cuberenderer.cpp Example File
rendercontrol/cuberenderer.cpp/**************************************************************************** ** ** Copyright (C) 2017 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. 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IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "cuberenderer.h" #include <QOpenGLContext> #include <QOpenGLFunctions> #include <QOpenGLShaderProgram> #include <QOpenGLVertexArrayObject> #include <QOpenGLBuffer> #include <QOpenGLVertexArrayObject> #include <QOffscreenSurface> #include <QWindow> CubeRenderer::CubeRenderer(QOffscreenSurface *offscreenSurface) : m_offscreenSurface(offscreenSurface), m_context(nullptr), m_program(nullptr), m_vbo(nullptr), m_vao(nullptr), m_matrixLoc(0) { } CubeRenderer::~CubeRenderer() { // Use a temporary offscreen surface to do the cleanup. // There may not be a native window surface available anymore at this stage. m_context->makeCurrent(m_offscreenSurface); delete m_program; delete m_vbo; delete m_vao; m_context->doneCurrent(); delete m_context; } void CubeRenderer::init(QWindow *w, QOpenGLContext *share) { m_context = new QOpenGLContext; m_context->setShareContext(share); m_context->setFormat(w->requestedFormat()); m_context->create(); if (!m_context->makeCurrent(w)) return; QOpenGLFunctions *f = m_context->functions(); f->glClearColor(0.0f, 0.1f, 0.25f, 1.0f); f->glViewport(0, 0, w->width() * w->devicePixelRatio(), w->height() * w->devicePixelRatio()); static const char *vertexShaderSource = "attribute highp vec4 vertex;\n" "attribute lowp vec2 coord;\n" "varying lowp vec2 v_coord;\n" "uniform highp mat4 matrix;\n" "void main() {\n" " v_coord = coord;\n" " gl_Position = matrix * vertex;\n" "}\n"; static const char *fragmentShaderSource = "varying lowp vec2 v_coord;\n" "uniform sampler2D sampler;\n" "void main() {\n" " gl_FragColor = vec4(texture2D(sampler, v_coord).rgb, 1.0);\n" "}\n"; m_program = new QOpenGLShaderProgram; m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Vertex, vertexShaderSource); m_program->addCacheableShaderFromSourceCode(QOpenGLShader::Fragment, fragmentShaderSource); m_program->bindAttributeLocation("vertex", 0); m_program->bindAttributeLocation("coord", 1); m_program->link(); m_matrixLoc = m_program->uniformLocation("matrix"); m_vao = new QOpenGLVertexArrayObject; m_vao->create(); QOpenGLVertexArrayObject::Binder vaoBinder(m_vao); m_vbo = new QOpenGLBuffer; m_vbo->create(); m_vbo->bind(); GLfloat v[] = { -0.5, 0.5, 0.5, 0.5,-0.5,0.5,-0.5,-0.5,0.5, 0.5, -0.5, 0.5, -0.5,0.5,0.5,0.5,0.5,0.5, -0.5, -0.5, -0.5, 0.5,-0.5,-0.5,-0.5,0.5,-0.5, 0.5, 0.5, -0.5, -0.5,0.5,-0.5,0.5,-0.5,-0.5, 0.5, -0.5, -0.5, 0.5,-0.5,0.5,0.5,0.5,-0.5, 0.5, 0.5, 0.5, 0.5,0.5,-0.5,0.5,-0.5,0.5, -0.5, 0.5, -0.5, -0.5,-0.5,0.5,-0.5,-0.5,-0.5, -0.5, -0.5, 0.5, -0.5,0.5,-0.5,-0.5,0.5,0.5, 0.5, 0.5, -0.5, -0.5, 0.5, 0.5, -0.5, 0.5, -0.5, -0.5, 0.5, 0.5, 0.5, 0.5, -0.5, 0.5, 0.5, 0.5, -0.5, -0.5, -0.5, -0.5, -0.5, 0.5, 0.5, -0.5, -0.5, 0.5, -0.5, 0.5, 0.5, -0.5, -0.5, -0.5, -0.5, 0.5 }; GLfloat texCoords[] = { 0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, 1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f, 0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, 0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f, 1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f, 1.0f,1.0f }; const int vertexCount = 36; m_vbo->allocate(sizeof(GLfloat) * vertexCount * 5); m_vbo->write(0, v, sizeof(GLfloat) * vertexCount * 3); m_vbo->write(sizeof(GLfloat) * vertexCount * 3, texCoords, sizeof(GLfloat) * vertexCount * 2); m_vbo->release(); if (m_vao->isCreated()) setupVertexAttribs(); } void CubeRenderer::resize(int w, int h) { m_proj.setToIdentity(); m_proj.perspective(45, w / float(h), 0.01f, 100.0f); } void CubeRenderer::setupVertexAttribs() { m_vbo->bind(); m_program->enableAttributeArray(0); m_program->enableAttributeArray(1); m_context->functions()->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nullptr); m_context->functions()->glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, (const void *)(36 * 3 * sizeof(GLfloat))); m_vbo->release(); } void CubeRenderer::render(QWindow *w, QOpenGLContext *share, uint texture) { if (!m_context) init(w, share); if (!m_context->makeCurrent(w)) return; QOpenGLFunctions *f = m_context->functions(); f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); if (texture) { f->glBindTexture(GL_TEXTURE_2D, texture); f->glFrontFace(GL_CW); // because our cube's vertex data is such f->glEnable(GL_CULL_FACE); f->glEnable(GL_DEPTH_TEST); m_program->bind(); QOpenGLVertexArrayObject::Binder vaoBinder(m_vao); // If VAOs are not supported, set the vertex attributes every time. if (!m_vao->isCreated()) setupVertexAttribs(); static GLfloat angle = 0; QMatrix4x4 m; m.translate(0, 0, -2); m.rotate(90, 0, 0, 1); m.rotate(angle, 0.5, 1, 0); angle += 0.5f; m_program->setUniformValue(m_matrixLoc, m_proj * m); // Draw the cube. f->glDrawArrays(GL_TRIANGLES, 0, 36); } m_context->swapBuffers(w); }