OpenGLオブジェクトの色と動きが正しく交わらない

Question

私のプログラムは光源が中心（球）にある部屋です。

私は左の球の動きを作り、右のx軸に沿っただろう「ディスコ」モードを作りたいです。同時に赤と青の色を交互に変えます。

これは、このモードを有効にするコードのセクションです。 g_disco_modeは、モードが選択されると真となる変数です。

static void update_scene() 
{ 
    ... 

    // Disco mode 
    if (g_disco_mode) 
    { 
     bool movement_increase = true; 
     bool color_increase = true; 
     float floor = -0.1f; 
     float ceiling = 1.0f; 
     float increment = 0.01f; 

     // Movement of spotlight 
     if (movement_increase == true && g_lightProperties.direction[0] <= ceiling) 
     { 
      g_lightProperties.direction[0] += increment; 

      if (g_lightProperties.direction[0] >= ceiling) { movement_increase = false; } 
     } 

     if (movement_increase == false && g_lightProperties.direction[0] >= floor) 
     { 
      g_lightProperties.direction[0] -= increment; 

      if (g_lightProperties.direction[0] <= floor) { movement_increase = true; } 
     } 

     // Changing of color 
     g_spotlight_ambient[0] += 0.01f; 

     if (color_increase == true && g_spotlight_ambient[0] <= ceiling) 
     { 
      g_spotlight_ambient[0] += increment; 

      if (g_spotlight_ambient[0] >= ceiling) { color_increase = false; } 
     } 

     if (color_increase == false && g_spotlight_ambient[0] >= floor) 
     { 
      g_spotlight_ambient[0] -= increment; 

      if (g_spotlight_ambient[0] <= floor) { color_increase = true; } 
     } 
    } 
} 

私は球が、それはceilingに達するまで右に移動し、それがfloorに当たるまで左に移動するようなコードのこのセクションを書きました。これは、g_lightProperties.directionを増減することによって行われます。 色の変更も同様に動作します。しかし、私がプログラムを実行すると球はceilingに当たるまで動き、停止します。左へ移動しません。色は赤色に変わらず、青色に戻りません。どうしてこんなことに？

あなたが 天井または 床に達し、その後、あなたはあなたのコードは次のように何とかなるはず方向に

を変更する必要がありますされているかどうかをテストする必要が

私のプログラム

// Values for spotlight 
glm::vec3 g_spotlight_ambient(0.2f, 0.2f, 0.2f); 
glm::vec3 g_spotlight_diffuse(0.0f, 0.5f, 1.0f); 
glm::vec3 g_spotlight_specular(0.0f, 0.5f, 1.0f); 

bool g_switchOn = true;  // toggle the light on/off 
bool g_disco_mode = false; // makes the lights move around and change color 

static void init(GLFWwindow* window) 
{ 
    ... 

// initialise light and material properties 
    g_lightProperties.position = glm::vec4(0.0f, 2.0f, 0.0f, 1.0f); 
    g_lightProperties.ambient = glm::vec4(g_spotlight_ambient[0], g_spotlight_ambient[1], g_spotlight_ambient[2], 1.0f); 
    g_lightProperties.diffuse = glm::vec4(g_spotlight_diffuse[0], g_spotlight_diffuse[1], g_spotlight_diffuse[2], 1.0f); 
    g_lightProperties.specular = glm::vec4(g_spotlight_specular[0], g_spotlight_specular[1], g_spotlight_specular[2], 1.0f); 
    g_lightProperties.shininess = 10.0f; 
    g_lightProperties.attenuation = glm::vec3(1.0f, 0.0f, 0.0f); 
    g_lightProperties.cutoffAngle = 100.0f; 
    g_lightProperties.direction = glm::vec3(0.0f, -1.0f, 0.0f); 

    ... 
} 

// function used to update the scene 
static void update_scene() 
{ 
    static float rotateAngle = 0.0f; 
    static float cutOffAngle = g_lightProperties.cutoffAngle; 

    rotateAngle -= 1.0f; 

    // update model matrix 
    g_modelMatrix_mesh[0] = glm::rotate(glm::radians(rotateAngle), glm::vec3(0.0f, 1.0f, 0.0f)) 
      * glm::translate(glm::vec3(-0.4f, 0.1f, 0.0f)) * glm::scale(glm::vec3(0.3f, 0.3f, 0.3f)); 
    g_modelMatrix_mesh[1] = glm::rotate(glm::radians(rotateAngle), glm::vec3(0.0f, 1.0f, 0.0f)) 
      * glm::translate(glm::vec3(0.4f, 0.3f, 0.0f)) * glm::scale(glm::vec3(0.2f, 0.2f, 0.2f)); 
    g_modelMatrix_mesh[2] = glm::translate(g_lightProperties.direction) 
      * glm::translate(glm::vec3(0.0f, 2.0f, 0.0f)) * glm::scale(glm::vec3(0.2f, 0.2f, 0.2f)); 

    // update spotlight 
    g_lightProperties.ambient = glm::vec4(g_spotlight_ambient[0], g_spotlight_ambient[1], g_spotlight_ambient[2], 1.0f); 
    g_lightProperties.diffuse = glm::vec4(g_spotlight_diffuse[0], g_spotlight_diffuse[1], g_spotlight_diffuse[2], 1.0f); 
    g_lightProperties.specular = glm::vec4(g_spotlight_specular[0], g_spotlight_specular[1], g_spotlight_specular[2], 1.0f); 

    // Disco mode 
    if (g_disco_mode) 
    { 
     bool movement_increase = true; 
     bool color_increase = true; 
     float floor = -0.1f; 
     float ceiling = 1.0f; 
     float increment = 0.01f; 

     // Movement of spotlight 
     if (movement_increase == true && g_lightProperties.direction[0] <= ceiling) 
     { 
      g_lightProperties.direction[0] += increment; 

      if (g_lightProperties.direction[0] >= ceiling) { movement_increase = false; } 
     } 

     if (movement_increase == false && g_lightProperties.direction[0] >= floor) 
     { 
      g_lightProperties.direction[0] -= increment; 

      if (g_lightProperties.direction[0] <= floor) { movement_increase = true; } 
     } 

     // Changing of color 
     g_spotlight_ambient[0] += 0.01f; 

     if (color_increase == true && g_spotlight_ambient[0] <= ceiling) 
     { 
      g_spotlight_ambient[0] += increment; 

      if (g_spotlight_ambient[0] >= ceiling) { color_increase = false; } 
     } 

     if (color_increase == false && g_spotlight_ambient[0] >= floor) 
     { 
      g_spotlight_ambient[0] -= increment; 

      if (g_spotlight_ambient[0] <= floor) { color_increase = true; } 
     } 
    } 

} 

// function used to render the scene 
static void render_scene() 
{ 
    glBindVertexArray(g_VAO[0]);  // make VAO active 

// Material Properties - Planes 
    glUniform4fv(g_materialAmbientIndex, 1, &g_materialProperties.ambient[0]); 
    glUniform4fv(g_materialDiffuseIndex, 1, &g_materialProperties.diffuse[0]); 
    glUniform4fv(g_materialSpecularIndex, 1, &g_materialProperties.specular[0]); 

    glUniform4fv(g_lightPositionIndex, 1, &g_lightProperties.position[0]); 
    glUniform4fv(g_lightAmbientIndex, 1, &g_lightProperties.ambient[0]); 
    glUniform4fv(g_lightDiffuseIndex, 1, &g_lightProperties.diffuse[0]); 
    glUniform4fv(g_lightSpecularIndex, 1, &g_lightProperties.specular[0]); 
    glUniform1fv(g_lightShininessIndex, 1, &g_lightProperties.shininess); 
    glUniform3fv(g_lightAttenuationIndex, 1, &g_lightProperties.attenuation[0]); 
    glUniform1fv(g_lightCutoffAngleIndex, 1, &g_lightProperties.cutoffAngle); 
    glUniform3fv(g_lightDirectionIndex, 1, &g_lightProperties.direction[0]); 

    ... 
} 

int main(void) 
{ 
    TwBar *TweakBar;   // pointer to a tweak bar 

    ... 

    // initialise AntTweakBar 
    TwInit(TW_OPENGL_CORE, NULL); 

    // give tweak bar the size of graphics window 
    TwWindowSize(g_windowWidth, g_windowHeight); 
    TwDefine(" TW_HELP visible=false "); // disable help menu 
    TwDefine(" GLOBAL fontsize=3 ");  // set large font size 

    // create a tweak bar 
    TweakBar = TwNewBar("Main"); 
    TwDefine(" Main label='Controls' refresh=0.02 text=light size='220 600' "); 

    // create display entries 
    TwAddVarRW(TweakBar, "Wireframe", TW_TYPE_BOOLCPP, &g_wireFrame, " group='Display' "); 

    // display a separator 
    TwAddSeparator(TweakBar, NULL, NULL); 

    // create spotlight entries 
    TwAddVarRW(TweakBar, "Cutoff", TW_TYPE_FLOAT, &g_lightProperties.cutoffAngle, " group='Spotlight' min=-180.0 max=180.0 step=1.0 "); 
    TwAddVarRW(TweakBar, "Direction: x", TW_TYPE_FLOAT, &g_lightProperties.direction[0], " group='Spotlight' min=-1.0 max=1.0 step=0.1"); 
    TwAddVarRW(TweakBar, "Direction: y", TW_TYPE_FLOAT, &g_lightProperties.direction[1], " group='Spotlight' min=-1.0 max=1.0 step=0.1"); 
    TwAddVarRW(TweakBar, "Direction: z", TW_TYPE_FLOAT, &g_lightProperties.direction[2], " group='Spotlight' min=-1.0 max=1.0 step=0.1"); 
    // create transformation entries 
    TwAddVarRW(TweakBar, "A Red", TW_TYPE_FLOAT, &g_spotlight_ambient[0], " group='Ambient' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "A Green", TW_TYPE_FLOAT, &g_spotlight_ambient[1], " group='Ambient' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "A Blue", TW_TYPE_FLOAT, &g_spotlight_ambient[2], " group='Ambient' min=-1.0 max=1.0 step=0.01"); 

    TwAddVarRW(TweakBar, "D Red", TW_TYPE_FLOAT, &g_spotlight_diffuse[0], " group='Diffuse' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "D Green", TW_TYPE_FLOAT, &g_spotlight_diffuse[1], " group='Diffuse' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "D Blue", TW_TYPE_FLOAT, &g_spotlight_diffuse[2], " group='Diffuse' min=-1.0 max=1.0 step=0.01"); 

    TwAddVarRW(TweakBar, "S Red", TW_TYPE_FLOAT, &g_spotlight_specular[0], " group='Specular' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "S Green", TW_TYPE_FLOAT, &g_spotlight_specular[1], " group='Specular' min=-1.0 max=1.0 step=0.01"); 
    TwAddVarRW(TweakBar, "S Blue", TW_TYPE_FLOAT, &g_spotlight_specular[2], " group='Specular' min=-1.0 max=1.0 step=0.01"); 

    TwAddVarRW(TweakBar, "Light", TW_TYPE_BOOLCPP, &g_switchOn, " group='Toggle ON/OFF' "); 
    TwAddVarRW(TweakBar, "Disco", TW_TYPE_BOOLCPP, &g_disco_mode, " group='Toggle ON/OFF' "); 

    // initialise rendering states 
    init(window); 

    // the rendering loop 
    while (!glfwWindowShouldClose(window)) 
    { 
     g_camera.update(window); // update camera 

     if (g_wireFrame) 
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); 

     update_scene();  // update the scene 
     render_scene();  // render the scene 

     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); 

     TwDraw();   // draw tweak bar(s) 

     glfwSwapBuffers(window); // swap buffers 
     glfwPollEvents();   // poll for events 
    } 

    ... 
} 

Answer 1

：

if (movement_increase) 
{ 
    // if less than ceiling keep increasing 
    movement_increase = g_lightProperties.direction[0] < ceiling; 
} 
else 
{ 
    // if less or equal floor change to increasing 
    movement_increase = g_lightProperties.direction[0] <= floor; 
} 
g_lightProperties.direction[0] += movement_increase ? increment : -increment; 

if (color_increase) 
    color_increase = g_spotlight_ambient[0] < 1.0; 
else 
    color_increase = g_spotlight_ambient[0] <= 0.0; 
g_spotlight_ambient[0] += color_increase ? increment : -increment; 

さらに、変数movement_increaseとcolor_increaseはローカル変数なので、連続して初期化されます。どちらかあなたはグローバルvaribalesを使用するか、あなたは彼らにstaticをdelcare：

static bool movement_increase = true; 
static bool color_increase = true;