C++ QOpenGLShaderProgram::disableAttributeArray方法代码示例

    void exposeEvent(QExposeEvent *)
    {
        if (!isExposed())
            return;

        if (!gl) {
            gl = new QOpenGLContext();
            gl->setFormat(requestedFormat());
            gl->create();
        }

        gl->makeCurrent(this);

        QOpenGLShaderProgram prog;
        prog.addShaderFromSourceCode(QOpenGLShader::Vertex,
                                     "attribute highp vec4 a_Pos;"
                                     "attribute lowp vec4 a_Color;"
                                     "varying lowp vec4 v_Color;"
                                     "void main() {"
                                     "    gl_Position = a_Pos;"
                                     "    v_Color = a_Color;"
                                     "}");
        prog.addShaderFromSourceCode(QOpenGLShader::Fragment,
                                     "varying lowp vec4 v_Color;"
                                     "void main() {"
                                     "    gl_FragColor = v_Color;"
                                     "}");
        prog.bind();

        glClearColor(0, 0, 0, 1);
        glClear(GL_COLOR_BUFFER_BIT);
        glViewport(0, 0, width(), height());

        prog.enableAttributeArray("a_Pos");
        prog.enableAttributeArray("a_Color");

        float coords[] = { -0.7f,  0.7f,
                           0.8f,  0.8f,
                           -0.8f, -0.8f,
                           0.7f, -0.7f
                         };
        float colors[] = { 1, 0, 0, 1,
                           0, 1, 0, 1,
                           0, 0, 1, 1,
                           0, 0, 0, 0
                         };

        prog.setAttributeArray("a_Pos", GL_FLOAT, coords, 2, 0);
        prog.setAttributeArray("a_Color", GL_FLOAT, colors, 4, 0);

        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        prog.disableAttributeArray("a_Pos");
        prog.disableAttributeArray("a_Color");

        gl->swapBuffers(this);
    }

/******************************************************************************
* Renders a 2d polyline in the viewport.
******************************************************************************/
void ViewportSceneRenderer::render2DPolyline(const Point2* points, int count, const ColorA& color, bool closed)
{
	OVITO_STATIC_ASSERT(sizeof(points[0]) == 2*sizeof(GLfloat));

	// Load OpenGL shader.
	QOpenGLShaderProgram* shader = loadShaderProgram("line", ":/core/glsl/lines/line.vs", ":/core/glsl/lines/line.fs");
	if(!shader->bind())
		throw Exception(tr("Failed to bind OpenGL shader."));

	bool wasDepthTestEnabled = glIsEnabled(GL_DEPTH_TEST);
	glDisable(GL_DEPTH_TEST);

	GLint vc[4];
	glGetIntegerv(GL_VIEWPORT, vc);
	QMatrix4x4 tm;
	tm.ortho(vc[0], vc[0] + vc[2], vc[1] + vc[3], vc[1], -1, 1);
	OVITO_CHECK_OPENGL(shader->setUniformValue("modelview_projection_matrix", tm));

	QOpenGLBuffer vertexBuffer;
	if(glformat().majorVersion() >= 3) {
		if(!vertexBuffer.create())
			throw Exception(tr("Failed to create OpenGL vertex buffer."));
		if(!vertexBuffer.bind())
				throw Exception(tr("Failed to bind OpenGL vertex buffer."));
		vertexBuffer.allocate(points, 2 * sizeof(GLfloat) * count);
		OVITO_CHECK_OPENGL(shader->enableAttributeArray("position"));
		OVITO_CHECK_OPENGL(shader->setAttributeBuffer("position", GL_FLOAT, 0, 2));
		vertexBuffer.release();
	}
	else {
		OVITO_CHECK_OPENGL(glEnableClientState(GL_VERTEX_ARRAY));
		OVITO_CHECK_OPENGL(glVertexPointer(2, GL_FLOAT, 0, points));
	}

	if(glformat().majorVersion() >= 3) {
		OVITO_CHECK_OPENGL(shader->disableAttributeArray("color"));
		OVITO_CHECK_OPENGL(shader->setAttributeValue("color", color.r(), color.g(), color.b(), color.a()));
	}
	else {
		OVITO_CHECK_OPENGL(glColor4(color));
	}

	OVITO_CHECK_OPENGL(glDrawArrays(closed ? GL_LINE_LOOP : GL_LINE_STRIP, 0, count));

	if(glformat().majorVersion() >= 3) {
		shader->disableAttributeArray("position");
	}
	else {
		OVITO_CHECK_OPENGL(glDisableClientState(GL_VERTEX_ARRAY));
	}
	shader->release();
	if(wasDepthTestEnabled) glEnable(GL_DEPTH_TEST);
}

void Painter::renderScene(const Camera &camera)
{
    m_envMap->paint(camera);

    /* Paint gems */
    QOpenGLShaderProgram *gemProgram = (*m_shaderPrograms)[ShaderPrograms::GemProgram];
    gemProgram->bind();

    gemProgram->enableAttributeArray(0);
    gemProgram->enableAttributeArray(1);

    gemProgram->setUniformValue("envmap", 0);
    gemProgram->setUniformValue("gemStructureMap", 1);
    gemProgram->setUniformValue("rainbowMap", 2);
    gemProgram->setUniformValue("eye", camera.eye());
    gemProgram->setUniformValue("viewProjection", camera.viewProjection());
    m_gl->glActiveTexture(GL_TEXTURE0);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, m_envMap->cubeMapTexture());
    m_gl->glActiveTexture(GL_TEXTURE1);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, m_gemStructureMap->cubeMapTexture());
    m_gl->glActiveTexture(GL_TEXTURE2);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, m_rainbowMap->cubeMapTexture());

    QHash<ShaderPrograms, QOpenGLShaderProgram*> shaderPrograms;
    shaderPrograms.insert(ShaderPrograms::GemProgram, m_shaderPrograms->value(ShaderPrograms::GemProgram));
    shaderPrograms.insert(ShaderPrograms::LighRayProgram, m_shaderPrograms->value(ShaderPrograms::LighRayProgram));

    m_sceneRenderer->paint(*m_gl, camera.viewProjection(), shaderPrograms);

    m_gl->glActiveTexture(GL_TEXTURE0);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
    m_gl->glActiveTexture(GL_TEXTURE1);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
    m_gl->glActiveTexture(GL_TEXTURE2);
    m_gl->glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
    m_gl->glBindTexture(GL_TEXTURE_2D, 0);

    gemProgram->disableAttributeArray(0);
    gemProgram->disableAttributeArray(1);

    gemProgram->release();
}

void csSurface::draw(QOpenGLShaderProgram& program)
{
  if( _initRequired ) {
    initialize();
  }

  if( _meshInfo.isEmpty() ) {
    return;
  }

  glDisable(GL_CULL_FACE);

  program.setUniformValue("cs_Model", _model);
  program.setUniformValue("cs_zMin", _meshInfo.zMin());
  program.setUniformValue("cs_zInterval", _meshInfo.zInterval());
  program.setUniformValue("cs_ColorMap", TMU_COLORMAP);

  _surface->bind();
  const int vertexLoc = program.attributeLocation("cs_Vertex");
  program.enableAttributeArray(vertexLoc);
  program.setAttributeBuffer(vertexLoc, GL_FLOAT, 0, 3);

  _colorTexture->bind(TMU_COLORMAP, QOpenGLTexture::ResetTextureUnit);

  _strip->bind();
  const int numStrips       =   _meshInfo.rowCount()   -1;
  const int numVertPerStrip = 2*_meshInfo.columnCount();
  for(int y = 0; y < numStrips; y++) {
    const GLuint  offset  = sizeof(GLuint)*y*numVertPerStrip;
    const GLvoid *indices = (GLvoid*)offset;
    glDrawElements(GL_TRIANGLE_STRIP, numVertPerStrip, GL_UNSIGNED_INT, indices);
  }
  _strip->release();

  _colorTexture->release();

  program.disableAttributeArray(vertexLoc);
  _surface->release();
}

void csSurface::drawMesh(QOpenGLShaderProgram& program)
{
  if( _initRequired ) {
    initialize();
  }

  if( _meshInfo.isEmpty() ) {
    return;
  }

  program.setUniformValue("cs_DepthOffset", csCoordinateBox::DepthOffset);
  program.setUniformValue("cs_Model", _model);

  _surface->bind();
  const int vertexLoc = program.attributeLocation("cs_Vertex");
  program.enableAttributeArray(vertexLoc);
  program.setAttributeBuffer(vertexLoc, GL_FLOAT, 0, 3);

  const int colorLoc = program.attributeLocation("cs_Color");
  program.setAttributeValue(colorLoc, QColor(Qt::black));

  // Along x-Axis
  for(int y = 0; y < _meshInfo.rowCount(); y++) {
    glDrawArrays(GL_LINE_STRIP,
                 y*_meshInfo.columnCount(), _meshInfo.columnCount());
  }

  // Along y-Axis
  _meshY->bind();
  for(int x = 0; x < _meshInfo.columnCount(); x++) {
    const GLuint  offset  = sizeof(GLuint)*x*_meshInfo.rowCount();
    const GLvoid *indices = (GLvoid*)offset;
    glDrawElements(GL_LINE_STRIP, _meshInfo.rowCount(), GL_UNSIGNED_INT, indices);
  }
  _meshY->release();

  program.disableAttributeArray(vertexLoc);
  _surface->release();
}

//.........这里部分代码省略.........
        glGenTextures(1,&textureId);
        glBindTexture(GL_TEXTURE_2D, textureId);
        glTexImage2D(GL_TEXTURE_2D,0, GL_RGB, res.width(), res.height(), 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    }

    if (currFrame.isValid())
    {
        pboIndex = (pboIndex + 1) % 2;
        int nextPboIndex = (pboIndex + 1) % 2;

        if (pboAllocSize != currFrame.frameData.size())
        {
            qDebug() << "VideoSurface: Resize pbo " << currFrame.frameData.size() << "(" << currFrame.resolution << ")" << "bytes (before" << pboAllocSize << ")";

            pbo[0]->bind();
            pbo[0]->allocate(currFrame.frameData.size());
            pbo[0]->release();

            pbo[1]->bind();
            pbo[1]->allocate(currFrame.frameData.size());
            pbo[1]->release();

            pboAllocSize = currFrame.frameData.size();
        }


        pbo[pboIndex]->bind();
        glBindTexture(GL_TEXTURE_2D, textureId);
        glTexSubImage2D(GL_TEXTURE_2D,0,0,0, res.width(), res.height(), GL_RGB, GL_UNSIGNED_BYTE, 0);
        pbo[pboIndex]->unmap();
        pbo[pboIndex]->release();

        // transfer data
        pbo[nextPboIndex]->bind();
        void* ptr = pbo[nextPboIndex]->map(QOpenGLBuffer::WriteOnly);
        if (ptr)
            memcpy(ptr, currFrame.frameData.data(), currFrame.frameData.size());
        pbo[nextPboIndex]->unmap();
        pbo[nextPboIndex]->release();
    }

    // background
    glClearColor(0, 0, 0, 1);
    glClear(GL_COLOR_BUFFER_BIT);

    // keep aspect ratio
    float aspectRatio = float(res.width()) / float(res.height());
    if (width() < float(height()) * aspectRatio)
    {
        float h = float(width()) / aspectRatio;
        glViewport(0, (height() - h)*0.5f, width(), h);
    }
    else
    {
        float w = float(height()) * float(aspectRatio);
        glViewport((width() - w)*0.5f, 0, w, height());
    }

    QOpenGLShaderProgram* programm = nullptr;
    switch (frame.format)
    {
    case VideoFrame::YUV:
        programm = yuvProgramm;
        break;
    case VideoFrame::BGR:
        programm = bgrProgramm;
        break;
    default:
        break;
    }

    if (programm)
    {
        // render pbo
        static float values[] = {
            -1, -1,
            1, -1,
            -1, 1,
            1, 1
        };

        programm->bind();
        programm->setAttributeArray(0, GL_FLOAT, values, 2);
        programm->enableAttributeArray(0);
    }

    glBindTexture(GL_TEXTURE_2D, textureId);

    //draw fullscreen quad
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

    glBindTexture(GL_TEXTURE_2D, 0);

    if (programm)
    {
        programm->disableAttributeArray(0);
        programm->release();
    }
}