Optimize UITextEdit rendering

src/framework/graphics/ogl/painterogl1.cpp

@@ -135,6 +135,12 @@ void PainterOGL1::drawCoords(CoordsBuffer& coordsBuffer, DrawMode drawMode)
 #endif
 }
 
+void PainterOGL1::drawFillCoords(CoordsBuffer& coordsBuffer)
+{
+    setTexture(nullptr);
+    drawCoords(coordsBuffer);
+}
+
 void PainterOGL1::drawTextureCoords(CoordsBuffer& coordsBuffer, const TexturePtr& texture)
 {
     if(texture->isEmpty())

src/framework/graphics/ogl/painterogl1.h

@@ -50,6 +50,7 @@ public:
     void refreshState();
 
     void drawCoords(CoordsBuffer& coordsBuffer, DrawMode drawMode = Triangles);
+    void drawFillCoords(CoordsBuffer& coordsBuffer);
     void drawTextureCoords(CoordsBuffer& coordsBuffer, const TexturePtr& texture);
     void drawTexturedRect(const Rect& dest, const TexturePtr& texture, const Rect& src);
     void drawUpsideDownTexturedRect(const Rect& dest, const TexturePtr& texture, const Rect& src);

src/framework/graphics/ogl/painterogl2.cpp

@@ -120,6 +120,13 @@ void PainterOGL2::drawCoords(CoordsBuffer& coordsBuffer, DrawMode drawMode)
         PainterShaderProgram::enableAttributeArray(PainterShaderProgram::TEXCOORD_ATTR);
 }
 
+void PainterOGL2::drawFillCoords(CoordsBuffer& coordsBuffer)
+{
+    setDrawProgram(m_shaderProgram ? m_shaderProgram : m_drawSolidColorProgram.get());
+    setTexture(nullptr);
+    drawCoords(coordsBuffer);
+}
+
 void PainterOGL2::drawTextureCoords(CoordsBuffer& coordsBuffer, const TexturePtr& texture)
 {
     if(texture && texture->isEmpty())

src/framework/graphics/ogl/painterogl2.h

@@ -41,6 +41,7 @@ public:
     void unbind();
 
     void drawCoords(CoordsBuffer& coordsBuffer, DrawMode drawMode = Triangles);
+    void drawFillCoords(CoordsBuffer& coordsBuffer);
     void drawTextureCoords(CoordsBuffer& coordsBuffer, const TexturePtr& texture);
     void drawTexturedRect(const Rect& dest, const TexturePtr& texture, const Rect& src);
     void drawUpsideDownTexturedRect(const Rect& dest, const TexturePtr& texture, const Rect& src);

src/framework/graphics/painter.h

@@ -62,6 +62,7 @@ public:
     virtual void clear(const Color& color) = 0;
 
     virtual void drawCoords(CoordsBuffer& coordsBuffer, DrawMode drawMode = Triangles) = 0;
+    virtual void drawFillCoords(CoordsBuffer& coordsBuffer) = 0;
     virtual void drawTextureCoords(CoordsBuffer& coordsBuffer, const TexturePtr& texture) = 0;
     virtual void drawTexturedRect(const Rect& dest, const TexturePtr& texture, const Rect& src) = 0;
     void drawTexturedRect(const Rect& dest, const TexturePtr& texture) { drawTexturedRect(dest, texture, Rect(Point(0,0), texture->getSize())); }

src/framework/ui/uitextedit.cpp

@@ -49,6 +49,9 @@ UITextEdit::UITextEdit()
     m_updatesEnabled = true;
     m_selectionColor = Color::white;
     m_selectionBackgroundColor = Color::black;
+    m_glyphsTextCoordsBuffer.enableHardwareCaching();
+    m_glyphsSelectCoordsBuffer.enableHardwareCaching();
+    m_glyphsMustRecache = true;
     blinkCursor();
 }
 
@@ -62,38 +65,36 @@ void UITextEdit::drawSelf(Fw::DrawPane drawPane)
     drawImage(m_rect);
     drawIcon(m_rect);
 
-    //TODO: text rendering could be much optimized by using vertex buffer or caching the render into a texture
-
     int textLength = m_text.length();
     const TexturePtr& texture = m_font->getTexture();
     if(!texture)
         return;
 
-    if(hasSelection()) {
-        if(m_color != Color::alpha) {
-            g_painter->setColor(m_color);
-            for(int i=0;i<m_selectionStart;++i)
-                g_painter->drawTexturedRect(m_glyphsCoords[i], texture, m_glyphsTexCoords[i]);
-        }
+    bool glyphsMustRecache = m_glyphsMustRecache;
+    if(glyphsMustRecache)
+        m_glyphsMustRecache = false;
 
-        for(int i=m_selectionStart;i<m_selectionEnd;++i) {
-            g_painter->setColor(m_selectionBackgroundColor);
-            g_painter->drawFilledRect(m_glyphsCoords[i]);
-            g_painter->setColor(m_selectionColor);
-            g_painter->drawTexturedRect(m_glyphsCoords[i], texture, m_glyphsTexCoords[i]);
+    if(m_color != Color::alpha) {
+        if(glyphsMustRecache) {
+            m_glyphsTextCoordsBuffer.clear();
+            for(int i=0;i<textLength;++i)
+                m_glyphsTextCoordsBuffer.addRect(m_glyphsCoords[i], m_glyphsTexCoords[i]);
         }
-
-        if(m_color != Color::alpha) {
-            g_painter->setColor(m_color);
-            for(int i=m_selectionEnd;i<textLength;++i)
-                g_painter->drawTexturedRect(m_glyphsCoords[i], texture, m_glyphsTexCoords[i]);
-        }
-    } else if(m_color != Color::alpha) {
         g_painter->setColor(m_color);
-        for(int i=0;i<textLength;++i)
-            g_painter->drawTexturedRect(m_glyphsCoords[i], texture, m_glyphsTexCoords[i]);
+        g_painter->drawTextureCoords(m_glyphsTextCoordsBuffer, texture);
     }
 
+    if(hasSelection()) {
+        if(glyphsMustRecache) {
+            m_glyphsSelectCoordsBuffer.clear();
+            for(int i=m_selectionStart;i<m_selectionEnd;++i)
+                m_glyphsSelectCoordsBuffer.addRect(m_glyphsCoords[i], m_glyphsTexCoords[i]);
+        }
+        g_painter->setColor(m_selectionBackgroundColor);
+        g_painter->drawFillCoords(m_glyphsSelectCoordsBuffer);
+        g_painter->setColor(m_selectionColor);
+        g_painter->drawTextureCoords(m_glyphsSelectCoordsBuffer, texture);
+    }
 
     // render cursor
     if(isExplicitlyEnabled() && m_cursorVisible && m_cursorInRange && isActive() && m_cursorPos >= 0) {
@@ -136,6 +137,9 @@ void UITextEdit::update(bool focusCursor)
     if(m_rect.isEmpty())
         return;
 
+    // recache coords buffers
+    recacheGlyphs();
+
     // map glyphs positions
     Size textBoxSize;
     const std::vector<Point>& glyphsPositions = m_font->calculateGlyphsPositions(text, m_textAlign, &textBoxSize);
@@ -360,6 +364,7 @@ void UITextEdit::setSelection(int start, int end)
 
     m_selectionStart = stdext::clamp<int>(start, 0, (int)m_text.length());
     m_selectionEnd = stdext::clamp<int>(end, 0, (int)m_text.length());
+    recacheGlyphs();
 }
 
 void UITextEdit::setTextHidden(bool hidden)

src/framework/ui/uitextedit.h

@@ -108,6 +108,7 @@ protected:
 private:
     void disableUpdates() { m_updatesEnabled = false; }
     void enableUpdates() { m_updatesEnabled = true; }
+    void recacheGlyphs() { m_glyphsMustRecache = true; }
 
     Rect m_drawArea;
     int m_cursorPos;
@@ -137,6 +138,10 @@ private:
 
     std::vector<Rect> m_glyphsCoords;
     std::vector<Rect> m_glyphsTexCoords;
+
+    CoordsBuffer m_glyphsTextCoordsBuffer;
+    CoordsBuffer m_glyphsSelectCoordsBuffer;
+    bool m_glyphsMustRecache;
 };
 
 #endif