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#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 =newQOpenGLContext;
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());
staticconstchar*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";
staticconstchar*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 =newQOpenGLShaderProgram;
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 =newQOpenGLVertexArrayObject;
m_vao->create();
QOpenGLVertexArrayObject::Binder vaoBinder(m_vao);
m_vbo =newQOpenGLBuffer;
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
};
constint 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,
(constvoid*)(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);
}
