Window background visible through textures-CodePudding

What can I try to solve this problem? In this example (see a screenshot below) I am using OpenGL 1.1 with deprecated functions like: glEnableClientState, glMatrixMode, glTexCoordPointer, and so on. Thanks in advance.

You can see the whole example code in this thread:

Various window background values to show that I have alpha channels:

For glClearColor(1.f, 0.f, 0.f, 1.f);

For glClearColor(0.2f, 0.5f, 0.3f, 1.f);

My Settings:

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

GLuint createTexture(char *path)
{
    int h_image, w_image, cnt;

    unsigned char *data = stbi_load(path, &w_image, &h_image, &cnt, 0);

    if (data == NULL)
    {
        cout << "Failed to load an image" << endl;
        glfwTerminate();
        exit(-1);
    }

    GLuint texture;
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    {
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w_image, h_image, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
    }
    glBindTexture(GL_TEXTURE_2D, 0);

    stbi_image_free(data);

    return texture;
}

CodePudding user response：

Transparency is achieved with the alpha channel.

Wrong order on z-axis, for example: z = 15 for coin, z = 10 for enemy and z = 5 for player:

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

// Background
glBindTexture(GL_TEXTURE_2D, backgroundTexture);
glDisable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.f, 0.f, 0.f);
glScalef(256.f, 216.f, 1.f);
glDrawArrays(GL_TRIANGLE_STRIP, 16, 4);

glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_DEPTH_TEST);
glBindTexture(GL_TEXTURE_2D, spriteTexture);

// Coin
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(178.f, 120.f, 15.f);
glScalef(16.f, 16.f, 1.f);
glDrawArrays(GL_TRIANGLE_STRIP, 24, 4);

// Enemy
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(194.f, 184.f, 10.f);
glScalef(16.f, 16.f, 1.f);
glDrawArrays(GL_TRIANGLE_STRIP, 20, 4);

// Player
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(playerBody->GetPosition().x * WORLD_SCALE,
                playerBody->GetPosition().y * WORLD_SCALE, 5.f);
glScalef(16.f, 16.f, 1.f);
glDrawArrays(GL_TRIANGLE_STRIP, drawingIndex, 4);

glfwSwapBuffers(window);