dali-toolkit/internal/text/controller/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/controller/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/rendering/styles/character-spacing-helper-functions.h>
  29 #include <dali-toolkit/internal/text/text-view.h>
  30
  31 namespace Dali::Toolkit::Text
  32 {
  33 namespace
  34 {
  35 struct BackgroundVertex
  36 {
  37   Vector2 mPosition; ///< Vertex posiiton
  38   Vector4 mColor;    ///< Vertex color
  39 };
  40
  41 struct BackgroundMesh
  42 {
  43   Vector<BackgroundVertex> mVertices; ///< container of vertices
  44   Vector<unsigned short>   mIndices;  ///< container of indices
  45 };
  46 } // unnamed namespace
  47
  48 Length CalculateBackgroundLineHeight(LineRun lineRun)
  49 {
  50   Length height = lineRun.ascender + -(lineRun.descender);
  51
  52   if(lineRun.lineSpacing > 0)
  53   {
  54     height += lineRun.lineSpacing;
  55   }
  56
  57   return height;
  58 }
  59
  60 Actor CreateControllerBackgroundActor(const View& textView, const VisualModelPtr& textVisualModel, const LogicalModelPtr& textLogicalModel, Shader& textShaderBackground)
  61 {
  62   // NOTE: Currently we only support background color for left-to-right text.
  63
  64   Actor actor;
  65
  66   Length numberOfGlyphs = textView.GetNumberOfGlyphs();
  67   if(numberOfGlyphs > 0u)
  68   {
  69     Vector<GlyphInfo> glyphs;
  70     glyphs.Resize(numberOfGlyphs);
  71
  72     Vector<Vector2> positions;
  73     positions.Resize(numberOfGlyphs);
  74
  75     // Get the line where the glyphs are laid-out.
  76     const LineRun* lineRun         = textVisualModel->mLines.Begin();
  77     float          alignmentOffset = lineRun->alignmentOffset;
  78     numberOfGlyphs                 = textView.GetGlyphs(glyphs.Begin(),
  79                                         positions.Begin(),
  80                                         alignmentOffset,
  81                                         0u,
  82                                         numberOfGlyphs);
  83
  84     glyphs.Resize(numberOfGlyphs);
  85     positions.Resize(numberOfGlyphs);
  86
  87     const GlyphInfo* const glyphsBuffer    = glyphs.Begin();
  88     const Vector2* const   positionsBuffer = positions.Begin();
  89
  90     BackgroundMesh mesh;
  91     mesh.mVertices.Reserve(4u * glyphs.Size());
  92     mesh.mIndices.Reserve(6u * glyphs.Size());
  93
  94     const Vector2 textSize = textView.GetLayoutSize();
  95
  96     const float offsetX = alignmentOffset + textSize.width * 0.5f;
  97     const float offsetY = textSize.height * 0.5f;
  98
  99     const Vector4* const    backgroundColorsBuffer       = textView.GetBackgroundColors();
 100     const ColorIndex* const backgroundColorIndicesBuffer = textView.GetBackgroundColorIndices();
 101     const Vector4&          defaultBackgroundColor       = textVisualModel->IsBackgroundEnabled() ? textVisualModel->GetBackgroundColor() : Color::TRANSPARENT;
 102     const float             modelCharacterSpacing        = textVisualModel->GetCharacterSpacing();
 103     Vector<CharacterIndex>& glyphToCharacterMap          = textVisualModel->mGlyphsToCharacters;
 104     const CharacterIndex*   glyphToCharacterMapBuffer    = glyphToCharacterMap.Begin();
 105     float                   calculatedAdvance            = 0.f;
 106
 107     // Get the character-spacing runs.
 108     const Vector<CharacterSpacingGlyphRun>& characterSpacingGlyphRuns = textVisualModel->GetCharacterSpacingGlyphRuns();
 109
 110     Vector4   quad;
 111     uint32_t  numberOfQuads = 0u;
 112     Length    yLineOffset   = 0;
 113     Length    prevLineIndex = 0;
 114     LineIndex lineIndex;
 115
 116     for(uint32_t i = 0, glyphSize = glyphs.Size(); i < glyphSize; ++i)
 117     {
 118       const GlyphInfo& glyph = *(glyphsBuffer + i);
 119
 120       // Get the background color of the character.
 121       // The color index zero is reserved for the default background color (i.e. Color::TRANSPARENT)
 122       const bool       isMarkupBackground       = textView.IsMarkupBackgroundColorSet();
 123       const ColorIndex backgroundColorIndex     = isMarkupBackground ? *(backgroundColorIndicesBuffer + i) : 0u;
 124       const bool       isDefaultBackgroundColor = (0u == backgroundColorIndex);
 125       const Vector4&   backgroundColor          = isDefaultBackgroundColor ? defaultBackgroundColor : *(backgroundColorsBuffer + backgroundColorIndex - 1u);
 126
 127       lineIndex         = textVisualModel->GetLineOfGlyph(i);
 128       Length lineHeight = CalculateBackgroundLineHeight(lineRun[lineIndex]);
 129
 130       if(lineIndex != prevLineIndex)
 131       {
 132         yLineOffset += CalculateBackgroundLineHeight(lineRun[prevLineIndex]);
 133
 134         if(lineRun[prevLineIndex].lineSpacing < 0)
 135         {
 136           yLineOffset += lineRun[prevLineIndex].lineSpacing;
 137         }
 138       }
 139
 140       // Only create quads for glyphs with a background color
 141       if(backgroundColor != Color::TRANSPARENT)
 142       {
 143         const float characterSpacing = GetGlyphCharacterSpacing(i, characterSpacingGlyphRuns, modelCharacterSpacing);
 144
 145         const Vector2 position = *(positionsBuffer + i);
 146         calculatedAdvance      = GetCalculatedAdvance(*(textLogicalModel->mText.Begin() + (*(glyphToCharacterMapBuffer + i))), characterSpacing, glyph.advance);
 147
 148         if(i == 0u && glyphSize == 1u) // Only one glyph in the whole text
 149         {
 150           quad.x = position.x;
 151           quad.y = yLineOffset;
 152           quad.z = quad.x + std::max(calculatedAdvance, glyph.xBearing + glyph.width);
 153           quad.w = lineHeight;
 154         }
 155         else if((lineIndex != prevLineIndex) || (i == 0u)) // The first glyph in the line
 156         {
 157           quad.x = position.x;
 158           quad.y = yLineOffset;
 159           quad.z = quad.x - glyph.xBearing + calculatedAdvance;
 160           quad.w = quad.y + lineHeight;
 161         }
 162         else if(i == glyphSize - 1u) // The last glyph in the whole text
 163         {
 164           quad.x = position.x - glyph.xBearing;
 165           quad.y = yLineOffset;
 166           quad.z = quad.x + std::max(calculatedAdvance, glyph.xBearing + glyph.width);
 167           quad.w = quad.y + lineHeight;
 168         }
 169         else // The glyph in the middle of the text
 170         {
 171           quad.x = position.x - glyph.xBearing;
 172           quad.y = yLineOffset;
 173           quad.z = quad.x + calculatedAdvance;
 174           quad.w = quad.y + lineHeight;
 175         }
 176
 177         BackgroundVertex vertex;
 178
 179         // Top left
 180         vertex.mPosition.x = quad.x - offsetX;
 181         vertex.mPosition.y = quad.y - offsetY;
 182         vertex.mColor      = backgroundColor;
 183         mesh.mVertices.PushBack(vertex);
 184
 185         // Top right
 186         vertex.mPosition.x = quad.z - offsetX;
 187         vertex.mPosition.y = quad.y - offsetY;
 188         vertex.mColor      = backgroundColor;
 189         mesh.mVertices.PushBack(vertex);
 190
 191         // Bottom left
 192         vertex.mPosition.x = quad.x - offsetX;
 193         vertex.mPosition.y = quad.w - offsetY;
 194         vertex.mColor      = backgroundColor;
 195         mesh.mVertices.PushBack(vertex);
 196
 197         // Bottom right
 198         vertex.mPosition.x = quad.z - offsetX;
 199         vertex.mPosition.y = quad.w - offsetY;
 200         vertex.mColor      = backgroundColor;
 201         mesh.mVertices.PushBack(vertex);
 202
 203         // Six indices in counter clockwise winding
 204         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 205         mesh.mIndices.PushBack(0u + 4 * numberOfQuads);
 206         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 207         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 208         mesh.mIndices.PushBack(3u + 4 * numberOfQuads);
 209         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 210
 211         numberOfQuads++;
 212       }
 213
 214       if(lineIndex != prevLineIndex)
 215       {
 216         prevLineIndex = lineIndex;
 217       }
 218     }
 219
 220     // Only create the background actor if there are glyphs with background color
 221     if(mesh.mVertices.Count() > 0u)
 222     {
 223       Property::Map quadVertexFormat;
 224       quadVertexFormat["aPosition"] = Property::VECTOR2;
 225       quadVertexFormat["aColor"]    = Property::VECTOR4;
 226
 227       VertexBuffer quadVertices = VertexBuffer::New(quadVertexFormat);
 228       quadVertices.SetData(&mesh.mVertices[0], mesh.mVertices.Size());
 229
 230       Geometry quadGeometry = Geometry::New();
 231       quadGeometry.AddVertexBuffer(quadVertices);
 232       quadGeometry.SetIndexBuffer(&mesh.mIndices[0], mesh.mIndices.Size());
 233
 234       if(!textShaderBackground)
 235       {
 236         textShaderBackground = Shader::New(SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_VERT, SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_FRAG);
 237       }
 238
 239       Dali::Renderer renderer = Dali::Renderer::New(quadGeometry, textShaderBackground);
 240       renderer.SetProperty(Dali::Renderer::Property::BLEND_MODE, BlendMode::ON);
 241       renderer.SetProperty(Dali::Renderer::Property::DEPTH_INDEX, DepthIndex::CONTENT);
 242
 243       actor = Actor::New();
 244       actor.SetProperty(Dali::Actor::Property::NAME, "TextBackgroundColorActor");
 245       actor.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_LEFT);
 246       actor.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_LEFT);
 247       actor.SetProperty(Actor::Property::SIZE, textSize);
 248       actor.SetProperty(Actor::Property::COLOR_MODE, USE_OWN_MULTIPLY_PARENT_COLOR);
 249       actor.AddRenderer(renderer);
 250     }
 251   }
 252
 253   return actor;
 254 }
 255
 256 } // namespace Dali::Toolkit::Text