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POTrying to implement OpenGL brush
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  1. POTrying to implement OpenGL brush
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    copied!<p>I'm trying to implement OpenGL brush for mac os. Using GLPaint as sample. Main trouble is that GLPaint is iOS application, and I need it on mac os. Somehow i almost edited it to work on MAC OS (well at least i think so), but it's still not running. I guess, the main issue is in <em>'EAGLContext'</em> and <em>'NSOpenGLContext'</em> or maybe <em>'OpenGL'</em> and <em>'OpenGL ES'</em> differences. When I try to use <em>'renderLineFromPoint:ToPoint:</em>'</p> <ul> <li><code>[self renderLineFromPoint:vieta toPoint:buvusVieta];</code></li> </ul> <p>it shows me error at </p> <ul> <li>`glBindFramebuffer(GL_FRAMEBUFFER, viewFramebufferis);</li> </ul> <p>with error code </p> <blockquote> <p>Thread 1: EXC_BAD_ACCSESS (code=1, adress=0x1508)</p> </blockquote> <p>Whole 'renderLineFromPoint:toPoint:' code bellow</p> <pre><code>- (void) renderLineFromPoint:(CGPoint)pradzia toPoint:(CGPoint)pabaiga { static GLfloat* vertexBuffer = NULL; static NSUInteger vertexMax = 64; NSUInteger vertexCount = 0, count, i; [context makeCurrentContext]; glBindFramebuffer(GL_FRAMEBUFFER, viewFramebufferis); //Convert from point to pixel CGFloat scale = self.contentsScale; pradzia.x *= scale; pradzia.y *= scale; pabaiga.x *= scale; pabaiga.y *= scale; //Vertex array buffer if(vertexBuffer == NULL) vertexBuffer = malloc(vertexMax * 2 * sizeof(GLfloat)); //Add points to buffer at X pixels count = MAX(ceilf(sqrtf((pabaiga.x - pradzia.x) * (pabaiga.x - pradzia.x) + (pabaiga.y - pradzia.y) * (pabaiga.y - pradzia.y)) / kBrushPixelStep), 1); for(i = 0; i &lt; count; ++i) { if (vertexCount == vertexMax) { vertexMax = 2 * vertexMax; vertexBuffer = realloc(vertexBuffer, vertexMax * 2 * sizeof(GLfloat)); } vertexBuffer[2 * vertexCount + 0] = pradzia.x + (pabaiga.x - pradzia.x) * ((GLfloat)i / (GLfloat)count); vertexBuffer[2 * vertexCount + 1] = pradzia.y + (pabaiga.y - pradzia.y) * ((GLfloat)i / (GLfloat)count); vertexCount += 1; } //Render vertex array glVertexPointer(2, GL_FLOAT, 0, vertexBuffer); glDrawArrays(GL_POINTS, 0, vertexCount); //Show buffer glBindRenderbuffer(GL_RENDERBUFFER, viewRenderbufferis); [context presentRenderbuffer:GL_RENDERBUFFER]; } </code></pre> <p>Anyone could help me? </p> <p>Or maybe someone could point me to similar sample code?</p> <p>That would be very useful even if someone links me to tutorial where is explained such a thing as drawing in real time or etc. I have no problems with mouse events tracking and registering its points. I just need somehow to make OpenGL to draw line between two points or to draw for example circle at each registered point. Any ideas?</p>
 

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