当我启动项目时，我会在预期的青色背景中呈现一个不祥的黑色四边形。我已经确定纹理坐标正在使用片段着色器中注释掉的代码行正确插值。我已经尝试了许多不同的加载纹理的方法，并且总是得到相同的结果。加载4像素纹理的临时位代码是从书中的示例中逐字复制的。但是我也把这个包括在内，以防我疏忽了。
我试图删除无效的代码。但是，我对此仍然很陌生，并不断学习大部分代码的全部含义。此外，大部分代码都是根据不同来源改编的。所以，我为混乱，不一致的变量命名和冗长而道歉。我觉得这个问题出现在前几行。提前感谢您的所有见解。即使是关于我如何进行调试的任何信息都将受到赞赏;在处理这个项目时出现问题时，我感到非常黑暗。
画框：
public void onDrawFrame(GL10 gl)
{
GLES20.glClearColor(0.0f, 1.0f, 1.0f, 1.0f);
GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
update();
GLES20.glUseProgram(mProgramHandle);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureHandle);
GLES20.glUniform1i(mTextureUniformHandle, 0);
//For some reason I think the problem is in this area
Matrix.setIdentityM(mModelMatrix, 0);
quadVerts.position(mPositionOffset);
GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false, mStrideBytes, quadVerts);
GLES20.glEnableVertexAttribArray(mPositionHandle);
quadVerts.position(mColorOffset);
GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, GLES20.GL_FLOAT, false, mStrideBytes, quadVerts);
GLES20.glEnableVertexAttribArray(mColorHandle);
GLES20.glVertexAttribPointer(mTextureCoordinateHandle, 2, GLES20.GL_FLOAT, false, 0, quadTex);
GLES20.glEnableVertexAttribArray(2);
Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);
Matrix.multiplyMM(mMVPMatrix, 0, mOrthographicMatrix, 0, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_FAN, 0, 4);
//...
checkGlError("on draw frame: ");
}
表面改变：
public void onSurfaceChanged(GL10 glUnused, int width, int height)
{
GLES20.glViewport(0, 0, width, height);
w = width;
h = height;
final float near = 1.0f;
final float far = 10.0f;
Matrix.orthoM(mOrthographicMatrix, 0, 0, width, 0, height, near, far);
float[] pVertsData =
{
20.0f, 20.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f,
(float) width- 20.0f, 20.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f,
(float) width - 20.0f, (float) height - 20.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f,
20.0f, (float) height - 20.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f
};
quadVerts = ByteBuffer.allocateDirect(pVertsData.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
quadVerts.put(pVertsData).position(0);
float texture[] =
{
0.0f, 0.0f,
1.0f, 0.0f,
1.0f, 1.0f,
0.0f, 1.0f
};
quadTex = ByteBuffer.allocateDirect(texture.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
quadTex.put(texture).position(0);
checkGlError("surface changed: ");
}
Surface Created：
public void onSurfaceCreated(GL10 glUnused, EGLConfig config)
{
mParticleSystem = new ParticleSystem();
//GLES20.glEnable(GLES20.GL_TEXTURE_2D);
if (mTextureHandle != 1)
mTextureHandle = loadGLTexture(activeContext, resourceID);
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
final float eyeX = 0.0f;
final float eyeY = 0.0f;
final float eyeZ = 1.5f;
final float lookX = 0.0f;
final float lookY = 0.0f;
final float lookZ = -5.0f;
final float upX = 0.0f;
final float upY = 1.0f;
final float upZ = 0.0f;
Matrix.setLookAtM(mViewMatrix, 0, eyeX, eyeY, eyeZ, lookX, lookY, lookZ, upX, upY, upZ);
final String vertexShader =
"uniform mat4 u_MVPMatrix; \n"
+ "attribute vec4 a_Position; \n"
+ "attribute vec4 a_Color; \n"
+ "attribute vec2 a_TexCoordinate; \n"
+ "//varying vec3 v_Position; \n"
+ "varying vec4 v_Color; \n"
+ "varying vec2 v_TexCoordinate; \n"
+ "void main() \n"
+ "{ \n"
+ " v_TexCoordinate = a_TexCoordinate; \n"
+ " v_Color = a_Color; \n"
+ " gl_Position = u_MVPMatrix \n"
+ " * a_Position; \n"
+ "} \n";
final String fragmentShader =
"precision mediump float; \n"
+ "uniform sampler2D u_Texture; \n"
+ "varying vec4 v_Color; \n"
+ "varying vec2 v_TexCoordinate; \n"
+ "void main() \n"
+ "{ \n"
+ " vec4 baseColor;"
+ " baseColor = texture2D(u_Texture, v_TexCoordinate); \n"
+ " "
+ " gl_FragColor = baseColor; \n"
+ " \n"
+ " //gl_FragColor = vec4(v_TexCoordinate.x, v_TexCoordinate.y, 0.0, 1.0); \n"
+ " //gl_FragColor = v_Color; \n"
+ "} \n";
//... Compile Shaders
int programHandle = GLES20.glCreateProgram();
if (programHandle != 0)
{
GLES20.glAttachShader(programHandle, vertexShaderHandle);
GLES20.glAttachShader(programHandle, fragmentShaderHandle);
GLES20.glBindAttribLocation(programHandle, 0, "a_Position");
GLES20.glBindAttribLocation(programHandle, 1, "a_Color");
GLES20.glBindAttribLocation(programHandle, 2, "a_TexCoordinate");
GLES20.glLinkProgram(programHandle);
final int[] linkStatus = new int[1];
GLES20.glGetProgramiv(programHandle, GLES20.GL_LINK_STATUS, linkStatus, 0);
if (linkStatus[0] == 0)
{
GLES20.glDeleteProgram(programHandle);
programHandle = 0;
}
}
if (programHandle == 0)
{
throw new RuntimeException("Error creating program.");
}
mMVPMatrixHandle = GLES20.glGetUniformLocation(programHandle, "u_MVPMatrix");
mPositionHandle = GLES20.glGetAttribLocation(programHandle, "a_Position");
mColorHandle = GLES20.glGetAttribLocation(programHandle, "a_Color");
mTextureUniformHandle = GLES20.glGetUniformLocation(programHandle, "u_Texture");
mTextureCoordinateHandle = GLES20.glGetAttribLocation(programHandle, "a_TexCoordinate");
//GLES20.glUseProgram(programHandle);
mProgramHandle = programHandle;
checkGlError("surface created: ");
}
加载纹理：
private int loadGLTexture(Context context, final int resourceId)
{
final int[] textureHandle = new int[1];
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1);
GLES20.glGenTextures(1, textureHandle, 0);
byte[] pixels =
{
(byte) 0xff, 0, 0,
0, (byte) 0xff, 0,
0, 0, (byte) 0xff,
(byte) 0xff, (byte) 0xff, 0
};
ByteBuffer pixelBuffer = ByteBuffer.allocateDirect(4*3);
pixelBuffer.put(pixels).position(0);
GLES20.glBindTexture ( GLES20.GL_TEXTURE_2D, textureHandle[0] );
GLES20.glTexImage2D ( GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGB, 2, 2, 0, GLES20.GL_RGB, GLES20.GL_UNSIGNED_BYTE, pixelBuffer );
GLES20.glTexParameteri ( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST );
GLES20.glTexParameteri ( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST );
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
}
if (textureHandle[0] == 0)
{
throw new RuntimeException("Error loading texture.");
}
checkGlError("create texture: ");
return textureHandle[0];
}
代码更新如下所示。
答案 0 :(得分：2)
最后，找到问题所在。为简单起见，我在发布的代码中删除了很多注释掉的行。其中一个是直接在“gl_FragColor = baseColor;”之前的片段着色器中的行。然而这条线没有'\ n'......所以实际上我已经注释掉了应该将纹理实际放在四边形上的线。因此，上面的代码实际上会正常运行，而我项目中的代码则不会。
答案 1 :(得分：1)
几个想法。我不知道你的问题是否在这里，但是这里有：
您没有使用glGetError进行任何错误检查（您应该这样做）。它会帮助你找到很多问题。
GLES20.glEnable(GLES20.GL_TEXTURE_2D);不是GLES2.0中的合法电话。启用GL_TEXTURE_2D仅影响已弃用的固定功能管道。这可能会产生错误，但不应该导致您的问题。
您可以尝试添加错误检查，并在有任何问题时向后报告吗？我扫描了你的代码，但到目前为止看起来非常正确。