ios FlowCover效果demo

demo功能：flowcover 效果，正反无限循环滚动，每个cover都有单独的倒影

demo说明：项目中FlowCover Classes文件夹是存放核心类。

demo接图：

demo主要代码：绘制部分

[csharp]
- (void)drawTile:(int)index atOffset:(double)off
{
    FlowCoverRecord *fcr = [self getTileAtIndex:index];
    GLfloat m[16];
    memset(m,0,sizeof(m));
    m[10] = 1;
    m[15] = 1;
    m[0] = 1;
    m[5] = 1;
    double trans = off * SPREADIMAGE;

    double f = off * FLANKSPREAD;
    if (f < -FLANKSPREAD) {
        f = -FLANKSPREAD;
    } else if (f > FLANKSPREAD) {
        f = FLANKSPREAD;
    }
    m[3] = -f;
    m[0] = 1-fabs(f);
    double sc = 0.45 * (1 - fabs(f));
    trans += f * 1;

    glPushMatrix();
    glBindTexture(GL_TEXTURE_2D,fcr.texture);
    glTranslatef(trans, 0, 0);
    glScalef(sc,sc,1.0);
    glMultMatrixf(m);
    glDrawArrays(GL_TRIANGLE_STRIP,0,4);

    // reflect
    glTranslatef(0,-2,0);
    glScalef(1,-1,1);
    glColor4f(0.5,0.5,0.5,0.5);
    glDrawArrays(GL_TRIANGLE_STRIP,0,4);
    glColor4f(1,1,1,1);

    glPopMatrix();
}

- (void)draw
{
    /*
     * Get the current aspect ratio and initialize the viewport
     */

    double aspect = ((double)backingWidth)/backingHeight;

    glViewport(0,0,backingWidth,backingHeight);
    glDisable(GL_DEPTH_TEST);               // using painters algorithm

    glClearColor(0,0,0,0);
    glVertexPointer(3,GL_FLOAT,0,GVertices);
    glEnableClientState(GL_VERTEX_ARRAY);
    glTexCoordPointer(2, GL_SHORT, 0, GTextures);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);

    glEnable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
    glEnable(GL_BLEND);

    /*
     * Setup for clear
     */

    [EAGLContext setCurrentContext:context];

    glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
    glClear(GL_COLOR_BUFFER_BIT);

    /*
     * Set up the basic coordinate system
     */

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glScalef(1,aspect,1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    //modify by chenwh 2010-01-06 for round view begin
    /*
     * Change from Alesandro Tagliati <alessandro.tagliati@gmail.com>:
     * We don't need to draw all the tiles, just the visible ones. We guess
     * there are 6 tiles visible; that can be adjusted by altering the
     * constant
     */
    /*
    int i,len = [self numTiles];
    int mid = (int)floor(offset + 0.5);
    int iStartPos = mid - VISTILES;
    if (iStartPos<0) {
        iStartPos=0;
    }
    for (i = iStartPos; i < mid; ++i) {
        [self drawTile:i atOffset:i-offset];
    }

    int iEndPos=mid + VISTILES;
    if (iEndPos >= len) {
        iEndPos = len-1;
    }
    for (i = iEndPos; i >= mid; --i) {
        [self drawTile:i atOffset:i-offset];
    }
    */

    int len = [self numTiles];
    int iStartPos = -VISTILES;
    int iEndPos = VISTILES;
    int mid = 0;

    int pageCount = (int)offset;
    double moveOffset;
    if (offset < 0) {
        moveOffset = offset - ceil(offset);
    } else {
        moveOffset = offset - floor(offset);
    }

    int index, position;
    //NSLog(@"offset=%.2f, pageCount=%d, moveOffset=%.2f", offset, pageCount, moveOffset);
    for (position = iStartPos; position < mid; ++position) {
        index = (len + position + pageCount) % len;
        if (index < 0) {
            index = len + index;
        }
        //NSLog(@"index=%d, position=%d", index, position);
        [self drawTile:index atOffset:position - moveOffset];
    }
    for (position = iEndPos; position >= mid; --position) {
        index = (position + pageCount) % len;
        if (index < 0) {
            index = len + index;
        }
        //NSLog(@"index=%d, posit

补充：移动开发 , IOS ,