diff --git a/sphericalenvmapping/sphericalenvmapping.cpp b/sphericalenvmapping/sphericalenvmapping.cpp
index 5bd01198..7422063a 100644
--- a/sphericalenvmapping/sphericalenvmapping.cpp
+++ b/sphericalenvmapping/sphericalenvmapping.cpp
@@ -127,30 +127,19 @@ public:
 		renderPassBeginInfo.clearValueCount = 2;
 		renderPassBeginInfo.pClearValues = clearValues;
 
-		VkResult err;
-
 		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
 		{
 			// Set target frame buffer
 			renderPassBeginInfo.framebuffer = frameBuffers[i];
 
-			err = vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo);
-			assert(!err);
+			VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));
 
 			vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
 
-			VkViewport viewport = vkTools::initializers::viewport(
-				(float)width,
-				(float)height,
-				0.0f,
-				1.0f);
+			VkViewport viewport = vkTools::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
 			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
 
-			VkRect2D scissor = vkTools::initializers::rect2D(
-				width,
-				height,
-				0,
-				0);
+			VkRect2D scissor = vkTools::initializers::rect2D(width, height,	0, 0);
 			vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
 
 			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, NULL);
@@ -164,18 +153,14 @@ public:
 
 			vkCmdEndRenderPass(drawCmdBuffers[i]);
 
-			err = vkEndCommandBuffer(drawCmdBuffers[i]);
-			assert(!err);
+			VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
 		}
 	}
 
 	void draw()
 	{
-		VkResult err;
-
 		// Get next image in the swap chain (back/front buffer)
-		err = swapChain.acquireNextImage(semaphores.presentComplete, &currentBuffer);
-		assert(!err);
+		VK_CHECK_RESULT(swapChain.acquireNextImage(semaphores.presentComplete, &currentBuffer));
 
 		submitPostPresentBarrier(swapChain.buffers[currentBuffer].image);
 
@@ -184,16 +169,13 @@ public:
 		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];
 
 		// Submit to queue
-		err = vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE);
-		assert(!err);
+		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
 
 		submitPrePresentBarrier(swapChain.buffers[currentBuffer].image);
 
-		err = swapChain.queuePresent(queue, currentBuffer, semaphores.renderComplete);
-		assert(!err);
+		VK_CHECK_RESULT(swapChain.queuePresent(queue, currentBuffer, semaphores.renderComplete));
 
-		err = vkQueueWaitIdle(queue);
-		assert(!err);
+		VK_CHECK_RESULT(vkQueueWaitIdle(queue));
 	}
 
 	void loadMeshes()
@@ -265,8 +247,7 @@ public:
 				poolSizes.data(),
 				2);
 
-		VkResult vkRes = vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool);
-		assert(!vkRes);
+		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));
 	}
 
 	void setupDescriptorSetLayout()
@@ -290,16 +271,14 @@ public:
 				setLayoutBindings.data(),
 				setLayoutBindings.size());
 
-		VkResult err = vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout);
-		assert(!err);
+		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout));
 
 		VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo =
 			vkTools::initializers::pipelineLayoutCreateInfo(
 				&descriptorSetLayout,
 				1);
 
-		err = vkCreatePipelineLayout(device, &pPipelineLayoutCreateInfo, nullptr, &pipelineLayout);
-		assert(!err);
+		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pPipelineLayoutCreateInfo, nullptr, &pipelineLayout));
 	}
 
 	void setupDescriptorSet()
@@ -310,8 +289,7 @@ public:
 				&descriptorSetLayout,
 				1);
 
-		VkResult vkRes = vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet);
-		assert(!vkRes);
+		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));
 
 		// Color map image descriptor
 		VkDescriptorImageInfo texDescriptorColorMap =
@@ -411,8 +389,7 @@ public:
 		pipelineCreateInfo.stageCount = shaderStages.size();
 		pipelineCreateInfo.pStages = shaderStages.data();
 
-		VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.sem);
-		assert(!err);
+		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.sem));
 	}
 
 	void prepareUniformBuffers()
@@ -447,8 +424,7 @@ public:
 		uboVS.normal = glm::inverseTranspose(uboVS.view * uboVS.model);
 
 		uint8_t *pData;
-		VkResult err = vkMapMemory(device, uniformData.vertexShader.memory, 0, sizeof(uboVS), 0, (void **)&pData);
-		assert(!err);
+		VK_CHECK_RESULT(vkMapMemory(device, uniformData.vertexShader.memory, 0, sizeof(uboVS), 0, (void **)&pData));
 		memcpy(pData, &uboVS, sizeof(uboVS));
 		vkUnmapMemory(device, uniformData.vertexShader.memory);
 	}
@@ -488,9 +464,11 @@ public:
 		{
 		case 0x6B:
 		case 0x20:
+		case GAMEPAD_BUTTON_A:
 			changeMatCapIndex(1);
 			break;
 		case 0x6D:
+		case GAMEPAD_BUTTON_X:
 			changeMatCapIndex(-1);
 			break;
 		}