Fix vulkan image sampling

src/gpu/vk/GrVkSampler.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "GrVkSampler.h"
 
 #include "GrTextureAccess.h"
 #include "GrVkGpu.h"
 
 static inline VkSamplerAddressMode tile_to_vk_sampler_address(SkShader::TileMode tm) {
     static const VkSamplerAddressMode gWrapModes[] = {
         VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE,
         VK_SAMPLER_ADDRESS_MODE_REPEAT,
         VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT
     };
     GR_STATIC_ASSERT(SkShader::kTileModeCount == SK_ARRAY_COUNT(gWrapModes));
     GR_STATIC_ASSERT(0 == SkShader::kClamp_TileMode);
     GR_STATIC_ASSERT(1 == SkShader::kRepeat_TileMode);
     GR_STATIC_ASSERT(2 == SkShader::kMirror_TileMode);
     return gWrapModes[tm];
 }
 
 GrVkSampler* GrVkSampler::Create(const GrVkGpu* gpu, const GrTextureParams& params,
                                  uint32_t mipLevels) {
-
     static VkFilter vkMinFilterModes[] = {
         VK_FILTER_NEAREST,
         VK_FILTER_LINEAR,
         VK_FILTER_LINEAR
     };
     static VkFilter vkMagFilterModes[] = {
         VK_FILTER_NEAREST,
         VK_FILTER_LINEAR,
         VK_FILTER_LINEAR
     };
@@ skipping 13 matching lines @@
     createInfo.anisotropyEnable = VK_FALSE;
     createInfo.maxAnisotropy = 1.0f;
     createInfo.compareEnable = VK_FALSE;
     createInfo.compareOp = VK_COMPARE_OP_NEVER;
     // Vulkan doesn't have a direct mapping of GL's nearest or linear filters for minFilter since
     // there is always a mipmapMode. To get the same effect as GL we can set minLod = maxLod = 0.0.
     // This works since our min and mag filters are the same (this forces us to use mag on the 0
     // level mip). If the filters weren't the same we could set min = 0 and max = 0.25 to force
     // the minFilter on mip level 0.
     createInfo.minLod = 0.0f;
-    createInfo.maxLod = (mipLevels == 1) ? 0.0f : (float)(mipLevels);
+    bool useMipMaps = GrTextureParams::kMipMap_FilterMode == params.filterMode() && mipLevels > 1;
+    createInfo.maxLod = !useMipMaps ? 0.0f : (float)(mipLevels);
     createInfo.borderColor = VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK;
     createInfo.unnormalizedCoordinates = VK_FALSE;
 
     VkSampler sampler;
     GR_VK_CALL_ERRCHECK(gpu->vkInterface(), CreateSampler(gpu->device(),
                                                           &createInfo,
                                                           nullptr,
                                                           &sampler));
 
     return new GrVkSampler(sampler, GenerateKey(params, mipLevels));
@@ skipping 15 matching lines @@
     key |= (params.getTileModeX() << kTileModeXShift);
 
     GR_STATIC_ASSERT(SkShader::kTileModeCount <= 4);
     key |= (params.getTileModeY() << kTileModeYShift);
 
     SkASSERT(mipLevels < 1024);
     key |= (mipLevels << kMipLevelShift);
 
     return key;
 }