Optimise VAO usage

sdrgui/gui/glshadercolors.cpp

@@ -27,6 +27,9 @@
 
 GLShaderColors::GLShaderColors() :
 	m_program(nullptr),
+    m_vao(nullptr),
+    m_verticesBuf(nullptr),
+    m_colorBuf(nullptr),
     m_matrixLoc(0),
     m_alphaLoc(0)
 { }
@@ -48,6 +51,10 @@ void GLShaderColors::initializeGL(int majorVersion, int minorVersion)
         if (!m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, m_fragmentShaderSourceColored)) {
             qDebug() << "GLShaderColors::initializeGL: error in fragment shader: " << m_program->log();
         }
+
+        m_vao = new QOpenGLVertexArrayObject();
+        m_vao->create();
+        m_vao->bind();
     }
     else
     {
@@ -69,6 +76,16 @@ void GLShaderColors::initializeGL(int majorVersion, int minorVersion)
 	m_program->bind();
 	m_matrixLoc = m_program->uniformLocation("uMatrix");
     m_alphaLoc = m_program->uniformLocation("uAlpha");
+    if (m_vao)
+    {
+        m_verticesBuf = new QOpenGLBuffer(QOpenGLBuffer::VertexBuffer);
+        m_verticesBuf->setUsagePattern(QOpenGLBuffer::DynamicDraw);
+        m_verticesBuf->create();
+        m_colorBuf = new QOpenGLBuffer(QOpenGLBuffer::VertexBuffer);
+        m_colorBuf->setUsagePattern(QOpenGLBuffer::DynamicDraw);
+        m_colorBuf->create();
+        m_vao->release();
+    }
 	m_program->release();
 }
 
@@ -106,27 +123,50 @@ void GLShaderColors::draw(unsigned int mode, const QMatrix4x4& transformMatrix,
 	f->glEnable(GL_BLEND);
 	f->glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	f->glLineWidth(1.0f);
-	f->glEnableVertexAttribArray(0); // vertex
+    if (m_vao)
-	f->glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, vertices);
+    {
-    f->glEnableVertexAttribArray(1); // colors
+        m_vao->bind();
-    f->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, colors);
+
+        m_verticesBuf->bind();
+        m_verticesBuf->allocate(vertices, nbVertices * 2 * sizeof(GL_FLOAT));
+        m_program->enableAttributeArray(0);
+        m_program->setAttributeBuffer(0, GL_FLOAT, 0, 2);
+
+        m_colorBuf->bind();
+        m_colorBuf->allocate(colors, nbVertices * 3 * sizeof(GL_FLOAT));
+        m_program->enableAttributeArray(1);
+        m_program->setAttributeBuffer(1, GL_FLOAT, 0, 3);
+    }
+    else
+    {
+        f->glEnableVertexAttribArray(0); // vertex
+        f->glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, vertices);
+        f->glEnableVertexAttribArray(1); // colors
+        f->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, colors);
+    }
 	f->glDrawArrays(mode, 0, nbVertices);
-	f->glDisableVertexAttribArray(0);
+    if (m_vao)
-    f->glDisableVertexAttribArray(1);
+    {
+        m_vao->release();
+    }
+    else
+    {
+        f->glDisableVertexAttribArray(0);
+        f->glDisableVertexAttribArray(1);
+    }
 	m_program->release();
 }
 
 void GLShaderColors::cleanup()
 {
-	if (!QOpenGLContext::currentContext()) {
+    delete m_program;
-		return;
+    m_program = nullptr;
-	}
+    delete m_vao;
-
+    m_vao = nullptr;
-	if (m_program)
+    delete m_verticesBuf;
-	{
+    m_verticesBuf = nullptr;
-		delete m_program;
+    delete m_colorBuf;
-		m_program = nullptr;
+    m_colorBuf = nullptr;
-	}
 }
 
 const QString GLShaderColors::m_vertexShaderSourceSimple2 = QString(

sdrgui/gui/glshadercolors.h

@@ -24,6 +24,8 @@
 
 #include <QString>
 #include <QOpenGLFunctions>
+#include <QOpenGLVertexArrayObject>
+#include <QOpenGLBuffer>
 
 #include "export.h"
 
@@ -49,6 +51,9 @@ private:
 	void draw(unsigned int mode, const QMatrix4x4& transformMatrix, GLfloat *vertices, GLfloat *colors, GLfloat alpha, int nbVertices);
 
 	QOpenGLShaderProgram *m_program;
+    QOpenGLVertexArrayObject *m_vao;
+    QOpenGLBuffer *m_verticesBuf;
+    QOpenGLBuffer *m_colorBuf;
 	int m_matrixLoc;
     int m_alphaLoc;
 	static const QString m_vertexShaderSourceSimple2;

sdrgui/gui/glshaderspectrogram.cpp

@@ -169,9 +169,20 @@ void GLShaderSpectrogram::initGrid(int elements)
     m_vertexBuf->bind();
     m_vertexBuf->allocate(&vertices[0], vertices.size() * sizeof(QVector2D));
 
-    // Create an array of indices into the vertex array that traces both horizontal and vertical lines
+    if (m_vao)
+    {
+        m_programShaded->enableAttributeArray(m_coord2dLoc);
+        m_programShaded->setAttributeBuffer(m_coord2dLoc, GL_FLOAT, 0, 2);
+        m_programSimple->enableAttributeArray(m_coord2dLoc);
+        m_programSimple->setAttributeBuffer(m_coord2dLoc, GL_FLOAT, 0, 2);
+        m_vao->release();
+    }
+
     std::vector<GLuint> indices(m_gridElements * m_gridElements * 6);
-    int i = 0;
+    int i;
+
+    // Create an array of indices into the vertex array that traces both horizontal and vertical lines
+    i = 0;
 
     for (int y = 0; y < e1; y++) {
         for (int x = 0; x < m_gridElements; x++) {
@@ -190,7 +201,7 @@ void GLShaderSpectrogram::initGrid(int elements)
     m_index0Buf->bind();
     m_index0Buf->allocate(&indices[0], m_gridElements * (e1) * 4 * sizeof(GLuint));
 
-    // Create another array of indices that describes all the triangles needed to create a completely filled surface
+    // Create an array of indices that describes all the triangles needed to create a completely filled surface
     i = 0;
 
     for (int y = 0; y < m_gridElements; y++) {
@@ -208,11 +219,7 @@ void GLShaderSpectrogram::initGrid(int elements)
     m_index1Buf->bind();
     m_index1Buf->allocate(&indices[0], indices.size() * sizeof(GLuint));
 
-    if (m_vao)
+    if (!m_vao)
-    {
-        m_vao->release();
-    }
-    else
     {
         QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
         f->glBindBuffer(GL_ARRAY_BUFFER, 0);
@@ -438,28 +445,23 @@ void GLShaderSpectrogram::drawSurface(SpectrumSettings::SpectrogramStyle style,
         program->setUniformValueArray(m_lightPosLoc, lightPos, 1, 3);
     }
 
-    if (m_vao) {
-        m_vao->bind();
-    }
-
     f->glEnable(GL_DEPTH_TEST);
 
     f->glPolygonOffset(1, 0);
     f->glEnable(GL_POLYGON_OFFSET_FILL);
 
-    m_vertexBuf->bind();
     if (m_vao)
     {
-        program->enableAttributeArray(m_coord2dLoc);
+        m_vao->bind();
-        program->setAttributeBuffer(m_coord2dLoc, GL_FLOAT, 0, 2);
     }
     else
     {
+        m_vertexBuf->bind();
         f->glEnableVertexAttribArray(m_coord2dLoc);
         f->glVertexAttribPointer(m_coord2dLoc, 2, GL_FLOAT, GL_FALSE, 0, 0);
     }
-
     m_index1Buf->bind();
+
     switch (style)
     {
     case SpectrumSettings::Points:
@@ -486,21 +488,14 @@ void GLShaderSpectrogram::drawSurface(SpectrumSettings::SpectrogramStyle style,
         f->glDrawElements(GL_LINES, m_gridElements * (m_gridElements+1) * 4, GL_UNSIGNED_INT, 0);
     }
 
-    if (m_vao) {
-        program->disableAttributeArray(m_coord2dLoc);
-    } else {
-        f->glDisableVertexAttribArray(m_coord2dLoc);
-    }
-
     if (m_vao)
     {
         m_vao->release();
-        m_vertexBuf->release();
         m_index0Buf->release();
-        m_index1Buf->release();
     }
     else
     {
+        f->glDisableVertexAttribArray(m_coord2dLoc);
         // Need to do this, otherwise nothing else is drawn by other shaders
         f->glBindBuffer(GL_ARRAY_BUFFER, 0);
         f->glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);