android - 设置gl_PointSize导致的闪屏/全黑屏

Question

我正在创建一个小型坦克游戏(渲染器超过 1300 行代码)，目前正在研究游戏中的武器。武器方面的工作变得非常烦人，因为每当我设置 gl_PointSize 时，我都会注意到屏幕上出现意想不到的东西 (屏幕上闪烁或完全黑屏)。

这是如何发生的以及如何删除此(OpenGL ES 2.0 供应商:Imagination Technologies，设备:Motorola Milestone，操作系统:Android 2.3.3)。 z-fighting 会成为问题吗？

调整 setLookAtM 不会产生任何影响，消除奇怪效果的唯一方法是删除 gl_PointSize。

---

[更新]

可能是 gl_PointSize 不是问题；游戏中有一个坦克、一个房间和一盏灯，当为武器调用 glDrawArrays 时，屏幕会闪烁或完全变黑一段时间(直到我触摸并旋转坦克)鉴于武器在截锥体内。

---

    Matrix.setLookAtM(GLES20Renderer._ViewMatrix, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0);
    Matrix.frustumM(GLES20Renderer._ProjectionMatrix, 0, -ratio, ratio, -1, 1, 0.75f, 10);

---

    float[] pointVFA = {
            3.0f,3.0f,3.0f,
            -3.0f,3.0f,3.0f,
            -3.0f,-3.0f,3.0f
    };

    ByteBuffer pointVBB = ByteBuffer.allocateDirect(pointVFA.length * 4);
    pointVBB.order(ByteOrder.nativeOrder());
    GLES20Renderer._pointVFBMissile = pointVBB.asFloatBuffer();
    GLES20Renderer._pointVFBMissile.put(pointVFA);
    GLES20Renderer._pointVFBMissile.position(0);

---

private static final String _vertexShaderCodeMissiles =
        "attribute vec4 aPosition;                                                      \n"
    +   "void main() {                                                                  \n"
    +   " gl_PointSize = 15.0;                                                          \n"
    +   " gl_Position = aPosition;                                                      \n"
    +   "}                                                                              \n";
private static final String _fragmentShaderCodeMissiles =
        "#ifdef GL_FRAGMENT_PRECISION_HIGH                                              \n"
    +   "precision highp float;                                                         \n"
    +   "#else                                                                          \n"
    +   "precision mediump float;                                                       \n"
    +   "#endif                                                                         \n"
    +   "void main() {                                                                  \n"
    +   " gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);                                      \n"
    +   "}                                                                              \n";

Answer 1

尝试了所有方法去除黑屏/闪屏，(经过2周的搅动)问题终于解决了，对我来说是一个新的教训。

似乎在 OpenGL ES 2.0 中我们不能将缓冲区对象(vbo 或 ibo)与 nio 缓冲区混合使用。要么代码应该主要使用缓冲区对象，要么只使用 nio。

这是错误的代码:

    ////////////////////////////////
    // program for missiles start //
    ////////////////////////////////
    GLES20.glUseProgram(GLES20Renderer._programMissiles);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationMissiles, 3, GLES20.GL_FLOAT, false, 12, GLES20Renderer._pointVFBMissile);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationMissiles);
    GLES20.glDrawArrays(GLES20.GL_POINTS, 0, 3);
    ///////////////////////////////
    // program for missiles end  //
    ///////////////////////////////

    //////////////////////////////
    // program for player start //
    //////////////////////////////
    GLES20.glUseProgram(GLES20Renderer._programBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[0]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationBody, 3, GLES20.GL_FLOAT, false, 12, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[1]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aColorLocationBody, 4, GLES20.GL_FLOAT, false, 16, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aColorLocationBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[2]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aNormalPositionBody, 3, GLES20.GL_FLOAT, false, 0, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aNormalPositionBody);
    GLES20.glUniform3f(GLES20Renderer._uLightPositionLocationBody, GLES20Renderer._LightPosInEyeSpace[0], GLES20Renderer._LightPosInEyeSpace[1], GLES20Renderer._LightPosInEyeSpace[2]);
    GLES20.glUniformMatrix4fv(GLES20Renderer._uMVPLocationBody, 1, false, GLES20Renderer._MVPMatrixBody, 0);
    GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[3]);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, 372, GLES20.GL_UNSIGNED_SHORT, 0);

    GLES20.glUseProgram(GLES20Renderer._programNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[0]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationNozzle, 3, GLES20.GL_FLOAT, false, 12, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[1]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aColorLocationNozzle, 4, GLES20.GL_FLOAT, false, 16, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aColorLocationNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[2]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aNormalPositionNozzle, 3, GLES20.GL_FLOAT, false, 0, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aNormalPositionNozzle);
    GLES20.glUniform3f(GLES20Renderer._uLightPositionLocationNozzle, GLES20Renderer._LightPosInEyeSpace[0], GLES20Renderer._LightPosInEyeSpace[1], GLES20Renderer._LightPosInEyeSpace[2]);
    GLES20.glUniformMatrix4fv(GLES20Renderer._uMVPLocationNozzle, 1, false, GLES20Renderer._MVPMatrixNozzle, 0);
    GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[3]);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, 144, GLES20.GL_UNSIGNED_SHORT, 0);
    /////////////////////////////
    // program for player end  //
    /////////////////////////////

这是正确的代码:

    ////////////////////////////////
    // program for missiles start //
    ////////////////////////////////
    GLES20.glUseProgram(GLES20Renderer._programMissile);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._missileBuffers[0]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationMissile, 3, GLES20.GL_FLOAT, false, 12, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationMissile);
    GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, GLES20Renderer._missileBuffers[1]);
    GLES20.glDrawElements(GLES20.GL_POINTS, 3, GLES20.GL_UNSIGNED_SHORT, 0);
    ///////////////////////////////
    // program for missiles end  //
    ///////////////////////////////

    //////////////////////////////
    // program for player start //
    //////////////////////////////
    GLES20.glUseProgram(GLES20Renderer._programBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[0]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationBody, 3, GLES20.GL_FLOAT, false, 12, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[1]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aColorLocationBody, 4, GLES20.GL_FLOAT, false, 16, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aColorLocationBody);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[2]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aNormalPositionBody, 3, GLES20.GL_FLOAT, false, 0, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aNormalPositionBody);
    GLES20.glUniform3f(GLES20Renderer._uLightPositionLocationBody, GLES20Renderer._LightPosInEyeSpace[0], GLES20Renderer._LightPosInEyeSpace[1], GLES20Renderer._LightPosInEyeSpace[2]);
    GLES20.glUniformMatrix4fv(GLES20Renderer._uMVPLocationBody, 1, false, GLES20Renderer._MVPMatrixBody, 0);
    GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, GLES20Renderer._bodyBuffers[3]);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, 372, GLES20.GL_UNSIGNED_SHORT, 0);

    GLES20.glUseProgram(GLES20Renderer._programNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[0]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aPositionLocationNozzle, 3, GLES20.GL_FLOAT, false, 12, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aPositionLocationNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[1]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aColorLocationNozzle, 4, GLES20.GL_FLOAT, false, 16, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aColorLocationNozzle);
    GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[2]);
    GLES20.glVertexAttribPointer(GLES20Renderer._aNormalPositionNozzle, 3, GLES20.GL_FLOAT, false, 0, 0);
    GLES20.glEnableVertexAttribArray(GLES20Renderer._aNormalPositionNozzle);
    GLES20.glUniform3f(GLES20Renderer._uLightPositionLocationNozzle, GLES20Renderer._LightPosInEyeSpace[0], GLES20Renderer._LightPosInEyeSpace[1], GLES20Renderer._LightPosInEyeSpace[2]);
    GLES20.glUniformMatrix4fv(GLES20Renderer._uMVPLocationNozzle, 1, false, GLES20Renderer._MVPMatrixNozzle, 0);
    GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER, GLES20Renderer._nozzleBuffers[3]);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, 144, GLES20.GL_UNSIGNED_SHORT, 0);
    /////////////////////////////
    // program for player end  //
    /////////////////////////////