Added check and warning about non-power-of-2 textures

src/graphics/opengl/gldevice.cpp

@@ -417,12 +417,16 @@ bool CGLDevice::GetLightEnabled(int index)
 Texture CGLDevice::CreateTexture(CImage *image, const TextureCreateParams &params)
 {
     ImageData *data = image->GetData();
-    if (data == NULL)
+    if (data == nullptr)
     {
         GetLogger()->Error("Invalid texture data\n");
         return Texture(); // invalid texture
     }
 
+    Math::IntPoint size = image->GetSize();
+    if (!Math::IsPowerOfTwo(size.x) || !Math::IsPowerOfTwo(size.y))
+        GetLogger()->Warn("Creating non-power-of-2 texture (%dx%d)!\n", size.x, size.y);
+
     return CreateTexture(data, params);
 }
 

src/math/func.h

@@ -128,6 +128,12 @@ inline float Rand()
     return static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
 }
 
+//! Returns whether \a x is an even power of 2
+inline bool IsPowerOfTwo(unsigned int x)
+{
+   return x && !(x & (x - 1));
+}
+
 //! Returns the next nearest power of two to \a x
 inline int NextPowerOfTwo(int x)
 {

test/unit/CMakeLists.txt

@@ -177,6 +177,7 @@ set(UT_SOURCES
 main.cpp
 app/app_test.cpp
 graphics/engine/lightman_test.cpp
+math/func_test.cpp
 math/geometry_test.cpp
 math/matrix_test.cpp
 math/vector_test.cpp

test/unit/math/func_test.cpp

@@ -0,0 +1,55 @@
+// * This file is part of the COLOBOT source code
+// * Copyright (C) 2012, Polish Portal of Colobot (PPC)
+// *
+// * This program is free software: you can redistribute it and/or modify
+// * it under the terms of the GNU General Public License as published by
+// * the Free Software Foundation, either version 3 of the License, or
+// * (at your option) any later version.
+// *
+// * This program is distributed in the hope that it will be useful,
+// * but WITHOUT ANY WARRANTY; without even the implied warranty of
+// * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// * GNU General Public License for more details.
+// *
+// * You should have received a copy of the GNU General Public License
+// * along with this program. If not, see  http://www.gnu.org/licenses/.
+
+/*
+  Unit tests for math functions.
+ */
+
+#include "math/func.h"
+
+#include "gtest/gtest.h"
+
+
+TEST(IsPowerOfTwo, TestDifferentValues)
+{
+    EXPECT_FALSE(Math::IsPowerOfTwo(0));
+    EXPECT_TRUE(Math::IsPowerOfTwo(1));
+    EXPECT_TRUE(Math::IsPowerOfTwo(2));
+    EXPECT_FALSE(Math::IsPowerOfTwo(3));
+    EXPECT_TRUE(Math::IsPowerOfTwo(4));
+
+    EXPECT_FALSE(Math::IsPowerOfTwo(31));
+    EXPECT_TRUE(Math::IsPowerOfTwo(32));
+    EXPECT_FALSE(Math::IsPowerOfTwo(33));
+
+    EXPECT_FALSE(Math::IsPowerOfTwo(1234));
+}
+
+TEST(NextPowerOfTwo, TestDifferentValues)
+{
+    EXPECT_EQ(2, Math::NextPowerOfTwo(2));
+    EXPECT_EQ(4, Math::NextPowerOfTwo(3));
+    EXPECT_EQ(4, Math::NextPowerOfTwo(4));
+    EXPECT_EQ(8, Math::NextPowerOfTwo(5));
+
+    EXPECT_EQ(8, Math::NextPowerOfTwo(7));
+    EXPECT_EQ(8, Math::NextPowerOfTwo(8));
+    EXPECT_EQ(16, Math::NextPowerOfTwo(9));
+
+    EXPECT_EQ(32, Math::NextPowerOfTwo(31));
+    EXPECT_EQ(32, Math::NextPowerOfTwo(32));
+    EXPECT_EQ(64, Math::NextPowerOfTwo(33));
+}