OpenGL ES 2.0 和 OpenGL ES 3.0 的单一代码

Question

情况：Android应用程序支持两个版本的 OpenGL ES：2.0 和 3.0。差异仅在着色器中。我不想为第 2 版和第 3 版制作单独的类集，但想合并它们。即代替两个相似的类:

import android.opengl.GLES20;
class ObjectGLES20 {
    public ObjectGLES20() {
        ...
        // invoke static methods from GLES20
        int positionLink = GLES20.glGetAttribLocation(programObject, "a_position");
        int lightPositionLink = GLES20.glGetUniformLocation(programObject, "u_lightPosition");
        ...
    }
}

import android.opengl.GLES30;
class ObjectGLES30 {
    public ObjectGLES30() {
        ...
        // invoke static methods from GLES30
        int positionLink = GLES30.glGetAttribLocation(programObject, "a_position");
        int lightPositionLink = GLES30.glGetUniformLocation(programObject, "u_lightPosition");
        ...
    }
}

做这样的事情：

// define supported version OpenGL ES
if (getVersionGLES() >= 3.0 && Build.VERSION.SDK_INT >= 18) { 
    objectAll = new ObjectAll(new GLES30(), true) // use polymorphism
} else objectAll = new ObjectAll(new GLES20(), false)
...
/** @param gles - instance of GLES20 or GLES30 */
class ObjectAll {
    public ObjectAll(GLES20 gles, boolean isSupportGLES30) {
        String pathToVertexShader;
        String pathToFragmentShader;
        if (isSupportGLES30) {
            pathToVertexShader = "shaders/gles30/vertex_shader.glsl";
            pathToFragmentShader = "shaders/gles30/fragment_shader.glsl";
        } else {
            pathToVertexShader = "shaders/gles20/vertex_shader.glsl";
            pathToFragmentShader = "shaders/gles20/fragment_shader.glsl";
        }
        int programObject = linkProgram(pathToVertexShader, pathToFragmentShader);
        ...
        // invoke static methods from GLES20 or GLES30 depending on supported version
        // TIP!: static member accessed via instance reference
        int positionLink = gles.glGetAttribLocation(programObject, "a_position");
        int lightPositionLink = gles.glGetUniformLocation(programObject, 
            "u_lightPosition");
        ...
    }
}

但是这种方法（创建实例GLES）似乎不适合调用静态方法。也许还有其他选择，例如反射或其他？谢谢大家

Answer 1

But this approach seems not good for calling static methods GLES.

AndroidGLES30对象是GLES20的子类，底层nativeAPI不做这样的区分，相同的native函数会是用于两者。

我强烈怀疑这真的无关紧要，您可以安全地为 GLES20 中的函数和常量调用 GLES20.glFoo()，它对 GLES20 都可以正常工作和 GLES30 内容。

OpenGL ES 2.0 和 OpenGL ES 3.0 的单一代码

Single code for OpenGL ES 2.0 and OpenGL ES 3.0

java

android

opengl-es