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POOpenGL Noob question: Starting Position for Drawing
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  1. POOpenGL Noob question: Starting Position for Drawing
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    copied!<p>I have a line that I am drawing but the starting point of the drawing is always dead center of the container view. How can I get the drawing to occur just inside of the right side of the view??</p> <pre><code>//Code - (void)drawView { // Replace the implementation of this method to do your own custom drawing GLfloat lineVertices[maxCurvePoint*2]; GLfloat lineVerticesGrid[GRID_LINES_HORZ*GRID_LINES_VERT*4]; GLfloat lineVerticesGridTexCoords[GRID_LINES_HORZ*GRID_LINES_VERT*4]; float currLevel = curve[(maxCurvePoint+curveStart-1)%maxCurvePoint]; int i; for (i=0; i&lt;maxCurvePoint; i++) { lineVertices[i*2] = i/(maxCurvePoint/2.0)-1.0; // X lineVertices[i*2+1] = curve[(i+curveStart)%maxCurvePoint]; // Y } for (i=0; i&lt;GRID_LINES_HORZ; i++) { float yval = 4.0*i/GRID_LINES_HORZ-2.0; lineVerticesGrid[i*4] = -2.0; // X lineVerticesGrid[i*4+1] = yval; // Y lineVerticesGrid[i*4+2] = 2.0; // X lineVerticesGrid[i*4+3] = yval; // Y lineVerticesGridTexCoords[i*4] = -2.3/1.4; // X lineVerticesGridTexCoords[i*4+1] = (yval-currLevel)/1.4; // Y lineVerticesGridTexCoords[i*4+2] = 1.7/1.4; // X lineVerticesGridTexCoords[i*4+3] = (yval-currLevel)/1.4+0.7; // Y } for (i=0; i&lt;GRID_LINES_VERT; i++) { int j = (GRID_LINES_HORZ+i)*4; float xval = 4.0*i/GRID_LINES_VERT-2.0; lineVerticesGrid[j] = 4.0*i/GRID_LINES_VERT-2.0; // X lineVerticesGrid[j+1] = -2.0; // Y lineVerticesGrid[j+2] = 4.0*i/GRID_LINES_VERT-2.0; // X lineVerticesGrid[j+3] = 2.0; // Y lineVerticesGridTexCoords[j] = (xval-0.7)/1.4; // X lineVerticesGridTexCoords[j+1] = currLevel/1.4+1.4+0.5; // Y lineVerticesGridTexCoords[j+2] = (xval-0.7)/1.4+0.7; // X lineVerticesGridTexCoords[j+3] = currLevel/1.4-1.4+0.5; // Y } [EAGLContext setCurrentContext:context]; glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer); glViewport(0, 0, backingWidth, backingHeight); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); glEnable(GL_DEPTH_TEST); //glEnable(GL_LINE_SMOOTH); glEnable(GL_POINT_SMOOTH); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrthof(-1.0f, 1.0f, -1.5f, 1.5f, -1.0f, 1.0f); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glScalef(0.8, 0.8, 1.0); glTranslatef(-0.2, 0, 0); glClearColor(0.0f, 0.0f, 0.0f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_TEXTURE_2D); glVertexPointer(2, GL_FLOAT, 0, spriteVertices); glEnableClientState(GL_VERTEX_ARRAY); glTexCoordPointer(2, GL_SHORT, 0, spriteTexcoords); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glPushMatrix(); glTranslatef(1.0, currLevel, -0.01); glColor4f(0.0, 0.0, 0.0, 1.0); //SpotLight - Should be kinda light /* if([colorTheme isEqualToString:@"blue"]) //SpotLight - Should be kinda light glColor4f(0.0, 0.0, 0.0, 1.0); else if ([colorTheme isEqualToString:@"red"]) glColor4f(0.5, 0.0, 0.0, 1.0); else if ([colorTheme isEqualToString:@"green"]) glColor4f(0.0, 0.5, 0.0, 1.0); else if ([colorTheme isEqualToString:@"orange"]) glColor4f(255.f/255.f, 101/255.f, 3/255.f, 1.0); else glColor4f(0.0, 0.0, 0.0, 1.0); */ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); glPopMatrix(); glVertexPointer(2, GL_FLOAT, 0, lineVerticesGrid); glEnableClientState(GL_VERTEX_ARRAY); glTexCoordPointer(2, GL_FLOAT, 0, lineVerticesGridTexCoords); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glLineWidth(1.0); glColor4f(0.0, 0.0, 0.0, 1.0);//Grid Lines behind spotlight...Very faint /* if([colorTheme isEqualToString:@"blue"]) //Grid Lines behind spotlight...Very faint glColor4f(0.0, 0.0, 0.0, 1.0); else if ([colorTheme isEqualToString:@"red"]) glColor4f(0.4, 0.0, 0.0, 1.0); else if ([colorTheme isEqualToString:@"green"]) glColor4f(0.0, 0.4, 0.0, 1.0); else if ([colorTheme isEqualToString:@"orange"]) glColor4f(255.f/255.f, 204/255.f, 7/255.f, 1.0); else glColor4f(0.0, 0.0, 0.0, 1.0); */ glDrawArrays(GL_LINES, 0, (GRID_LINES_HORZ+GRID_LINES_VERT)*2); glDisable(GL_TEXTURE_2D); glDisable(GL_DEPTH_TEST); glVertexPointer(2, GL_FLOAT, 0, lineVertices); glEnableClientState(GL_VERTEX_ARRAY); glLineWidth(9.0); glPointSize(9.0); if([colorTheme isEqualToString:@"blue"]) //Wave line before cursor outside color... little faint glColor4f(0.0, 0.5, 1.0, 0.2); else if ([colorTheme isEqualToString:@"red"]) glColor4f(0.5, 0.0, 0.0, 0.2); else if ([colorTheme isEqualToString:@"green"]) glColor4f(0.0, 0.5, 0.0, 0.2); else if ([colorTheme isEqualToString:@"orange"]) glColor4f(255.f/255.f, 194/255.f, 12/255.f, 0.2); else glColor4f(0.0, 0.0, 0.0, 1.0); glDrawArrays(GL_LINE_STRIP, 0, maxCurvePoint); glTranslatef(0, 0, .01); glDrawArrays(GL_POINTS, 0, maxCurvePoint); glPointSize(15.0); glDrawArrays(GL_POINTS, maxCurvePoint-1, 1); glTranslatef(0, 0, .01); glLineWidth(3.0); glPointSize(3.0); //Wave line before cursor inside if([colorTheme isEqualToString:@"blue"]) glColor4f(0.0, 0.5, 1.0, 0.7); else if ([colorTheme isEqualToString:@"red"]) glColor4f(0.5, 0.0, 1.0, 0.7); else if ([colorTheme isEqualToString:@"red"]) glColor4f(0.0, 0.5, 1.0, 0.7); else if ([colorTheme isEqualToString:@"orange"]) glColor4f(255.f/255.f, 220/255.f, 11/255.f, 0.7); else glColor4f(0.0, 0.0, 0.0, 1.0); glDrawArrays(GL_LINE_STRIP, 0, maxCurvePoint); glTranslatef(0, 0, .01); glDrawArrays(GL_POINTS, 0, maxCurvePoint); glPointSize(9.0); glDrawArrays(GL_POINTS, maxCurvePoint-1, 1); glTranslatef(0, 0, .01); glLineWidth(1.0); glPointSize(1.0); glColor4f(1.0, 1.0, 1.0, 1.0); glDrawArrays(GL_LINE_STRIP, 0, maxCurvePoint); glPointSize(5.0); glDrawArrays(GL_POINTS, maxCurvePoint-1, 1); glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer); [context presentRenderbuffer:GL_RENDERBUFFER_OES]; if (demoMode){ if (randomMode) curve[ curveStart ] = ((rand()%32768)/32768.0)*0.4-0.2; else curve[ curveStart ] = ekgMap[ curveStart ]; // ((rand()%32768)/32768.0)*0.4-0.2; // DLog(@"%f", ekgMap[ curveStart ]); } else{ if ([dataPoints count] ==0){ curve[ curveStart ] = 0.0; }else { if (!inverted) { curve[curveStart] = scaleByMid(self.min, self.max, [[dataPoints dequeue] floatValue]) /scaleFactor; // [[dataPoints dequeue] floatValue] /scaleFactor; // DLog(@"Queue Length: %d", [dataPoints count]); } else{ float point = scaleByMid(self.min, self.max, [[dataPoints dequeue] floatValue]) /scaleFactor; curve[curveStart] = (point -(point *2)); } } } curveStart = (curveStart+1)%maxCurvePoint; } </code></pre>
 

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