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

   1 /*
   2  * Copyright (c) 2021 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/text-view.h>
  28
  29 namespace Dali::Toolkit::Text
  30 {
  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 Actor CreateControllerBackgroundActor(const View& textView, const VisualModelPtr& textVisualModel, Shader& textShaderBackground)
  48 {
  49   // NOTE: Currently we only support background color for left-to-right text.
  50
  51   Actor actor;
  52
  53   Length numberOfGlyphs = textView.GetNumberOfGlyphs();
  54   if(numberOfGlyphs > 0u)
  55   {
  56     Vector<GlyphInfo> glyphs;
  57     glyphs.Resize(numberOfGlyphs);
  58
  59     Vector<Vector2> positions;
  60     positions.Resize(numberOfGlyphs);
  61
  62     // Get the line where the glyphs are laid-out.
  63     const LineRun* lineRun         = textVisualModel->mLines.Begin();
  64     float          alignmentOffset = lineRun->alignmentOffset;
  65     numberOfGlyphs                 = textView.GetGlyphs(glyphs.Begin(),
  66                                                      positions.Begin(),
  67                                                      alignmentOffset,
  68                                                      0u,
  69                                                      numberOfGlyphs);
  70
  71     glyphs.Resize(numberOfGlyphs);
  72     positions.Resize(numberOfGlyphs);
  73
  74     const GlyphInfo* const glyphsBuffer    = glyphs.Begin();
  75     const Vector2* const   positionsBuffer = positions.Begin();
  76
  77     BackgroundMesh mesh;
  78     mesh.mVertices.Reserve(4u * glyphs.Size());
  79     mesh.mIndices.Reserve(6u * glyphs.Size());
  80
  81     const Vector2 textSize = textView.GetLayoutSize();
  82
  83     const float offsetX = alignmentOffset + textSize.width * 0.5f;
  84     const float offsetY = textSize.height * 0.5f;
  85
  86     const Vector4* const    backgroundColorsBuffer       = textView.GetBackgroundColors();
  87     const ColorIndex* const backgroundColorIndicesBuffer = textView.GetBackgroundColorIndices();
  88     const Vector4&          defaultBackgroundColor       = textVisualModel->IsBackgroundEnabled() ? textVisualModel->GetBackgroundColor() : Color::TRANSPARENT;
  89
  90     Vector4   quad;
  91     uint32_t  numberOfQuads = 0u;
  92     Length    yLineOffset   = 0;
  93     Length    prevLineIndex = 0;
  94     LineIndex lineIndex;
  95     Length    numberOfLines;
  96
  97     for(uint32_t i = 0, glyphSize = glyphs.Size(); i < glyphSize; ++i)
  98     {
  99       const GlyphInfo& glyph = *(glyphsBuffer + i);
 100
 101       // Get the background color of the character.
 102       // The color index zero is reserved for the default background color (i.e. Color::TRANSPARENT)
 103       const bool       isMarkupBackground       = textView.IsMarkupBackgroundColorSet();
 104       const ColorIndex backgroundColorIndex     = isMarkupBackground ? *(backgroundColorIndicesBuffer + i) : 0u;
 105       const bool       isDefaultBackgroundColor = (0u == backgroundColorIndex);
 106       const Vector4&   backgroundColor          = isDefaultBackgroundColor ? defaultBackgroundColor : *(backgroundColorsBuffer + backgroundColorIndex - 1u);
 107
 108       textVisualModel->GetNumberOfLines(i, 1, lineIndex, numberOfLines);
 109       Length lineHeight = lineRun[lineIndex].ascender + -(lineRun[lineIndex].descender) + lineRun[lineIndex].lineSpacing;
 110
 111       if(lineIndex != prevLineIndex)
 112       {
 113         yLineOffset += lineHeight;
 114       }
 115
 116       // Only create quads for glyphs with a background color
 117       if(backgroundColor != Color::TRANSPARENT)
 118       {
 119         const Vector2 position = *(positionsBuffer + i);
 120
 121         if(i == 0u && glyphSize == 1u) // Only one glyph in the whole text
 122         {
 123           quad.x = position.x;
 124           quad.y = yLineOffset;
 125           quad.z = quad.x + std::max(glyph.advance, glyph.xBearing + glyph.width);
 126           quad.w = lineHeight;
 127         }
 128         else if((lineIndex != prevLineIndex) || (i == 0u)) // The first glyph in the line
 129         {
 130           quad.x = position.x;
 131           quad.y = yLineOffset;
 132           quad.z = quad.x - glyph.xBearing + glyph.advance;
 133           quad.w = quad.y + lineHeight;
 134         }
 135         else if(i == glyphSize - 1u) // The last glyph in the whole text
 136         {
 137           quad.x = position.x - glyph.xBearing;
 138           quad.y = yLineOffset;
 139           quad.z = quad.x + std::max(glyph.advance, glyph.xBearing + glyph.width);
 140           quad.w = quad.y + lineHeight;
 141         }
 142         else // The glyph in the middle of the text
 143         {
 144           quad.x = position.x - glyph.xBearing;
 145           quad.y = yLineOffset;
 146           quad.z = quad.x + glyph.advance;
 147           quad.w = quad.y + lineHeight;
 148         }
 149
 150         BackgroundVertex vertex;
 151
 152         // Top left
 153         vertex.mPosition.x = quad.x - offsetX;
 154         vertex.mPosition.y = quad.y - offsetY;
 155         vertex.mColor      = backgroundColor;
 156         mesh.mVertices.PushBack(vertex);
 157
 158         // Top right
 159         vertex.mPosition.x = quad.z - offsetX;
 160         vertex.mPosition.y = quad.y - offsetY;
 161         vertex.mColor      = backgroundColor;
 162         mesh.mVertices.PushBack(vertex);
 163
 164         // Bottom left
 165         vertex.mPosition.x = quad.x - offsetX;
 166         vertex.mPosition.y = quad.w - offsetY;
 167         vertex.mColor      = backgroundColor;
 168         mesh.mVertices.PushBack(vertex);
 169
 170         // Bottom right
 171         vertex.mPosition.x = quad.z - offsetX;
 172         vertex.mPosition.y = quad.w - offsetY;
 173         vertex.mColor      = backgroundColor;
 174         mesh.mVertices.PushBack(vertex);
 175
 176         // Six indices in counter clockwise winding
 177         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 178         mesh.mIndices.PushBack(0u + 4 * numberOfQuads);
 179         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 180         mesh.mIndices.PushBack(2u + 4 * numberOfQuads);
 181         mesh.mIndices.PushBack(3u + 4 * numberOfQuads);
 182         mesh.mIndices.PushBack(1u + 4 * numberOfQuads);
 183
 184         numberOfQuads++;
 185       }
 186
 187       if(lineIndex != prevLineIndex)
 188       {
 189         prevLineIndex = lineIndex;
 190       }
 191     }
 192
 193     // Only create the background actor if there are glyphs with background color
 194     if(mesh.mVertices.Count() > 0u)
 195     {
 196       Property::Map quadVertexFormat;
 197       quadVertexFormat["aPosition"] = Property::VECTOR2;
 198       quadVertexFormat["aColor"]    = Property::VECTOR4;
 199
 200       VertexBuffer quadVertices = VertexBuffer::New(quadVertexFormat);
 201       quadVertices.SetData(&mesh.mVertices[0], mesh.mVertices.Size());
 202
 203       Geometry quadGeometry = Geometry::New();
 204       quadGeometry.AddVertexBuffer(quadVertices);
 205       quadGeometry.SetIndexBuffer(&mesh.mIndices[0], mesh.mIndices.Size());
 206
 207       if(!textShaderBackground)
 208       {
 209         textShaderBackground = Shader::New(SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_VERT, SHADER_TEXT_CONTROLLER_BACKGROUND_SHADER_FRAG);
 210       }
 211
 212       Dali::Renderer renderer = Dali::Renderer::New(quadGeometry, textShaderBackground);
 213       renderer.SetProperty(Dali::Renderer::Property::BLEND_MODE, BlendMode::ON);
 214       renderer.SetProperty(Dali::Renderer::Property::DEPTH_INDEX, DepthIndex::CONTENT);
 215
 216       actor = Actor::New();
 217       actor.SetProperty(Dali::Actor::Property::NAME, "TextBackgroundColorActor");
 218       actor.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_LEFT);
 219       actor.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_LEFT);
 220       actor.SetProperty(Actor::Property::SIZE, textSize);
 221       actor.SetProperty(Actor::Property::COLOR_MODE, USE_OWN_MULTIPLY_PARENT_COLOR);
 222       actor.AddRenderer(renderer);
 223     }
 224   }
 225
 226   return actor;
 227 }
 228
 229 } // namespace Dali::Toolkit::Text