Label legibility improvements: pitch-scaling and pitched line-following

cmake/core-files.cmake

@@ -97,6 +97,8 @@ set(MBGL_CORE_FILES
     src/mbgl/layout/symbol_instance.hpp
     src/mbgl/layout/symbol_layout.cpp
     src/mbgl/layout/symbol_layout.hpp
+    src/mbgl/layout/symbol_projection.cpp
+    src/mbgl/layout/symbol_projection.hpp
 
     # map
     include/mbgl/map/backend.hpp

src/mbgl/algorithm/update_renderables.hpp

@@ -31,7 +31,7 @@ void updateRenderables(GetTileFn getTile,
         assert(idealRenderTileID.canonical.z <= zoomRange.max);
         assert(dataTileZoom >= idealRenderTileID.canonical.z);
 
-        const OverscaledTileID idealDataTileID(dataTileZoom, idealRenderTileID.canonical);
+        const OverscaledTileID idealDataTileID(dataTileZoom, idealRenderTileID.wrap, idealRenderTileID.canonical);
         auto tile = getTile(idealDataTileID);
         if (!tile) {
             tile = createTile(idealDataTileID);
@@ -64,11 +64,11 @@ void updateRenderables(GetTileFn getTile,
             } else {
                 // Check all four actual child tiles.
                 for (const auto& childTileID : idealDataTileID.canonical.children()) {
-                    const OverscaledTileID childDataTileID(overscaledZ, childTileID);
+                    const OverscaledTileID childDataTileID(overscaledZ, idealRenderTileID.wrap, childTileID);
                     tile = getTile(childDataTileID);
                     if (tile && tile->isRenderable()) {
                         retainTile(*tile, Resource::Necessity::Optional);
-                        renderTile(childDataTileID.unwrapTo(idealRenderTileID.wrap), *tile);
+                        renderTile(childDataTileID.toUnwrapped(), *tile);
                     } else {
                         // At least one child tile doesn't exist, so we are going to look for
                         // parents as well.
@@ -81,8 +81,7 @@ void updateRenderables(GetTileFn getTile,
                 // We couldn't find child tiles that entirely cover the ideal tile.
                 for (overscaledZ = dataTileZoom - 1; overscaledZ >= zoomRange.min; --overscaledZ) {
                     const auto parentDataTileID = idealDataTileID.scaledTo(overscaledZ);
-                    const auto parentRenderTileID =
-                        parentDataTileID.unwrapTo(idealRenderTileID.wrap);
+                    const auto parentRenderTileID = parentDataTileID.toUnwrapped();
 
                     if (checked.find(parentRenderTileID) != checked.end()) {
                         // Break parent tile ascent, this route has been checked by another child

src/mbgl/gl/context.cpp

@@ -16,6 +16,31 @@ namespace gl {
 static_assert(underlying_type(ShaderType::Vertex) == GL_VERTEX_SHADER, "OpenGL type mismatch");
 static_assert(underlying_type(ShaderType::Fragment) == GL_FRAGMENT_SHADER, "OpenGL type mismatch");
 
+static_assert(underlying_type(DataType::Byte) == GL_BYTE, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::UnsignedByte) == GL_UNSIGNED_BYTE, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::Short) == GL_SHORT, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::UnsignedShort) == GL_UNSIGNED_SHORT, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::Integer) == GL_INT, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::UnsignedInteger) == GL_UNSIGNED_INT, "OpenGL type mismatch");
+static_assert(underlying_type(DataType::Float) == GL_FLOAT, "OpenGL type mismatch");
+
+#if not MBGL_USE_GLES2
+static_assert(underlying_type(RenderbufferType::RGBA) == GL_RGBA8, "OpenGL type mismatch");
+#else
+static_assert(underlying_type(RenderbufferType::RGBA) == GL_RGBA8_OES, "OpenGL type mismatch");
+#endif // MBGL_USE_GLES2
+#if not MBGL_USE_GLES2
+static_assert(underlying_type(RenderbufferType::DepthStencil) == GL_DEPTH24_STENCIL8, "OpenGL type mismatch");
+#else
+static_assert(underlying_type(RenderbufferType::DepthStencil) == GL_DEPTH24_STENCIL8_OES, "OpenGL type mismatch");
+#endif // MBGL_USE_GLES2
+#if not MBGL_USE_GLES2
+static_assert(underlying_type(RenderbufferType::DepthComponent) == GL_DEPTH_COMPONENT, "OpenGL type mismatch");
+#else
+static_assert(underlying_type(RenderbufferType::DepthComponent) == GL_DEPTH_COMPONENT16, "OpenGL type mismatch");
+#endif // MBGL_USE_GLES2
+
+
 static_assert(underlying_type(PrimitiveType::Points) == GL_POINTS, "OpenGL type mismatch");
 static_assert(underlying_type(PrimitiveType::Lines) == GL_LINES, "OpenGL type mismatch");
 static_assert(underlying_type(PrimitiveType::LineLoop) == GL_LINE_LOOP, "OpenGL type mismatch");
@@ -36,6 +61,28 @@ static_assert(std::is_same<std::underlying_type_t<TextureFormat>, GLenum>::value
 static_assert(underlying_type(TextureFormat::RGBA) == GL_RGBA, "OpenGL type mismatch");
 static_assert(underlying_type(TextureFormat::Alpha) == GL_ALPHA, "OpenGL type mismatch");
 
+static_assert(underlying_type(UniformDataType::Float) == GL_FLOAT, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatVec2) == GL_FLOAT_VEC2, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatVec3) == GL_FLOAT_VEC3, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatVec4) == GL_FLOAT_VEC4, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::Int) == GL_INT, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::IntVec2) == GL_INT_VEC2, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::IntVec3) == GL_INT_VEC3, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::IntVec4) == GL_INT_VEC4, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::Bool) == GL_BOOL, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::BoolVec2) == GL_BOOL_VEC2, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::BoolVec3) == GL_BOOL_VEC3, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::BoolVec4) == GL_BOOL_VEC4, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatMat2) == GL_FLOAT_MAT2, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatMat3) == GL_FLOAT_MAT3, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::FloatMat4) == GL_FLOAT_MAT4, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::Sampler2D) == GL_SAMPLER_2D, "OpenGL type mismatch");
+static_assert(underlying_type(UniformDataType::SamplerCube) == GL_SAMPLER_CUBE, "OpenGL type mismatch");
+
+static_assert(underlying_type(BufferUsage::StreamDraw) == GL_STREAM_DRAW, "OpenGL type mismatch");
+static_assert(underlying_type(BufferUsage::StaticDraw) == GL_STATIC_DRAW, "OpenGL type mismatch");
+static_assert(underlying_type(BufferUsage::DynamicDraw) == GL_DYNAMIC_DRAW, "OpenGL type mismatch");
+
 static_assert(std::is_same<BinaryProgramFormat, GLenum>::value, "OpenGL type mismatch");
 
 Context::Context() = default;
@@ -164,15 +211,20 @@ void Context::verifyProgramLinkage(ProgramID program_) {
     throw std::runtime_error("program failed to link");
 }
 
-UniqueBuffer Context::createVertexBuffer(const void* data, std::size_t size) {
+UniqueBuffer Context::createVertexBuffer(const void* data, std::size_t size, const BufferUsage usage) {
     BufferID id = 0;
     MBGL_CHECK_ERROR(glGenBuffers(1, &id));
     UniqueBuffer result { std::move(id), { this } };
     vertexBuffer = result;
-    MBGL_CHECK_ERROR(glBufferData(GL_ARRAY_BUFFER, size, data, GL_STATIC_DRAW));
+    MBGL_CHECK_ERROR(glBufferData(GL_ARRAY_BUFFER, size, data, static_cast<GLenum>(usage)));
     return result;
 }
 
+void Context::updateVertexBuffer(UniqueBuffer& buffer, const void* data, std::size_t size) {
+    vertexBuffer = buffer;
+    MBGL_CHECK_ERROR(glBufferSubData(GL_ARRAY_BUFFER, 0, size, data));
+}
+
 UniqueBuffer Context::createIndexBuffer(const void* data, std::size_t size) {
     BufferID id = 0;
     MBGL_CHECK_ERROR(glGenBuffers(1, &id));

src/mbgl/gl/context.hpp

@@ -65,13 +65,19 @@ class Context : private util::noncopyable {
     optional<std::pair<BinaryProgramFormat, std::string>> getBinaryProgram(ProgramID) const;
 
     template <class Vertex, class DrawMode>
-    VertexBuffer<Vertex, DrawMode> createVertexBuffer(VertexVector<Vertex, DrawMode>&& v) {
+    VertexBuffer<Vertex, DrawMode> createVertexBuffer(VertexVector<Vertex, DrawMode>&& v, const BufferUsage usage=BufferUsage::StaticDraw) {
         return VertexBuffer<Vertex, DrawMode> {
             v.vertexSize(),
-            createVertexBuffer(v.data(), v.byteSize())
+            createVertexBuffer(v.data(), v.byteSize(), usage)
         };
     }
 
+    template <class Vertex, class DrawMode>
+    void updateVertexBuffer(VertexBuffer<Vertex, DrawMode>& buffer, VertexVector<Vertex, DrawMode>&& v) {
+        assert(v.vertexSize() == buffer.vertexCount);
+        updateVertexBuffer(buffer.buffer, v.data(), v.byteSize());
+    }
+
     template <class DrawMode>
     IndexBuffer<DrawMode> createIndexBuffer(IndexVector<DrawMode>&& v) {
         return IndexBuffer<DrawMode> {
@@ -239,7 +245,8 @@ class Context : private util::noncopyable {
     State<value::PointSize> pointSize;
 #endif // MBGL_USE_GLES2
 
-    UniqueBuffer createVertexBuffer(const void* data, std::size_t size);
+    UniqueBuffer createVertexBuffer(const void* data, std::size_t size, const BufferUsage usage);
+    void updateVertexBuffer(UniqueBuffer& buffer, const void* data, std::size_t size);
     UniqueBuffer createIndexBuffer(const void* data, std::size_t size);
     UniqueTexture createTexture(Size size, const void* data, TextureFormat, TextureUnit);
     void updateTexture(TextureID, Size size, const void* data, TextureFormat, TextureUnit);

src/mbgl/gl/types.hpp

@@ -96,5 +96,11 @@ enum class UniformDataType : uint32_t {
     SamplerCube = 0x8B60,
 };
 
+enum class BufferUsage : uint32_t {
+    StreamDraw = 0x88E0,
+    StaticDraw = 0x88E4,
+    DynamicDraw = 0x88E8,
+};
+
 } // namespace gl
 } // namespace mbgl

src/mbgl/layout/symbol_instance.cpp

@@ -5,8 +5,8 @@ namespace mbgl {
 
 using namespace style;
 
-SymbolInstance::SymbolInstance(Anchor& anchor,
-                               const GeometryCoordinates& line,
+SymbolInstance::SymbolInstance(Anchor& anchor_,
+                               GeometryCoordinates line_,
                                const std::pair<Shaping, Shaping>& shapedTextOrientations,
                                optional<PositionedIcon> shapedIcon,
                                const SymbolLayoutProperties::Evaluated& layout,
@@ -16,33 +16,38 @@ SymbolInstance::SymbolInstance(Anchor& anchor,
                                const float textBoxScale,
                                const float textPadding,
                                const SymbolPlacementType textPlacement,
+                               const std::array<float, 2> textOffset_,
                                const float iconBoxScale,
                                const float iconPadding,
                                const SymbolPlacementType iconPlacement,
+                               const std::array<float, 2> iconOffset_,
                                const GlyphPositionMap& positions,
                                const IndexedSubfeature& indexedFeature,
                                const std::size_t featureIndex_) :
-    point(anchor.point),
+    anchor(anchor_),
+    line(line_),
     index(index_),
     hasText(shapedTextOrientations.first || shapedTextOrientations.second),
     hasIcon(shapedIcon),
 
     // Create the collision features that will be used to check whether this symbol instance can be placed
-    textCollisionFeature(line, anchor, shapedTextOrientations.second ?: shapedTextOrientations.first, textBoxScale, textPadding, textPlacement, indexedFeature),
-    iconCollisionFeature(line, anchor, shapedIcon, iconBoxScale, iconPadding, iconPlacement, indexedFeature),
-    featureIndex(featureIndex_) {
+    textCollisionFeature(line_, anchor, shapedTextOrientations.second ?: shapedTextOrientations.first, textBoxScale, textPadding, textPlacement, indexedFeature),
+    iconCollisionFeature(line_, anchor, shapedIcon, iconBoxScale, iconPadding, iconPlacement, indexedFeature),
+    featureIndex(featureIndex_),
+    textOffset(textOffset_),
+    iconOffset(iconOffset_) {
 
     // Create the quads used for rendering the icon and glyphs.
     if (addToBuffers) {
         if (shapedIcon) {
-            iconQuad = getIconQuad(anchor, *shapedIcon, line, layout, layoutTextSize, iconPlacement, shapedTextOrientations.first);
+            iconQuad = getIconQuad(*shapedIcon, layout, layoutTextSize, shapedTextOrientations.first);
         }
         if (shapedTextOrientations.first) {
-            auto quads = getGlyphQuads(anchor, shapedTextOrientations.first, textBoxScale, line, layout, textPlacement, positions);
+            auto quads = getGlyphQuads(shapedTextOrientations.first, layout, textPlacement, positions);
             glyphQuads.insert(glyphQuads.end(), quads.begin(), quads.end());
         }
         if (shapedTextOrientations.second) {
-            auto quads = getGlyphQuads(anchor, shapedTextOrientations.second, textBoxScale, line, layout, textPlacement, positions);
+            auto quads = getGlyphQuads(shapedTextOrientations.second, layout, textPlacement, positions);
             glyphQuads.insert(glyphQuads.end(), quads.begin(), quads.end());
         }
     }

src/mbgl/layout/symbol_instance.hpp

@@ -13,7 +13,7 @@ class IndexedSubfeature;
 class SymbolInstance {
 public:
     SymbolInstance(Anchor& anchor,
-                   const GeometryCoordinates& line,
+                   GeometryCoordinates line,
                    const std::pair<Shaping, Shaping>& shapedTextOrientations,
                    optional<PositionedIcon> shapedIcon,
                    const style::SymbolLayoutProperties::Evaluated&,
@@ -23,14 +23,17 @@ class SymbolInstance {
                    const float textBoxScale,
                    const float textPadding,
                    style::SymbolPlacementType textPlacement,
+                   const std::array<float, 2> textOffset,
                    const float iconBoxScale,
                    const float iconPadding,
                    style::SymbolPlacementType iconPlacement,
+                   const std::array<float, 2> iconOffset,
                    const GlyphPositionMap&,
                    const IndexedSubfeature&,
                    const std::size_t featureIndex);
 
-    Point<float> point;
+    Anchor anchor;
+    GeometryCoordinates line;
     uint32_t index;
     bool hasText;
     bool hasIcon;
@@ -40,6 +43,8 @@ class SymbolInstance {
     CollisionFeature iconCollisionFeature;
     WritingModeType writingModes;
     std::size_t featureIndex;
+    std::array<float, 2> textOffset;
+    std::array<float, 2> iconOffset;
 };
 
 } // namespace mbgl