Java Code Examples for javax.media.opengl.GL2#glBegin()

@Override
public void drawCircle(Vec2 center, float radius, Color3f color) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);
  float theta = 2 * MathUtils.PI / NUM_CIRCLE_POINTS;
  float c = MathUtils.cos(theta);
  float s = MathUtils.sin(theta);
  float x = radius;
  float y = 0;
  float cx = center.x;
  float cy = center.y;
  gl.glBegin(GL2.GL_LINE_LOOP);
  gl.glColor4f(color.x, color.y, color.z, 1);
  for (int i = 0; i < NUM_CIRCLE_POINTS; i++) {
    gl.glVertex3f(x + cx, y + cy, 0);
    // apply the rotation matrix
    float temp = x;
    x = c * x - s * y;
    y = s * temp + c * y;
  }
  gl.glEnd();
  gl.glPopMatrix();
}
 

@Override
public void drawTransform(Transform xf) {
  GL2 gl = panel.getGL().getGL2();
  getWorldToScreenToOut(xf.p, temp);
  temp2.setZero();
  float k_axisScale = 0.4f;

  gl.glBegin(GL2.GL_LINES);
  gl.glColor3f(1, 0, 0);

  temp2.x = xf.p.x + k_axisScale * xf.q.c;
  temp2.y = xf.p.y + k_axisScale * xf.q.s;
  getWorldToScreenToOut(temp2, temp2);
  gl.glVertex2f(temp.x, temp.y);
  gl.glVertex2f(temp2.x, temp2.y);

  gl.glColor3f(0, 1, 0);
  temp2.x = xf.p.x + -k_axisScale * xf.q.s;
  temp2.y = xf.p.y + k_axisScale * xf.q.c;
  getWorldToScreenToOut(temp2, temp2);
  gl.glVertex2f(temp.x, temp.y);
  gl.glVertex2f(temp2.x, temp2.y);
  gl.glEnd();
}
 

@SuppressWarnings("static-access")
protected void render(GL2 gl2) {
    if (use_draw_pixels_ || view_width_ == 0 || view_height_ == 0) {
        return;
    }

    assert (initialized_context_ != null);

    final float[] vertex_data = {
            //tu,   tv,     x,     y,    z
            0.0f, 1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f };
    FloatBuffer vertices = FloatBuffer.wrap(vertex_data);

    gl2.glClear(gl2.GL_COLOR_BUFFER_BIT | gl2.GL_DEPTH_BUFFER_BIT);

    gl2.glMatrixMode(gl2.GL_MODELVIEW);
    gl2.glLoadIdentity();

    // Match GL units to screen coordinates.
    gl2.glViewport(0, 0, view_width_, view_height_);
    gl2.glMatrixMode(gl2.GL_PROJECTION);
    gl2.glLoadIdentity();

    // Draw the background gradient.
    gl2.glPushAttrib(gl2.GL_ALL_ATTRIB_BITS);
    gl2.glBegin(gl2.GL_QUADS);
    gl2.glColor4f(1.0f, 0.0f, 0.0f, 1.0f);  // red
    gl2.glVertex2f(-1.0f, -1.0f);
    gl2.glVertex2f(1.0f, -1.0f);
    gl2.glColor4f(0.0f, 0.0f, 1.0f, 1.0f);  // blue
    gl2.glVertex2f(1.0f, 1.0f);
    gl2.glVertex2f(-1.0f, 1.0f);
    gl2.glEnd();
    gl2.glPopAttrib();

    // Rotate the view based on the mouse spin.
    if (spin_x_ != 0) {
        gl2.glRotatef(-spin_x_, 1.0f, 0.0f, 0.0f);
    }
    if (spin_y_ != 0) {
        gl2.glRotatef(-spin_y_, 0.0f, 1.0f, 0.0f);
    }

    if (transparent_) {
        // Alpha blending style. Texture values have premultiplied alpha.
        gl2.glBlendFunc(gl2.GL_ONE, gl2.GL_ONE_MINUS_SRC_ALPHA);

        // Enable alpha blending.
        gl2.glEnable(gl2.GL_BLEND);
    }

    // Enable 2D textures.
    gl2.glEnable(gl2.GL_TEXTURE_2D);

    // Draw the facets with the texture.
    assert (texture_id_[0] != 0);
    gl2.glBindTexture(gl2.GL_TEXTURE_2D, texture_id_[0]);
    gl2.glInterleavedArrays(gl2.GL_T2F_V3F, 0, vertices);
    gl2.glDrawArrays(gl2.GL_QUADS, 0, 4);

    // Disable 2D textures.
    gl2.glDisable(gl2.GL_TEXTURE_2D);

    if (transparent_) {
        // Disable alpha blending.
        gl2.glDisable(gl2.GL_BLEND);
    }
}
 

@Override
public void drawPoint(Vec2 argPoint, float argRadiusOnScreen, Color3f argColor) {
  Vec2 vec = getWorldToScreen(argPoint);
  GL2 gl = panel.getGL().getGL2();
  gl.glPointSize(argRadiusOnScreen);
  gl.glBegin(GL2.GL_POINTS);
  gl.glVertex2f(vec.x, vec.y);
  gl.glEnd();
}
 

@Override
public void drawPolygon(Vec2[] vertices, int vertexCount, Color3f color) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);
  gl.glBegin(GL2.GL_LINE_LOOP);
  gl.glColor4f(color.x, color.y, color.z, 1f);
  for (int i = 0; i < vertexCount; i++) {
    Vec2 v = vertices[i];
    gl.glVertex2f(v.x, v.y);
  }
  gl.glEnd();
  gl.glPopMatrix();
}
 

@Override
public void drawCircle(Vec2 center, float radius, Vec2 axis, Color3f color) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);
  float theta = 2 * MathUtils.PI / NUM_CIRCLE_POINTS;
  float c = MathUtils.cos(theta);
  float s = MathUtils.sin(theta);
  float x = radius;
  float y = 0;
  float cx = center.x;
  float cy = center.y;
  gl.glBegin(GL2.GL_LINE_LOOP);
  gl.glColor4f(color.x, color.y, color.z, 1);
  for (int i = 0; i < NUM_CIRCLE_POINTS; i++) {
    gl.glVertex3f(x + cx, y + cy, 0);
    // apply the rotation matrix
    float temp = x;
    x = c * x - s * y;
    y = s * temp + c * y;
  }
  gl.glEnd();
  gl.glBegin(GL2.GL_LINES);
  gl.glVertex3f(cx, cy, 0);
  gl.glVertex3f(cx + axis.x * radius, cy + axis.y * radius, 0);
  gl.glEnd();
  gl.glPopMatrix();
}
 

@Override
public void drawSegment(Vec2 p1, Vec2 p2, Color3f color) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);
  gl.glBegin(GL2.GL_LINES);
  gl.glColor3f(color.x, color.y, color.z);
  gl.glVertex3f(p1.x, p1.y, 0);
  gl.glVertex3f(p2.x, p2.y, 0);
  gl.glEnd();
  gl.glPopMatrix();
}
 

@Override
public void drawParticles(Vec2[] centers, float radius, ParticleColor[] colors, int count) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);

  float theta = 2 * MathUtils.PI / NUM_CIRCLE_POINTS;
  float c = MathUtils.cos(theta);
  float s = MathUtils.sin(theta);

  float x = radius;
  float y = 0;

  for (int i = 0; i < count; i++) {
    Vec2 center = centers[i];
    float cx = center.x;
    float cy = center.y;
    gl.glBegin(GL2.GL_TRIANGLE_FAN);
    if (colors == null) {
      gl.glColor4f(1, 1, 1, .4f);
    } else {
      ParticleColor color = colors[i];
      gl.glColor4b(color.r, color.g, color.b, color.a);
    }
    for (int j = 0; j < NUM_CIRCLE_POINTS; j++) {
      gl.glVertex3f(x + cx, y + cy, 0);
      float temp = x;
      x = c * x - s * y;
      y = s * temp + c * y;
    }
    gl.glEnd();
  }
  gl.glPopMatrix();
}
 

@Override
public void drawParticlesWireframe(Vec2[] centers, float radius, ParticleColor[] colors, int count) {
  GL2 gl = panel.getGL().getGL2();
  gl.glPushMatrix();
  transformViewport(gl, zero);

  float theta = 2 * MathUtils.PI / NUM_CIRCLE_POINTS;
  float c = MathUtils.cos(theta);
  float s = MathUtils.sin(theta);

  float x = radius;
  float y = 0;

  for (int i = 0; i < count; i++) {
    Vec2 center = centers[i];
    float cx = center.x;
    float cy = center.y;
    gl.glBegin(GL2.GL_LINE_LOOP);
    if (colors == null) {
      gl.glColor4f(1, 1, 1, 1);
    } else {
      ParticleColor color = colors[i];
      gl.glColor4b(color.r, color.g, color.b, (byte) 127);
    }
    for (int j = 0; j < NUM_CIRCLE_POINTS; j++) {
      gl.glVertex3f(x + cx, y + cy, 0);
      float temp = x;
      x = c * x - s * y;
      y = s * temp + c * y;
    }
    gl.glEnd();
  }
  gl.glPopMatrix();
}
 

@Override
public void display(GLAutoDrawable drawable) {

    final GL2 gl = drawable.getGL().getGL2();
    gl.glTranslatef(0f, 0f, -2.5f);

    //drawing edge1.....
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(-0.75f, 0f, 0);
    gl.glVertex3f(0f, -0.75f, 0);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(-0.75f, 0f, 3f); // 3 units into the window
    gl.glVertex3f(0f, -0.75f, 3f);
    gl.glEnd();

    //top
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(-0.75f, 0f, 0);
    gl.glVertex3f(-0.75f, 0f, 3f);
    gl.glEnd();

    // bottom
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0f, -0.75f, 0);
    gl.glVertex3f(0f, -0.75f, 3f);
    gl.glEnd();

    // edge 2....
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0f, -0.75f, 0);
    gl.glVertex3f(0.75f, 0f, 0);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0f, -0.75f, 3f);
    gl.glVertex3f(0.75f, 0f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0f, -0.75f, 0);
    gl.glVertex3f(0f, -0.75f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.75f, 0f, 0);
    gl.glVertex3f(0.75f, 0f, 3f);
    gl.glEnd();

    //Edge 3.............
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.0f, 0.75f, 0);
    gl.glVertex3f(-0.75f, 0f, 0);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.0f, 0.75f, 3f);
    gl.glVertex3f(-0.75f, 0f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.0f, 0.75f, 0);
    gl.glVertex3f(0.0f, 0.75f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(-0.75f, 0f, 0);
    gl.glVertex3f(-0.75f, 0f, 3f);
    gl.glEnd();

    //final edge
    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.75f, 0f, 0);
    gl.glVertex3f(0.0f, 0.75f, 0);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.75f, 0f, 3f);
    gl.glVertex3f(0.0f, 0.75f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.75f, 0f, 0);
    gl.glVertex3f(0.75f, 0f, 3f);
    gl.glEnd();

    gl.glBegin(GL2.GL_LINES);
    gl.glVertex3f(0.0f, 0.75f, 0);
    gl.glVertex3f(0.0f, 0.75f, 3f);
    gl.glEnd();
}