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无法在绘制元素后绘制数组

indexing opengl qt c++

birgersp · 技术社区 · 10 年前

我画了一个巨大的彩色表面(超过130万个指数)。该曲面使用“彩色顶点”进行索引。每当我尝试在缓冲三角形(有色顶点)之后绘制非缓冲三角形时,非缓冲三角形不会出现。

如果我跳过绘制曲面(缓冲三角形),则非缓冲三角形将按应有方式绘制。

绘制缓冲顶点:

// Bind array buffer
arrayBuffer->bind();

// Set position of vertices
int posLocation = program->attributeLocation("a_position");
program->enableAttributeArray(posLocation);
program->setAttributeBuffer(posLocation, GL_FLOAT, 0, 3, sizeof(ColoredVertex));

// Set color of vertices
int colorLocation = program->attributeLocation("a_color");
program->enableAttributeArray(colorLocation);
program->setAttributeBuffer(colorLocation, GL_FLOAT, sizeof(QVector3D), 3, sizeof(ColoredVertex));
(GLfloat) 0.0);

// Bind index buffer and draw triangles
indexBuffer->bind();
glDrawElements(GL_TRIANGLES, indicesCount(), GL_UNSIGNED_INT, 0);

绘制非缓冲顶点(面):

if (faces.size() == 0) {
    qDebug("Tried to draw a textured block with no faces.");
    return;
}

int posLocation = program->attributeLocation("a_position");
int texcoordLocation = program->attributeLocation("a_texcoord");

// Draw faces
QHashIterator<Block::Side, Face> iterator(faces);
while (iterator.hasNext()) {
    Face face = iterator.next().value();

    program->setAttributeArray(posLocation, face.coordinates.constData());
    program->enableAttributeArray(posLocation);

    program->setAttributeArray(texcoordLocation, face.textureCoordinates.constData());
    program->enableAttributeArray(texcoordLocation);

    glDrawArrays(GL_LINES, 0, 6);
}

1 回复 | 直到 10 年前

birgersp 10 年前

该错误似乎是由于未禁用属性数组并正确释放缓冲区对象所致。以下代码正常工作。

绘制缓冲顶点:

// Bind array buffer
arrayBuffer->bind();

int posLocation = program->attributeLocation("a_position");
int colorLocation = program->attributeLocation("a_color");

program->enableAttributeArray("a_position");
program->enableAttributeArray("a_color");

program->setAttributeBuffer(posLocation, GL_FLOAT, 0, 3, sizeof(ColoredVertex));
program->setAttributeBuffer(colorLocation, GL_FLOAT, sizeof(QVector3D), 3, sizeof(ColoredVertex));

// Bind index buffer and draw triangles
indexBuffer->bind();
glDrawElements(GL_TRIANGLES, indicesCount(), GL_UNSIGNED_INT, 0);
indexBuffer->release();

program->disableAttributeArray(posLocation);
program->disableAttributeArray(colorLocation);

arrayBuffer->release();

绘制非缓冲顶点(面):

if (faces.size() == 0) {
    qDebug("Tried to draw a textured block with no faces.");
    return;
}

int posLocation = program->attributeLocation("a_position");
int texcoordLocation = program->attributeLocation("a_texcoord");

program->enableAttributeArray(posLocation);
program->enableAttributeArray(posLocation);

program->enableAttributeArray(texcoordLocation);
program->enableAttributeArray(texcoordLocation);

// Draw faces
QHashIterator<Block::Side, Face> iterator(faces);
while (iterator.hasNext()) {
    Face face = iterator.next().value();

    program->setAttributeArray(posLocation, face.coordinates.constData());
    program->setAttributeArray(texcoordLocation, face.textureCoordinates.constData());

    glDrawArrays(GL_TRIANGLES, 0, face.coordinates.size());
}

program->disableAttributeArray(posLocation);
program->disableAttributeArray(texcoordLocation);