在OpenGL中更改顏色陣列以產生紅色色調

Question

我已經運行了一些屏幕保護程序的開放源代碼，並且想要了解如何修改Color Verticies的顏色陣列以產生色調而不是GREEN10噸

下面是筆者用來設置綠色代碼：

// Compute the new state of the color vertices 
- (void) computeColorVertices 
{ 
    int i,maxi,c; 
    GLfloat g, gstep, cursorglow; 

    c = 0; // To suppress spurious warning 
    gstep = stripParams.colorCycleSpeed; 
    // First, run down the strip cycling colors to bright then back to dark 
    g = startColor; 
    maxi = cursorDrawing ? cursorPos : stripSize; 
    for (i=0; i < maxi; i++) { 
     for (c = 0; c < 4; c++) { 
     // Some shade of green if cell is not empty 
     colorArray[16*i + 4*c + 1] = (cellState[i] == 0) ? 0.0 : g; 
     // Cells which are very bright are slightly whitened 
     colorArray[16*i + 4*c + 0] = ((g > 0.7) && (cellState[i] != 0)) ? (g - 0.6) : 0.0; 
     colorArray[16*i + 4*c + 2] = ((g > 0.7) && (cellState[i] != 0)) ? (g - 0.6) : 0.0; 
     // Transparent if cell is empty, otherwise opaque 
     colorArray[16*i + 4*c + 3] = (cellState[i] == 0) ? 0.0 : 1.0; 
     } 
     g += gstep; 
     if (g > 1.0) { 
     g = 0.2; 
     } 
    } 
    // Cycle the start color used above, to make the colors appear to fall 
    startColor -= stripParams.colorFallSpeed; 
    if (startColor < 0.2) { 
     startColor = 1.0; 
    } 

    // If the cursor's drawing, work up from its position making sure the cells aren't too dark 
    if (cursorDrawing) { 
     maxi = cursorPos - 1; 
     cursorglow = 0.8; 
     for (i = maxi; i >= 0 && cursorglow > 0.2; i--) { 
     // If there's some cursor-imparted glow left, use it 
     if (colorArray[16*i + 4*c + 1] < cursorglow) { 
      for (c = 0; c < 4; c++) { 
       // Some shade of green if cell is not empty 
       colorArray[16*i + 4*c + 1] = (cellState[i] == 0) ? 0.0 : cursorglow; 
       // Cells which are very bright are slightly whitened 
       colorArray[16*i + 4*c + 0] = ((cursorglow > 0.7) && (cellState[i] != 0)) ? (cursorglow - 0.6) : 0.0; 
       colorArray[16*i + 4*c + 2] = ((cursorglow > 0.7) && (cellState[i] != 0)) ? (cursorglow - 0.6) : 0.0; 
       // Transparent if cell is empty, otherwise opaque 
       colorArray[16*i + 4*c + 3] = (cellState[i] == 0) ? 0.0 : 1.0; 
      } 
     } 
     cursorglow -= gstep; 
     } 
    } 
} 

Answer 1

從似乎代碼：

colorArray[... + 1] = green 
colorArray[... + 0] = red 
colorArray[... + 2] = blue 
colorArray[... + 3] = alpha 

（因爲...部分始終是4的倍數）

所以，你應該能夠通過簡單地交換colorArray[... + 1]和colorArray[... + 0]處處將其更改爲紅色。將變量名g更改爲r將有助於未來的理智。