Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>In this code</p> <pre><code>void drawLines() { glBegin(GL_LINES); glColor3f(1.0,0.0,0.0); for(int i=0;i&lt;z;i++) { glVertex2f(arr[i][0],arr[i][1]); } glEnd(); } </code></pre> <p><code>GL_LINES</code> is a drawing mode where two consecutive vertices make a line segment. Then the next two and so so. What you're drawing is a <em>line strip</em>; replacing <code>GL_LINES</code> with <code>GL_LINE_STRIP</code> will give you your expected result.</p> <p>On a side note: You should abandon using immediate mode (glBegin, glVertex, glEnd). It's slow, it's cumbersome to work with and in the long term can become a major PITA. Use at least vertex arrays; they've been the recommended way of supplying geometry data for well over 15 years. Plus it makes your code much simpler. Your code above can be replaced with this:</p> <pre><code>/* vertex data comes from an array */ glEnableClientState(GL_VERTEX_ARRAY); /* we want to use a common color for all vertices */ glDisableClientState(GL_COLOR_ARRAY); glColor3f(1.0, 0.0, 0.0); /* where to get the data from */ glVertexPointer(2, GL_DOUBLE, sizeof(double)*4, arr); /* draw the whole thing */ glDrawArrays(GL_LINE_STRIP, 0, z); /* cleanup */ glDisableClientState(GL_VERTEX_ARRAY); </code></pre> <p>As you can see it's shorter, more concise, easier to read and it avoids doing <code>z+3</code> function calls, each of which taking some time to execute.</p> <p><strong>Important</strong> that OpenGL can digest that multidimensional array <code>arr</code> is due to the fact, that statically allocated storage of multidimensional arrays is always contiguous. It would not work if you'd allocate an array of pointers to arrays (the naive way to allocate multidimensional arrays dynamically).</p>
    singulars
    1. This table or related slice is empty.
    1. POContinuous Line On Mouse Drag
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USdatenwolf
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POContinuous Line On Mouse Drag
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThanks For the Answer and a very good info about using vertex arrays.. This works like charm
      singulars
      1. PO
      1. USadil
    2. COI Have one more question. when I Used the exe of above code on my friends pc then instead of a circular point there was a squared box traversing the path. What could be the reason for this?
      singulars
      1. PO
      1. USadil
    3. CO@adil: Usually you get square points of point smoothing is disabled and round points with point smoothing enables. I don't see your program enabling point smoothing. However implementations have some leeway how they interpret points (I recommend reading the specification on the topic) and your friend may have antialiasing enabled in the driver, which makes the point appear round.
      singulars
      1. PO
      1. USdatenwolf
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload