CODEWITHSUNDEEP
opengl
Anton Stafeyev
Anton Stafeyev

Reputation: 831

OpenGL Drawing multiple objects

Do i need to have separate draw call for each object i would like to render and then swap buffers?

As i understand i have one VBO rendered, then another VBO is bidden and is drawn, and after all that i am swapping buffers to present the back buffer.

for Example //Then Render

    float vertices[] = {
    -0.5f, -0.5f, 0.0f,
    0.5f, -0.5f, 0.0f,
    0.0f,  0.5f, 0.0f
    };

    //Create Vertex Buffer
    GLint VBO = 0;
    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glUseProgram(ShaderProgram);
    glDrawArrays(GL_TRIANGLES, 0, 3);

Here i draw a single triangle, how would one go about drawing a second triangle with different shader program

Upvotes: 0

Views: 1778

Answers (1)

Ifeanyi Nmoye
Ifeanyi Nmoye

Reputation: 72

To draw different objects, you need different VBOs and that means a different draw call for every different object. If you want to draw a particular object more than once, you can use instancing or bind and draw the same VBO more than once. You can create one gigantic VBO for all objects but since you are a beginner, stick to one VBO per object for now.

Upvotes: 1

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