std::numeric_limits<T>::epsilon();
+}
+
 // -----------------------------------------------------------------------
 
 #endif // DISTRHO_UTILS_HPP_INCLUDED
diff --git a/distrho/src/DistrhoPluginInternal.hpp b/distrho/src/DistrhoPluginInternal.hpp
index 7b4c04bd..e9e2e23c 100644
--- a/distrho/src/DistrhoPluginInternal.hpp
+++ b/distrho/src/DistrhoPluginInternal.hpp
@@ -83,7 +83,7 @@ struct Plugin::PrivateData {
           sampleRate(d_lastSampleRate)
     {
         DISTRHO_SAFE_ASSERT(bufferSize != 0);
-        DISTRHO_SAFE_ASSERT(sampleRate != 0.0);
+        DISTRHO_SAFE_ASSERT(d_isNotZero(sampleRate));
     }
 
     ~PrivateData() noexcept
@@ -433,7 +433,7 @@ public:
         DISTRHO_SAFE_ASSERT_RETURN(fPlugin != nullptr,);
         DISTRHO_SAFE_ASSERT(sampleRate > 0.0);
 
-        if (fData->sampleRate == sampleRate)
+        if (d_isEqual(fData->sampleRate, sampleRate))
             return;
 
         fData->sampleRate = sampleRate;
diff --git a/distrho/src/DistrhoUI.cpp b/distrho/src/DistrhoUI.cpp
index fa5c4499..82ea7a56 100644
--- a/distrho/src/DistrhoUI.cpp
+++ b/distrho/src/DistrhoUI.cpp
@@ -96,8 +96,8 @@ void UI::d_uiReshape(uint width, uint height)
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
-    glOrtho(0, width, height, 0, 0.0f, 1.0f);
-    glViewport(0, 0, width, height);
+    glOrtho(0.0, static_cast<GLdouble>(width), static_cast<GLdouble>(height), 0.0, 0.0, 1.0);
+    glViewport(0, 0, static_cast<GLsizei>(width), static_cast<GLsizei>(height));
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
 }
diff --git a/distrho/src/DistrhoUIInternal.hpp b/distrho/src/DistrhoUIInternal.hpp
index b5ddd0d1..a17e2aae 100644
--- a/distrho/src/DistrhoUIInternal.hpp
+++ b/distrho/src/DistrhoUIInternal.hpp
@@ -75,7 +75,7 @@ struct UI::PrivateData {
           setSizeCallbackFunc(nullptr),
           ptr(nullptr)
     {
-        DISTRHO_SAFE_ASSERT(sampleRate != 0.0);
+        DISTRHO_SAFE_ASSERT(d_isNotZero(sampleRate));
 
 #if defined(DISTRHO_PLUGIN_TARGET_DSSI) || defined(DISTRHO_PLUGIN_TARGET_LV2)
         parameterOffset += DISTRHO_PLUGIN_NUM_INPUTS + DISTRHO_PLUGIN_NUM_OUTPUTS;
@@ -331,7 +331,7 @@ public:
         glWindow.setTitle(uiTitle);
     }
 
-    void setWindowTransientWinId(const intptr_t winId)
+    void setWindowTransientWinId(const uintptr_t winId)
     {
         glWindow.setTransientWinId(winId);
     }
@@ -351,7 +351,7 @@ public:
         DISTRHO_SAFE_ASSERT_RETURN(fUI != nullptr,);
         DISTRHO_SAFE_ASSERT(sampleRate > 0.0);
 
-        if (fData->sampleRate == sampleRate)
+        if (d_isEqual(fData->sampleRate, sampleRate))
             return;
 
         fData->sampleRate = sampleRate;