Add distance field rendering to OpenGL runtime

The old text rendering remains in the background and is used to render
clipped text, since that feature is not yet implemented for distance
field fonts. Building the runtime with Qt version older than 5.12.2 also
causes a fallback to the old text rendering.

Depth pass rendering also needs to be redone in the future to avoid
another full render pass.

Task-number: QT3DS-3210
Change-Id: Ib7666c437d23ae25e1872682f010df3721476a14
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

1 files changed, 172 insertions, 0 deletions

diff --git a/src/Runtime/Source/runtimerender/Qt3DSDistanceFieldRenderer.h b/src/Runtime/Source/runtimerender/Qt3DSDistanceFieldRenderer.h
new file mode 100644
index 00000000..0e037fd8
--- /dev/null
+++ b/src/Runtime/Source/runtimerender/Qt3DSDistanceFieldRenderer.h
@@ -0,0 +1,172 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT3DSDISTANCEFIELDRENDERER_H
+#define QT3DSDISTANCEFIELDRENDERER_H
+
+#include "Qt3DSFontDatabase_p.h"
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,12,2)
+
+#include "Qt3DSTextRenderer.h"
+#include "Qt3DSRenderText.h"
+#include "render/Qt3DSRenderShaderProgram.h"
+
+#include "Qt3DSDistanceFieldGlyphCacheManager_p.h"
+#include "Qt3DSDistanceFieldGlyphCache_p.h"
+
+namespace qt3ds {
+namespace render {
+
+struct GlyphInfo {
+    QVector<float> vertexes;
+    QVector<quint32> glyphIndexes;
+    Q3DSDistanceFieldGlyphCache *cache;
+    float fontScale;
+    float shadowOffsetX;
+    float shadowOffsetY;
+    NVBounds3 bounds;
+};
+
+struct Q3DSDistanceFieldShader {
+    NVRenderShaderProgram *program = nullptr;
+    NVRenderCachedShaderProperty<QT3DSMat44> mvp;
+    NVRenderCachedShaderProperty<QT3DSMat44> modelView;
+    NVRenderCachedShaderProperty<QT3DSI32> textureWidth;
+    NVRenderCachedShaderProperty<QT3DSI32> textureHeight;
+    NVRenderCachedShaderProperty<QT3DSF32> fontScale;
+    NVRenderCachedShaderProperty<NVRenderTexture2D *> texture;
+    NVRenderCachedShaderProperty<QT3DSVec4> color;
+};
+
+struct Q3DSDistanceFieldDropShadowShader {
+    NVRenderShaderProgram *program = nullptr;
+    NVRenderCachedShaderProperty<QT3DSMat44> mvp;
+    NVRenderCachedShaderProperty<QT3DSMat44> modelView;
+    NVRenderCachedShaderProperty<QT3DSI32> textureWidth;
+    NVRenderCachedShaderProperty<QT3DSI32> textureHeight;
+    NVRenderCachedShaderProperty<QT3DSF32> fontScale;
+    NVRenderCachedShaderProperty<QT3DSVec2> shadowOffset;
+    NVRenderCachedShaderProperty<NVRenderTexture2D *> texture;
+    NVRenderCachedShaderProperty<QT3DSVec4> color;
+    NVRenderCachedShaderProperty<QT3DSVec4> shadowColor;
+};
+
+struct Q3DSDistanceFieldMesh
+{
+    NVRenderAttribLayout *attribLayout = nullptr;
+    NVRenderVertexBuffer *vertexBuffer = nullptr;
+    NVRenderIndexBuffer *indexBuffer = nullptr;
+    NVRenderInputAssembler *inputAssembler = nullptr;
+};
+
+class Q3DSDistanceFieldRenderer : public ITextRenderer
+{
+public:
+    Q3DSDistanceFieldRenderer(NVFoundationBase &foundation);
+    ~Q3DSDistanceFieldRenderer() override;
+    QHash<Q3DSDistanceFieldGlyphCache::TextureInfo *, GlyphInfo> buildGlyphsPerTexture(
+            const SText &textInfo);
+    void buildShaders();
+    Q3DSDistanceFieldMesh buildMesh(const GlyphInfo &glyphInfo, bool shadow);
+    void renderMesh(NVRenderInputAssembler *inputAssembler,
+                    NVRenderTexture2D *texture, const QT3DSMat44 &mvp,
+                    const QT3DSMat44 &modelView, QT3DSI32 textureWidth,
+                    QT3DSI32 textureHeight, QT3DSF32 fontScale, QT3DSVec4 color);
+    void renderMeshWithDropShadow(NVRenderInputAssembler *inputAssembler,
+                                  NVRenderTexture2D *texture, const QT3DSMat44 &mvp,
+                                  const QT3DSMat44 &modelView, QT3DSI32 textureWidth,
+                                  QT3DSI32 textureHeight, QT3DSF32 fontScale,
+                                  QT3DSVec2 shadowOffset, QT3DSVec4 color, QT3DSVec4 shadowColor);
+    void renderText(SText &text, const QT3DSMat44 &mvp, const QT3DSMat44 &modelView);
+    void renderTextDepth(SText &text, const QT3DSMat44 &mvp, const QT3DSMat44 &modelView);
+    void setContext(IQt3DSRenderContext &context);
+
+    QT3DS_IMPLEMENT_REF_COUNT_ADDREF_RELEASE_OVERRIDE(m_foundation.getAllocator())
+
+    void AddSystemFontDirectory(const char8_t *dir) override;
+    void AddProjectFontDirectory(const char8_t *dir) override;
+    void ClearProjectFontDirectories() override;
+    ITextRenderer &GetTextRenderer(NVRenderContext &) override;
+    void EndFrame() override;
+
+    // Unused methods:
+    void PreloadFonts() override;
+    void BeginPreloadFonts(IThreadPool &, IPerfTimer &) override;
+    void EndPreloadFonts() override;
+    void ReloadFonts() override;
+
+    NVConstDataRef<SRendererFontEntry> GetProjectFontList() override;
+
+    Option<CRegisteredString> GetFontNameForFont(CRegisteredString) override;
+    Option<CRegisteredString> GetFontNameForFont(const char8_t *) override;
+
+    STextDimensions MeasureText(const STextRenderInfo &, QT3DSF32,
+                                const char8_t *) override;
+
+    STextTextureDetails RenderText(const STextRenderInfo &,
+                                   NVRenderTexture2D &) override;
+
+    STextTextureDetails RenderText(const STextRenderInfo &, NVRenderPathFontItem &,
+                                   NVRenderPathFontSpecification &) override;
+
+    SRenderTextureAtlasDetails RenderText(const STextRenderInfo &) override;
+
+    void BeginFrame() override;
+
+    QT3DSI32 CreateTextureAtlas() override;
+    STextTextureAtlasEntryDetails RenderAtlasEntry(QT3DSU32, NVRenderTexture2D &) override;
+
+private:
+    IQt3DSRenderContext *m_context = nullptr;
+    QHash<size_t, QHash<Q3DSDistanceFieldGlyphCache::TextureInfo *, GlyphInfo>> m_glyphCache;
+    QHash<size_t, Q3DSDistanceFieldMesh> m_meshCache;
+
+    Q3DSFontDatabase m_fontDatabase;
+    Q3DSDistanceFieldGlyphCacheManager m_glyphCacheManager;
+
+    Q3DSDistanceFieldShader m_shader;
+    Q3DSDistanceFieldDropShadowShader m_dropShadowShader;
+    QVector<size_t> m_renderedGlyphs;
+
+    QStringList m_systemDirs;
+    QStringList m_projectDirs;
+
+    qreal m_pixelRatio = 0.0;
+
+    NVFoundationBase &m_foundation;
+    volatile QT3DSI32 mRefCount = 0;
+};
+
+}
+}
+
+#endif // Qt version check
+
+#endif // QT3DSDISTANCEFIELDRENDERER_H