From 0429ec8053550c8f7a1994532777d5646a48dadb Mon Sep 17 00:00:00 2001
From: Xaver Hugl <xaver.hugl@gmail.com>
Date: Thu, 12 Oct 2023 15:23:07 +0200
Subject: [PATCH] libkwineffects: add a 3d lookup table class

---
 src/CMakeLists.txt             |  2 +
 src/libkwineffects/gllut3D.cpp | 88 ++++++++++++++++++++++++++++++++++
 src/libkwineffects/gllut3D.h   | 44 +++++++++++++++++
 3 files changed, 134 insertions(+)
 create mode 100644 src/libkwineffects/gllut3D.cpp
 create mode 100644 src/libkwineffects/gllut3D.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8df1e0a5d7..84f61445de 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -110,6 +110,7 @@ target_sources(kwin PRIVATE
     libkwineffects/effecttogglablestate.cpp
     libkwineffects/glframebuffer.cpp
     libkwineffects/gllut.cpp
+    libkwineffects/gllut3D.cpp
     libkwineffects/glplatform.cpp
     libkwineffects/glshader.cpp
     libkwineffects/glshadermanager.cpp
@@ -432,6 +433,7 @@ install(FILES
     libkwineffects/colorspace.h
     libkwineffects/glframebuffer.h
     libkwineffects/gllut.h
+    libkwineffects/gllut3D.h
     libkwineffects/glplatform.h
     libkwineffects/glshader.h
     libkwineffects/glshadermanager.h
diff --git a/src/libkwineffects/gllut3D.cpp b/src/libkwineffects/gllut3D.cpp
new file mode 100644
index 0000000000..828152f1e0
--- /dev/null
+++ b/src/libkwineffects/gllut3D.cpp
@@ -0,0 +1,88 @@
+/*
+    KWin - the KDE window manager
+    This file is part of the KDE project.
+
+    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#include "gllut3D.h"
+
+#include <vector>
+
+namespace KWin
+{
+
+GlLookUpTable3D::GlLookUpTable3D(GLuint handle, size_t xSize, size_t ySize, size_t zSize)
+    : m_handle(handle)
+    , m_xSize(xSize)
+    , m_ySize(ySize)
+    , m_zSize(zSize)
+{
+}
+
+GlLookUpTable3D::~GlLookUpTable3D()
+{
+    glDeleteTextures(1, &m_handle);
+}
+
+GLuint GlLookUpTable3D::handle() const
+{
+    return m_handle;
+}
+
+size_t GlLookUpTable3D::xSize() const
+{
+    return m_xSize;
+}
+
+size_t GlLookUpTable3D::ySize() const
+{
+    return m_ySize;
+}
+
+size_t GlLookUpTable3D::zSize() const
+{
+    return m_zSize;
+}
+
+void GlLookUpTable3D::bind()
+{
+    glBindTexture(GL_TEXTURE_3D, m_handle);
+}
+
+std::unique_ptr<GlLookUpTable3D> GlLookUpTable3D::create(const std::function<QVector3D(size_t x, size_t y, size_t z)> &mapping, size_t xSize, size_t ySize, size_t zSize)
+{
+    GLuint handle = 0;
+    glGenTextures(1, &handle);
+    if (!handle) {
+        return nullptr;
+    }
+    glBindTexture(GL_TEXTURE_3D, handle);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAX_LEVEL, 0);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_LOD, 0);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAX_LOD, 0);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+    QVector<float> data;
+    data.reserve(4 * xSize * ySize * zSize);
+    for (size_t z = 0; z < zSize; z++) {
+        for (size_t y = 0; y < ySize; y++) {
+            for (size_t x = 0; x < xSize; x++) {
+                const auto color = mapping(x, y, z);
+                data.push_back(color.x());
+                data.push_back(color.y());
+                data.push_back(color.z());
+                data.push_back(1);
+            }
+        }
+    }
+    glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA16F, xSize, ySize, zSize, 0, GL_RGBA, GL_FLOAT, data.data());
+    glBindTexture(GL_TEXTURE_3D, 0);
+    return std::make_unique<GlLookUpTable3D>(handle, xSize, ySize, zSize);
+}
+
+}
diff --git a/src/libkwineffects/gllut3D.h b/src/libkwineffects/gllut3D.h
new file mode 100644
index 0000000000..569c1040c9
--- /dev/null
+++ b/src/libkwineffects/gllut3D.h
@@ -0,0 +1,44 @@
+/*
+    KWin - the KDE window manager
+    This file is part of the KDE project.
+
+    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+#pragma once
+
+#include "kwin_export.h"
+
+#include <QVector3D>
+#include <QVector>
+#include <epoxy/gl.h>
+#include <functional>
+#include <memory>
+
+namespace KWin
+{
+
+class KWIN_EXPORT GlLookUpTable3D
+{
+public:
+    explicit GlLookUpTable3D(GLuint handle, size_t xSize, size_t ySize, size_t zSize);
+    ~GlLookUpTable3D();
+
+    GLuint handle() const;
+    size_t xSize() const;
+    size_t ySize() const;
+    size_t zSize() const;
+
+    void bind();
+
+    static std::unique_ptr<GlLookUpTable3D> create(const std::function<QVector3D(size_t x, size_t y, size_t z)> &mapping, size_t xSize, size_t ySize, size_t zSize);
+
+private:
+    const GLuint m_handle;
+    const size_t m_xSize;
+    const size_t m_ySize;
+    const size_t m_zSize;
+};
+
+}