Add ktx

2026-06-14 19:09:18 +01:00
parent 14bd1a9271
commit 13fa90a0e9
3958 changed files with 999286 additions and 4 deletions
@@ -0,0 +1,66 @@
+/* -*- tab-width: 4; -*- */
+/* vi: set sw=2 ts=4 expandtab: */
+
+/*
+ * Copyright 2017-2020 Mark Callow.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <ktx.h>
+#include <vulkan/vulkan.hpp>
+
+#include "VulkanContext.h"
+
+class TextureTranscoder {
+  public:
+    TextureTranscoder(VulkanContext& vkctx) {
+        vkctx.gpu.getFeatures(&deviceFeatures);
+
+        if (deviceFeatures.textureCompressionASTC_LDR)
+            defaultTf = KTX_TTF_ASTC_4x4_RGBA;
+        else if (deviceFeatures.textureCompressionETC2)
+            defaultTf = KTX_TTF_ETC;
+        else if (deviceFeatures.textureCompressionBC)
+            defaultTf = KTX_TTF_BC1_OR_3;
+        else if (vkctx.enabledDeviceExtensions.pvrtc) {
+            defaultTf = KTX_TTF_PVRTC2_4_RGBA;
+        } else {
+            std::stringstream message;
+
+            message << "Vulkan implementation does not support any available transcode target.";
+            throw std::runtime_error(message.str());
+        }
+    }
+
+    void transcode(ktxTexture2* kTexture) {
+        KTX_error_code ktxresult;
+        ktx_transcode_fmt_e tf;
+        khr_df_model_e colorModel = ktxTexture2_GetColorModel_e(kTexture);
+
+        if (colorModel == KHR_DF_MODEL_UASTC
+            && deviceFeatures.textureCompressionASTC_LDR) {
+            tf = KTX_TTF_ASTC_4x4_RGBA;
+        } else if (colorModel == KHR_DF_MODEL_ETC1S
+                   && deviceFeatures.textureCompressionETC2) {
+            tf = KTX_TTF_ETC;
+        } else {
+            tf = defaultTf;
+        }
+
+        ktxresult = ktxTexture2_TranscodeBasis(kTexture, tf, 0);
+        if (KTX_SUCCESS != ktxresult) {
+            std::stringstream message;
+
+            message << "Transcoding of ktxTexture2 to "
+                    << ktxTranscodeFormatString(tf) << " failed: "
+                    << ktxErrorString(ktxresult);
+            throw std::runtime_error(message.str());
+        }
+    }
+
+  protected:
+    ktx_transcode_fmt_e defaultTf;
+    vk::PhysicalDeviceFeatures deviceFeatures;
+};