dali-toolkit/internal/text/text-controller-background-actor.cpp

   1 /*
   2  * Copyright (c) 2022 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 // HEADER
  19 #include <dali-toolkit/internal/text/text-controller-background-actor.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <dali/public-api/rendering/renderer.h>
  23
  24 // INTERNAL INCLUDES
  25 #include <dali-toolkit/devel-api/controls/control-depth-index-ranges.h>
  26 #include <dali-toolkit/internal/graphics/builtin-shader-extern-gen.h>
  27 #include <dali-toolkit/internal/text/cursor-helper-functions.h>
  28 #include <dali-toolkit/internal/text/text-view.h>
  29
  30 namespace Dali::Toolkit::Text
  31 {
  32 namespace
  33 {
  34 struct BackgroundVertex
  35 {
  36   Vector2 mPosition; ///< Vertex posiiton
  37   Vector4 mColor;    ///< Vertex color
  38 };
  39
  40 struct BackgroundMesh
  41 {
  42   Vector<BackgroundVertex> mVertices; ///< container of vertices
  43   Vector<unsigned short>   mIndices;  ///< container of indices
  44 };
  45 } // unnamed namespace
  46
  47 Length CalculateBackgroundLineHeight(LineRun lineRun)
  48 {
  49   Length height = lineRun.ascender + -(lineRun.descender);
  50
  51   if(lineRun.lineSpacing > 0)
  52   {
  53     height += lineRun.lineSpacing;
  54   }
  55
  56   return height;
  57 }
  58
  59 Actor CreateControllerBackgroundActor(const View& textView, const VisualModelPtr& textVisualModel, const LogicalModelPtr& textLogicalModel, Shader& textShaderBackground)
  60 {
  61   // NOTE: Currently we only support background color for left-to-right text.
  62
  63   Actor actor;
  64
  65   Length numberOfGlyphs = textView.GetNumberOfGlyphs();
  66   if(numberOfGlyphs > 0u)
  67   {
  68     Vector<GlyphInfo> glyphs;
  69     glyphs.Resize(numberOfGlyphs);
  70
  71     Vector<Vector2> positions;
  72     positions.Resize(numberOfGlyphs);
  73
  74     // Get the line where the glyphs are laid-out.
  75     const LineRun* lineRun         = textVisualModel->mLines.Begin();
  76     float          alignmentOffset = lineRun->alignmentOffset;
  77     numberOfGlyphs                 = textView.GetGlyphs(glyphs.Begin(),
  78                                         positions.Begin(),
  79                                         alignmentOffset,
  80                                         0u,
  81                                         numberOfGlyphs);
  82
  83     glyphs.Resize(numberOfGlyphs);
  84     positions.Resize(numberOfGlyphs);
  85
  86     const GlyphInfo* const glyphsBuffer    = glyphs.Begin();
  87     const Vector2* const   positionsBuffer = positions.Begin();
  88
  89     BackgroundMesh mesh;
  90     mesh.mVertices.Reserve(4u * glyphs.Size());
  91     mesh.mIndices.Reserve(6u * glyphs.Size());
  92
  93     const Vector2 textSize = textView.GetLayoutSize();
  94
  95     const float offsetX = alignmentOffset + textSize.width * 0.5f;
  96     const float offsetY = textSize.height * 0.5f;
  97
  98     const Vector4* const    backgroundColorsBuffer       = textView.GetBackgroundColors();
  99     const ColorIndex* const backgroundColorIndicesBuffer = textView.GetBackgroundColorIndices();
 100     const Vector4&          defaultBackgroundColor       = textVisualModel->IsBackgroundEnabled() ? textVisualModel->GetBackgroundColor() : Color::TRANSPARENT;
 101     const float             characterSpacing             = textVisualModel->GetCharacterSpacing();
 102     Vector<CharacterIndex>& glyphToCharacterMap          = textVisualModel->mGlyphsToCharacters;
 103     const CharacterIndex*   glyphToCharacterMapBuffer    = glyphToCharacterMap.Begin();
 104     float                   calculatedAdvance            = 0.f;
 105
 106     Vector4   quad;
 107     uint32_t  numberOfQuads = 0u;
 108     Length    yLineOffset   = 0;
 109     Length    prevLineIndex = 0;
 110     LineIndex lineIndex;
 111     Length    numberOfLines;
 112
 113     for(uint32_t i = 0, glyphSize = glyphs.Size(); i < glyphSize; ++i)
 114     {
 115       const GlyphInfo& glyph = *(glyphsBuffer + i);
 116
 117       // Get the background color of the character.
 118       // The color index zero is reserved for the default background color (i.e. Color::TRANSPARENT)
 119       const bool       isMarkupBackground       = textView.IsMarkupBackgroundColorSet();
 120       const ColorIndex backgroundColorIndex     = isMarkupBackground ? *(backgroundColorIndicesBuffer + i) : 0u;
 121       const bool       isDefaultBackgroundColor = (0u == backgroundColorIndex);
 122       const Vector4&   backgroundColor          = isDefaultBackgroundColor ? defaultBackgroundColor : *(backgroundColorsBuffer + backgroundColorIndex - 1u);
 123
 124       textVisualModel->GetNumberOfLines(i, 1, lineIndex, numberOfLines);
 125       Length lineHeight = CalculateBackgroundLineHeight(lineRun[lineIndex]);
 126
 127       if(lineIndex != prevLineIndex)
 128       {
 129         yLineOffset += CalculateBackgroundLineHeight(lineRun[prevLineIndex]);
 130
 131         if(lineRun[prevLineIndex].lineSpacing < 0)
 132         {
 133           yLineOffset += lineRun[prevLineIndex].lineSpacing;
 134         }
 135       }
 136
 137       // Only create quads for glyphs with a background color
 138       if(backgroundColor != Color::TRANSPARENT)
 139       {
 140         const Vector2 position = *(positionsBuffer + i);
 141         calculatedAdvance      = GetCalculatedAdvance(*(textLogicalModel->mText.Begin() + (*(glyphToCharacterMapBuffer + i))), characterSpacing, glyph.advance);
 142
 143         if(i == 0u && glyphSize == 1u) // Only one glyph in the whole text
 144         {
 145           quad.x = position.x;
 146           quad.y = yLineOffset;
 147           quad.z = quad.x + std::max(calculatedAdvance, glyph.xBearing + glyph.width);
 148           quad.w = lineHeight;
 149         }
 150         else if((lineIndex != prevLineIndex) || (i == 0u)) // The first glyph in the line
 151         {
 152           quad.x = position.x;
 153           quad.y = yLineOffset;
 154           quad.z = quad.x - glyph.xBearing + calculatedAdvance;
 155           quad.w = quad.y + lineHeight;
 156         }
 157         else if(i == glyphSize - 1u) // The last glyph in the whole text
 158         {
 159           quad.x = position.x - glyph.xBearing;
 160           quad.y = yLineOffset;
 161           quad.z = quad.x + std::max(calculatedAdvance, glyph.xBearing + glyph.width);
 162           quad.w = quad.y + lineHeight;
 163         }
 164         else // The glyph in the middle of the text
 165         {
 166           quad.x = position.x - glyph.xBearing;
 167           quad.y = yLineOffset;
 168           quad.z = quad.x + calculatedAdvance;
 169           quad.w = quad.y + lineHeight;
 170         }
 171
 172         BackgroundVertex vertex;
 173
 174         // Top left
 175         vertex.mPosition.x = quad.x - offsetX;
 176         vertex.mPosition.y = quad.y - offsetY;
 177         vertex.mColor      = backgroundColor;
 178         mesh.mVertices.PushBack(vertex);
 179
 180         // Top right
 181         vertex.mPosition.x = quad.z - offsetX;
 182         vertex.mPosition.y = quad.y - offsetY;
 183         vertex.mColor      = backgroundColor;
 184         mesh.mVertices.PushBack(vertex);
 185
 186         // Bottom left
 187         vertex.mPosition.x = quad.x - offsetX;
 188         vertex.mPosition.y = quad.w - offsetY;
 189         vertex.mColor      = backgroundColor;
 190         mesh.mVertices.PushBack(vertex);
 191
 192         // Bottom right
 193         vertex.mPosition.x = quad.z - offsetX;
 194         vertex.mPosition.y = quad.w - offsetY;
 195         vertex.mColor      = backgroundColor;
 196         mesh.mVertices.PushBack(vertex);
 197
 198         // Six indices in counter clockwise winding
 199         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 200         mesh.mIndices.PushBack(0u + 4 * numberOfQuads);
 201         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 202         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 203         mesh.mIndices.PushBack(3u + 4 * numberOfQuads);
 204         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 205
 206         numberOfQuads++;
 207       }
 208
 209       if(lineIndex != prevLineIndex)
 210       {
 211         prevLineIndex = lineIndex;
 212       }
 213     }
 214
 215     // Only create the background actor if there are glyphs with background color
 216     if(mesh.mVertices.Count() > 0u)
 217     {
 218       Property::Map quadVertexFormat;
 219       quadVertexFormat["aPosition"] = Property::VECTOR2;
 220       quadVertexFormat["aColor"]    = Property::VECTOR4;
 221
 222       VertexBuffer quadVertices = VertexBuffer::New(quadVertexFormat);
 223       quadVertices.SetData(&mesh.mVertices[0], mesh.mVertices.Size());
 224
 225       Geometry quadGeometry = Geometry::New();
 226       quadGeometry.AddVertexBuffer(quadVertices);
 227       quadGeometry.SetIndexBuffer(&mesh.mIndices[0], mesh.mIndices.Size());
 228
 229       if(!textShaderBackground)
 230       {
 231         textShaderBackground = Shader::New(SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_VERT, SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_FRAG);
 232       }
 233
 234       Dali::Renderer renderer = Dali::Renderer::New(quadGeometry, textShaderBackground);
 235       renderer.SetProperty(Dali::Renderer::Property::BLEND_MODE, BlendMode::ON);
 236       renderer.SetProperty(Dali::Renderer::Property::DEPTH_INDEX, DepthIndex::CONTENT);
 237
 238       actor = Actor::New();
 239       actor.SetProperty(Dali::Actor::Property::NAME, "TextBackgroundColorActor");
 240       actor.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_LEFT);
 241       actor.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_LEFT);
 242       actor.SetProperty(Actor::Property::SIZE, textSize);
 243       actor.SetProperty(Actor::Property::COLOR_MODE, USE_OWN_MULTIPLY_PARENT_COLOR);
 244       actor.AddRenderer(renderer);
 245     }
 246   }
 247
 248   return actor;
 249 }
 250
 251 } // namespace Dali::Toolkit::Text