* Ensure to respect the texture coordinates provided by * {@link TextureFrame}.{@link TextureFrame#getTexture() getTexture()}.{@link Texture#getImageTexCoords() getImageTexCoords()}. *
* The user's shader shall be fitted for this implementation. * Assuming we use a base shader code w/o headers using ShaderCode. * (Code copied from unit test / demoTexCubeES2)
*
*
static final String[] es2_prelude = { "#version 100\n", "precision mediump float;\n" };
static final String gl2_prelude = "#version 110\n";
static final String shaderBasename = "texsequence_xxx"; // the base shader code w/o headers
static final String myTextureLookupName = "myTexture2D"; // the desired texture lookup function
private void initShader(GL2ES2 gl, TextureSequence texSeq) {
// Create & Compile the shader objects
ShaderCode rsVp = ShaderCode.create(gl, GL2ES2.GL_VERTEX_SHADER, TexCubeES2.class,
"shader", "shader/bin", shaderBasename, true);
ShaderCode rsFp = ShaderCode.create(gl, GL2ES2.GL_FRAGMENT_SHADER, TexCubeES2.class,
"shader", "shader/bin", shaderBasename, true);
// Prelude shader code w/ GLSL profile specifics [ 1. pre-proc, 2. other ]
int rsFpPos;
if(gl.isGLES2()) {
// insert ES2 version string in beginning
rsVp.insertShaderSource(0, 0, es2_prelude[0]);
rsFpPos = rsFp.insertShaderSource(0, 0, es2_prelude[0]);
} else {
// insert GL2 version string in beginning
rsVp.insertShaderSource(0, 0, gl2_prelude);
rsFpPos = rsFp.insertShaderSource(0, 0, gl2_prelude);
}
// insert required extensions as determined by TextureSequence implementation.
rsFpPos = rsFp.insertShaderSource(0, rsFpPos, texSeq.getRequiredExtensionsShaderStub());
if(gl.isGLES2()) {
// insert ES2 default precision declaration
rsFpPos = rsFp.insertShaderSource(0, rsFpPos, es2_prelude[1]);
}
// negotiate the texture lookup function name
final String texLookupFuncName = texSeq.getTextureLookupFunctionName(myTextureLookupName);
// in case a fixed lookup function is being chosen, replace the name in our code
rsFp.replaceInShaderSource(myTextureLookupName, texLookupFuncName);
// Cache the TextureSequence shader details in StringBuffer:
final StringBuilder sFpIns = new StringBuilder();
// .. declaration of the texture sampler using the implementation specific type
sFpIns.append("uniform ").append(texSeq.getTextureSampler2DType()).append(" mgl_ActiveTexture;\n");
// .. the actual texture lookup function, maybe null in case a built-in function is being used
sFpIns.append(texSeq.getTextureLookupFragmentShaderImpl());
// Now insert the TextureShader details in our shader after the given tag:
rsFp.insertShaderSource(0, "TEXTURE-SEQUENCE-CODE-BEGIN", 0, sFpIns);
// Create & Link the shader program
ShaderProgram sp = new ShaderProgram();
sp.add(rsVp);
sp.add(rsFp);
if(!sp.link(gl, System.err)) {
throw new GLException("Couldn't link program: "+sp);
}
...
*
* The above procedure might look complicated, however, it allows most flexibility and
* workarounds to also deal with GLSL bugs.
*
*/
public interface TextureSequence {
public static final String GL_OES_EGL_image_external_Required_Prelude = "#extension GL_OES_EGL_image_external : enable\n";
public static final String samplerExternalOES = "samplerExternalOES";
public static final String sampler2D = "sampler2D";
/**
* Texture holder interface, maybe specialized by implementation
* to associated related data.
*/
public static class TextureFrame {
public TextureFrame(Texture t) {
texture = t;
}
public final Texture getTexture() { return texture; }
public String toString() {
return "TextureFrame[" + texture + "]";
}
protected final Texture texture;
}
public interface TexSeqEventListener
* In case the instance is just initialized, it shall return a TextureFrame
* object with valid attributes. The texture content may be undefined
* until the first call of {@link #getNextTexture(GL, boolean)}.
*
* Implementation shall block until next frame is available if blocking is true,
* otherwise it shall return the last frame in case a new frame is not available.
*
* Shall return null in case no frame is available.
*
* #extension GL_OES_EGL_image_external : enable
*
*
* @throws IllegalStateException if instance is not initialized
*/
public String getRequiredExtensionsShaderStub() throws IllegalStateException ;
/**
* Returns either sampler2D or samplerExternalOES
* depending on {@link #getLastTexture()}.{@link TextureFrame#getTexture() getTexture()}.{@link Texture#getTarget() getTarget()}.
*
* @throws IllegalStateException if instance is not initialized
**/
public String getTextureSampler2DType() throws IllegalStateException ;
/**
* @param desiredFuncName desired lookup function name. If null or ignored by the implementation,
* a build-in name is returned.
* @return the final lookup function name
*
* @see {@link #getTextureLookupFragmentShaderImpl()}
*
* @throws IllegalStateException if instance is not initialized
*/
public String getTextureLookupFunctionName(String desiredFuncName) throws IllegalStateException ;
/**
* Returns the complete texture2D lookup function code of type
*
* vec4 funcName(in getTextureSampler2DType() image, in vec2 texCoord) {
* vec4 texColor = do_something_with(image, texCoord);
* return texColor;
* }
*
* * funcName can be negotiated and queried via {@link #getTextureLookupFunctionName(String)}. *
* Note: This function may return an empty string in case a build-in lookup * function is being chosen. If the implementation desires so, * {@link #getTextureLookupFunctionName(String)} will ignore the desired function name * and returns the build-in lookup function name. * * @see #getTextureLookupFunctionName(String) * @see #getTextureSampler2DType() * * @throws IllegalStateException if instance is not initialized */ public String getTextureLookupFragmentShaderImpl() throws IllegalStateException ; }