Databases
StackOverflow2013
Postsdbo
POGLKit: [drawing pixels] initializing GLfloat array
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POGLKit: [drawing pixels] initializing GLfloat array
    primarykey
    data
    text
    <p>I am drawing a pixel using GLKit. I can successfully draw the pixel at (10, 10) coordinates if I have:</p> <pre><code>glClearColor(0.65f, 0.65f, 0.65f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Prepare the effect for rendering [self.effect prepareToDraw]; GLfloat points[] = { 10.0f, 10.0f, }; glClearColor(1.0f, 1.0f, 0.0f, 1.0f); GLuint bufferObjectNameArray; glGenBuffers(1, &amp;bufferObjectNameArray); glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNameArray); glBufferData( GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW); glEnableVertexAttribArray(GLKVertexAttribPosition); glVertexAttribPointer( GLKVertexAttribPosition, 2, GL_FLOAT, GL_FALSE, 2*4, NULL); glDrawArrays(GL_POINTS, 0, 1); </code></pre> <p>But I want to decide at runtime how many and exactly where I want to draw pixels, so I tried this but it is drawing pixel at (10, 0), something's wrong here:</p> <pre><code>glClearColor(0.65f, 0.65f, 0.65f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Prepare the effect for rendering [self.effect prepareToDraw]; GLfloat *points = (GLfloat*)malloc(sizeof(GLfloat) * 2); for (int i=0; i&lt;2; i++) { points[i] = 10.0f; } glClearColor(1.0f, 1.0f, 0.0f, 1.0f); GLuint bufferObjectNameArray; glGenBuffers(1, &amp;bufferObjectNameArray); glBindBuffer(GL_ARRAY_BUFFER, bufferObjectNameArray); glBufferData( GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW); glEnableVertexAttribArray(GLKVertexAttribPosition); glVertexAttribPointer( GLKVertexAttribPosition, 2, GL_FLOAT, GL_FALSE, 2*4, NULL); glDrawArrays(GL_POINTS, 0, 1); </code></pre> <p>Kindly help me out.</p> <p>Edit: <strong>Problem</strong> Actually the problem is: I can't figure out what is the difference between:</p> <pre><code>GLfloat points[] = { 10.0f, 10.0f, }; </code></pre> <p>AND</p> <pre><code>GLfloat *points = (GLfloat*)malloc(sizeof(GLfloat) * 2); for (int i=0; i&lt;2; i++) { points[i] = 10.0f; } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAsymptote
    1. USAsymptote
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POGLKit: [drawing pixels] initializing GLfloat array
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

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