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我在这里遇到问题。我建立了一个速度为x和y的正方形弹丸，并通过像这样设置顶点位置，将实际的方形绘制到位置。glRotate更改坐标，以便矩形绘制旋转的平面
代码：
vertices.put(new float[] { x1, y1, 1, 1, 1, 1, 0.0f, 1.0f,
x2, y2, 1, 1, 1, 1, 1.0f, 1.0f,
x3, y3, 1, 1, 1, 1, 1.0f, 0.0f,
x4, y4, 1, 1, 1, 1, 0.0f, 0.0f });
// x y r g b A u|s v|t
，所有的X的是我通过在角落的位置
我再沿x & Y轴移动这个矩形（l2rArrow），并具有画面后续它：
boolean hasTranslated = false;
if (!l2rArrow.isFired) { // if the arrow has not yet been fired we render it thus
gl.glPushMatrix(); //save our state
gl.glTranslatef(l2rArrow.GetToOriginX, l2rArrow.GetToOriginY, 0f); // translate to origin 0,0,0
gl.glRotatef(LBow.getAngle(), 0f, 0f, 1f); //rotate
gl.glTranslatef(-l2rArrow.GetToOriginX, -l2rArrow.GetToOriginY, 0f); // translate to where we want to draw it
texture.bind(gl, Texture.TEXTURE_L2RARROW);
mRect = new MeshRect(l2rArrow.getMyRect());
mRect.Draw(GL10.GL_TRIANGLES, gl);
gl.glPopMatrix(); //return to saved state
} else { // the arrow has been fired so we need to render it like this and have the "camera" follow it
hasTranslated = true;
gl.glPushMatrix();
gl.glLoadIdentity();
float camX = (float) ((l2rArrow.startX - l2rArrow.PosX));
float camY = (float) ((l2rArrow.startY - l2rArrow.PosY));
if (camY > 0) { camY = 0;}
if (camX < -4800) { camX = -4800;}
gl.glTranslatef(camX, camY,0f);
l2rArrow.Update(deltaTime);
texture.bind(gl, Texture.TEXTURE_L2RARROW);
mRect = new MeshRect(l2rArrow.getMyRect());
mRect.Draw(GL10.GL_TRIANGLES, gl);
if (l2rArrow.hasCollided) {
//run collision code for detecting a hit and ending turn
}
}
这也适用。当射弹被射击时，我们会完全遵循它。现在，尽管我想让箭头指向箭头正在传播的角度。所以我需要在中途转动箭头。我尝试将这个箭头转换回0,0旋转它，然后把它放回去，但是当我把箭头放回去时，它会绘制旋转平面的坐标。
} else {
hasTranslated = true;
gl.glPushMatrix();
gl.glLoadIdentity();
float camX = (float) ((l2rArrow.startX - l2rArrow.PosX));
float camY = (float) ((l2rArrow.startY - l2rArrow.PosY));
if (camY > 0) { camY = 0;}
if (camX < -4800) { camX = -4800;}
gl.glTranslatef(camX, camY,0f);
gl.glPushMatrix();
gl.glTranslatef(l2rArrow.GetToOriginX, l2rArrow.GetToOriginY, 0f); // translate to origin 0,0,0
gl.glRotatef((float) l2rArrow.getAngle(), 0f, 0f, 1f); //rotate
gl.glTranslatef(-l2rArrow.GetToOriginX, -l2rArrow.GetToOriginY, 0f);
l2rArrow.Update(deltaTime);
texture.bind(gl, Texture.TEXTURE_L2RARROW);
mRect = new MeshRect(l2rArrow.getMyRect());
mRect.Draw(GL10.GL_TRIANGLES, gl);
gl.glPopMatrix();
if (l2rArrow.hasCollided) {
//run collision code for detecting a hit and ending turn
}
}
我明白这一点。如何旋转箭头，然后将其移回非旋转平面上的位置？
当Y = 0时，箭头休息，而现在Y = 0以旋转角度运行。