OOSunEntity(Private) Category Reference

Instance Methods
(void)	- calculateGLArrays:width:zDistance:
(void)	- drawOpaqueParts
(void)	- drawTranslucentParts

Detailed Description

Definition at line 41 of file OOSunEntity.m.

Method Documentation

calculateGLArrays:width:zDistance:

- (void) calculateGLArrays:		(GLfloat)	inner_radius
width:		(GLfloat)	width
zDistance:		(GLfloat)	z_distance

Extends class OOSunEntity.

Definition at line 1 of file OOSunEntity.m.

                          :(GLfloat)inner_radius width:(GLfloat)width zDistance:(GLfloat)z_distance
{
//  if (EXPECT_NOT(inner_radius >= z_distance))  return;    // inside the sphere
    
    GLfloat activity[8] = {0.84, 0.74, 0.64, 0.54, 
                                                 0.3 , 0.4 , 0.7 , 0.8};
    
    GLfloat             si, ci;
    GLfloat             rv0, rv1, rv2, c0, c1, c2;
    GLfloat             pt0, pt1; 
    
    unsigned short      i, j, k;
    GLfloat             theta = 0.0f, delta;
    delta = M_PI / 180.0f;  // Convert step from degrees to radians
    pt0=(1.0 - corona_stage) * corona_blending;
    pt1=corona_stage * corona_blending;
 
    sunVertices[0] = 0.0;
    sunVertices[1] = 0.0;
    sunVertices[2] = 0.0;
    k = 3;
    for (j = 0 ; j <= 4 ; j++)
    {
        GLfloat r = inner_radius;
        switch (j) {
        case 4:
            r += width;
            break;
        case 3:
            r += width/1.5f;
            break;
        case 2:
            r += width/3.0f;
            break;
        case 1:
                r += width/15.0f;
            break;
        }
        theta = 0.0;
        for (i = 0 ; i < 360 ; i++)
        {
            GLfloat rm = 1.0;
            if (j >= 1 && j < 4)
            {
                rm = 1.0 + ((0.04/j)*(pt0 * (rvalue[i]+rvalue[i+1]+rvalue[i+2]) + pt1 * (rvalue[i+360]+rvalue[i+361]+rvalue[i+362])))/3;
            }
            GLfloat z = r * r * rm * rm / z_distance;
            si = sinf(theta);
            ci = cosf(theta);
            theta += delta;
            sunVertices[k++] = si * r * rm;
            sunVertices[k++] = ci * r * rm;
            sunVertices[k++] = -z;
        }
    }
 
    GLfloat blackColor[4] = {0.0,0.0,0.0,0.0};
    GLfloat *color = blackColor;
    GLfloat alpha = 0.0;
 
    k=0;
    sunColors[k++] = discColor[0];
    sunColors[k++] = discColor[1];
    sunColors[k++] = discColor[2];
    sunColors[k++] = discColor[3] * _sunCoronaAlphaFactor;
    
    for (j = 0 ; j <= 4 ; j++)
    {
        switch (j) {
        case 4:
            color = blackColor;
            alpha = 0.0;
            break;
        case 3:
            color = outerCoronaColor;
            alpha = 0.1;
            break;
        case 2:
            color = outerCoronaColor;
            alpha = 0.6;
            break;
        case 1:
            color = discColor;
            alpha = 0.95;
            break;
        case 0:
            color = discColor;
            alpha = 1.0;
            break;
        }
        for (i = 0 ; i < 360 ; i++)
        {
            if (j == 0) 
            {
                sunColors[k++] = color[0];
                sunColors[k++] = color[1];
                sunColors[k++] = color[2];
                sunColors[k++] = alpha * _sunCoronaAlphaFactor;
            }
            else
            {
                rv0 = pt0 * rvalue[i] + pt1 * rvalue[i + 360];
                rv1 = pt0 * rvalue[i + 1] + pt1 * rvalue[i + 361];
                rv2 = pt0 * rvalue[i + 2] + pt1 * rvalue[i + 362];
                c0 = color[0] * (activity[j-1] + rv0*activity[j+3]);
                c1 = color[1] * (activity[j-1] + rv1*activity[j+3]);
                c2 = color[2] * (activity[j-1] + rv2*activity[j+3]);
                if (c1 > c2 && c1 > c0)
                {
                    c1 = fmaxf(c0,c2);
                }
 
                sunColors[k++] = c0;
                sunColors[k++] = c1;
                sunColors[k++] = c2;
                sunColors[k++] = alpha * _sunCoronaAlphaFactor;
            }   
        }
    }
}

drawOpaqueParts

- (void) drawOpaqueParts

Extends class OOSunEntity.

Definition at line 1 of file OOSunEntity.m.

{
    float sqrt_zero_distance = sqrt(cam_zero_distance);
    float effective_radius = collision_radius;
    float effective_cor16k = cor16k;
 
    /* At very long ranges the floating point inaccuracies make a
     * complete mess of the calculations, so if the sun is more than
     * 1E9 away, draw it closer but smaller. Painter's algorithm
     * should stop oddities with planets transiting it */
    float large_distance_compensator = sqrt_zero_distance / 1000000000.0f; //1E9
    if (large_distance_compensator > 1.0f)
    {
        sqrt_zero_distance /= large_distance_compensator;
        effective_radius /= large_distance_compensator;
        effective_cor16k /= large_distance_compensator;
    }
 
    OO_ENTER_OPENGL();
    
    OOSetOpenGLState(OPENGL_STATE_ADDITIVE_BLENDING);
 
    if ([UNIVERSE reducedDetail])
    {   
        int subdivideLevel = 2;     // 4 is probably the maximum!
        float drawFactor = [[UNIVERSE gameView] viewSize].width / 100.0;
        float drawRatio2 = drawFactor * effective_radius / sqrt_zero_distance; // equivalent to size on screen in pixels
    
        if (cam_zero_distance > 0.0f)
        {
            subdivideLevel = 2 + floorf(drawRatio2);
            if (subdivideLevel > 4)
                subdivideLevel = 4;
        }
    
    /*
     
    The depth test gets disabled in parts of this and instead
    we rely on the painters algorithm instead.
     
    The depth buffer isn't granular enough to cope with huge objects at vast
    distances.
     
    */
        BOOL ignoreDepthBuffer = cam_zero_distance > effective_radius * effective_radius * 25;
    
        int steps = 2 * (MAX_SUBDIVIDE - subdivideLevel);
 
        // Close enough not to draw flat?
        if (ignoreDepthBuffer)  OOGL(glDisable(GL_DEPTH_TEST));
        
        OOGL(glColor3fv(discColor));
        // FIXME: use vertex arrays
        OOGL(glDisable(GL_BLEND));
        OOGLBEGIN(GL_TRIANGLE_FAN);
        GLDrawBallBillboard(effective_radius, steps, sqrt_zero_distance);
        OOGLEND();
        OOGL(glEnable(GL_BLEND));
 
        if (ignoreDepthBuffer)  OOGL(glEnable(GL_DEPTH_TEST)); 
    
    }
    else
    {
        [self calculateGLArrays:effective_radius
                          width:effective_cor16k
                      zDistance:sqrt_zero_distance];
        OOGL(glDisable(GL_BLEND));
        OOGL(glVertexPointer(3, GL_FLOAT, 0, sunVertices));
        
        OOGL(glEnableClientState(GL_COLOR_ARRAY));
        OOGL(glColorPointer(4, GL_FLOAT, 0, sunColors));
        
        OOGL(glDrawElements(GL_TRIANGLES, 3*360, GL_UNSIGNED_INT, sunTriangles));
 
        OOGL(glDisableClientState(GL_COLOR_ARRAY));
        OOGL(glEnable(GL_BLEND));
 
        
    }
    
    OOVerifyOpenGLState();
    OOCheckOpenGLErrors(@"SunEntity after drawing %@", self);
}

drawTranslucentParts

- (void) drawTranslucentParts

Extends class OOSunEntity.

Definition at line 1 of file OOSunEntity.m.

{
    if ([UNIVERSE reducedDetail]) 
    {
        return;
    }
    
    OO_ENTER_OPENGL();
    
    OOSetOpenGLState(OPENGL_STATE_ADDITIVE_BLENDING);
 
    OOGL(glVertexPointer(3, GL_FLOAT, 0, sunVertices));
 
    OOGL(glEnableClientState(GL_COLOR_ARRAY));
    OOGL(glColorPointer(4, GL_FLOAT, 0, sunColors));
    OOGL(glDrawElements(GL_TRIANGLES, 24*360, GL_UNSIGNED_INT, sunTriangles+(3*360)));
 
    OOGL(glDisableClientState(GL_COLOR_ARRAY));
 
 
}

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The documentation for this category was generated from the following file:

• src/Core/Entities/OOSunEntity.m