OpenGL ES 2.0：填充球体而不是线框

Question

So finally by following some other posts etc I have created a sphere in OpenGL 2.0 (Android)

However it is currently rendering as a wireframe instead of being filled in.

Draw code

public void draw()
    {
        // Set our per-vertex lighting program.
        GLES20.glUseProgram(mProgramHandle);

        // Set program handles for drawing.
        mRenderer.mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_MVPMatrix");
        mRenderer.mMVMatrixHandle = GLES20.glGetUniformLocation(mProgramHandle, "u_MVMatrix");
        mNormalHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Normal");
        mPositionHandle = GLES20.glGetAttribLocation(mProgramHandle, "a_Position");
        mColorHandle = GLES20.glGetUniformLocation(mProgramHandle, "v_Color");

        // Translate the cube into the screen.
        Matrix.setIdentityM(mRenderer.mModelMatrix, 0); 
        Matrix.translateM(mRenderer.mModelMatrix, 0, position.x, position.y, position.z);
        Matrix.scaleM(mRenderer.mModelMatrix, 0, scale.x, scale.y, scale.z);

        Matrix.rotateM(mRenderer.mModelMatrix, 0, rotation.x, 1, 0,0);
        Matrix.rotateM(mRenderer.mModelMatrix, 0, rotation.y, 0, 1,0);
        Matrix.rotateM(mRenderer.mModelMatrix, 0, rotation.z, 0, 0,1);

        float color[] = { 0.0f, 0.0f, 1.0f, 1.0f };

        // Set color for drawing the triangle
        GLES20.glUniform4fv(mColorHandle, 1, color, 0);

        GLES20.glEnableVertexAttribArray(mPositionHandle);
        GLES20.glVertexAttribPointer(mPositionHandle, 3, GLES20.GL_FLOAT, false, BYTES_PER_VERTEX, vertexBuffer); 

        GLES20.glEnableVertexAttribArray(mNormalHandle);                

        // This multiplies the view matrix by the model matrix, and stores the result in the MVP matrix
        // (which currently contains model * view).
        Matrix.multiplyMM(mRenderer.mMVPMatrix, 0, mRenderer.mViewMatrix, 0, mRenderer.mModelMatrix, 0);   

        // Pass in the modelview matrix.
        GLES20.glUniformMatrix4fv(mRenderer.mMVMatrixHandle, 1, false, mRenderer.mMVPMatrix, 0);                

        // This multiplies the modelview matrix by the projection matrix, and stores the result in the MVP matrix
        // (which now contains model * view * projection).        
        Matrix.multiplyMM(mTemporaryMatrix, 0, mRenderer.mProjectionMatrix, 0, mRenderer.mMVPMatrix, 0);
        System.arraycopy(mTemporaryMatrix, 0, mRenderer.mMVPMatrix, 0, 16);

        // Pass in the combined matrix.
        GLES20.glUniformMatrix4fv(mRenderer.mMVPMatrixHandle, 1, false, mRenderer.mMVPMatrix, 0);

        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, vertexCount);    
        //GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertexCount);

    }

Sphere creation code

private void generateSphereCoords(float radius, int stacks, int slices)
    {
        for (int stackNumber = 0; stackNumber <= stacks; ++stackNumber)
        {
            for (int sliceNumber = 0; sliceNumber < slices; ++sliceNumber)
            {
                float theta = (float) (stackNumber * Math.PI / stacks);
                float phi = (float) (sliceNumber * 2 * Math.PI / slices);
                float sinTheta = FloatMath.sin(theta);
                float sinPhi = FloatMath.sin(phi);
                float cosTheta = FloatMath.cos(theta);
                float cosPhi = FloatMath.cos(phi);
                vertexBuffer.put(new float[]{radius * cosPhi * sinTheta, radius * sinPhi * sinTheta, radius * cosTheta});
            }
        }

        for (int stackNumber = 0; stackNumber < stacks; ++stackNumber)
        {
            for (int sliceNumber = 0; sliceNumber <= slices; ++sliceNumber)
            {
                indexBuffer.put((short) ((stackNumber * slices) + (sliceNumber % slices)));
                indexBuffer.put((short) (((stackNumber + 1) * slices) + (sliceNumber % slices)));
            }
        }
    }

Any ideas how I can make this 1 full colour instead of a wireframe?

In the fragment shader I have

precision mediump float;        // Set the default precision to medium. We don't need as high of a 
                                // precision in the fragment shader.
uniform vec3 u_LightPos;        // The position of the light in eye space.
uniform sampler2D u_Texture;    // The input texture.

uniform vec4 v_Color;
varying vec3 v_Position;        // Interpolated position for this fragment.
varying vec3 v_Normal;          // Interpolated normal for this fragment.

// The entry point for our fragment shader.
void main()                         
{                              
    // Will be used for attenuation.
    float distance = length(u_LightPos - v_Position);                  

    // Get a lighting direction vector from the light to the vertex.
    vec3 lightVector = normalize(u_LightPos - v_Position);                  

    // Calculate the dot product of the light vector and vertex normal. If the normal and light vector are
    // pointing in the same direction then it will get max illumination.
    float diffuse = max(dot(v_Normal, lightVector), 0.0);                                                                                 

    // Add attenuation. 
    diffuse = diffuse * (1.0 / (1.0 + (0.25 * distance)));

    // Add ambient lighting
    diffuse = diffuse + 0.7;  

    gl_FragColor = v_Color;                                     
  }  

Vertex

uniform mat4 u_MVPMatrix;       // A constant representing the combined model/view/projection matrix.                  
uniform mat4 u_MVMatrix;        // A constant representing the combined model/view matrix.              

attribute vec4 a_Position;      // Per-vertex position information we will pass in.                             
attribute vec3 a_Normal;        // Per-vertex normal information we will pass in.       

varying vec3 v_Position;        // This will be passed into the fragment shader.                            
varying vec3 v_Normal;          // This will be passed into the fragment shader.  

// The entry point for our vertex shader.  
void main()                                                     
{         

    // Transform the vertex into eye space.     
    v_Position = vec3(u_MVMatrix * a_Position);                                                

    // Transform the normal's orientation into eye space.
    v_Normal = vec3(u_MVMatrix * vec4(a_Normal, 0.0));

    // gl_Position is a special variable used to store the final position.
    // Multiply the vertex by the matrix to get the final point in normalized screen coordinates.
    gl_Position = u_MVPMatrix * a_Position;                               
}                                                          

Answer 1

It looks like you are calculating vertex indices in your setup code, but not using them. Consider using glDrawElements instead of glDrawArrays.

It also looks like you are half way between using GL_TRIANGLE_STRIP (one new index per triangle after the first triangle) and GL_TRIANGLES (three indices per triangle). You will probably find it easier to use GL_TRIANGLES.