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A royalty-free, cross-platform API for full-function 2D and 3D graphics on embedded systems - including consoles, phones, appliances and vehicles.
/*
* Copyright LWJGL. All rights reserved.
* License terms: https://www.lwjgl.org/license
*/
package org.lwjgl.opengles;
import org.lwjgl.egl.*;
import org.lwjgl.system.*;
import java.nio.*;
import java.util.*;
import static java.lang.Math.*;
import static org.lwjgl.opengles.GLES20.*;
import static org.lwjgl.opengles.GLES30.*;
import static org.lwjgl.system.APIUtil.*;
import static org.lwjgl.system.Checks.*;
import static org.lwjgl.system.JNI.*;
import static org.lwjgl.system.MemoryStack.*;
import static org.lwjgl.system.MemoryUtil.*;
/**
* This class must be used before any OpenGL ES function is called. It has the following responsibilities:
*
* - Loads the OpenGL ES native library into the JVM process.
* - Creates instances of {@link GLESCapabilities} classes. A {@code GLESCapabilities} instance contains flags for functionality that is available in an
* OpenGL ES context. Internally, it also contains function pointers that are only valid in that specific OpenGL ES context.
* - Maintains thread-local state for {@code GLESCapabilities} instances, corresponding to OpenGL ES contexts that are current in those threads.
*
*
* Library lifecycle
* The OpenGL ES library is loaded automatically when this class is initialized. Set the {@link Configuration#OPENGLES_EXPLICIT_INIT} option to override
* this behavior. Manual loading/unloading can be achieved with the {@link #create} and {@link #destroy} functions. The name of the library loaded can
* be overridden with the {@link Configuration#OPENGLES_LIBRARY_NAME} option. The maximum OpenGL ES version loaded can be set with the
* {@link Configuration#OPENGLES_MAXVERSION} option. This can be useful to ensure that no functionality above a specific version is used during development.
*
* GLESCapabilities creation
* Instances of {@code GLESCapabilities} can be created with the {@link #createCapabilities} method. An OpenGL ES context must be current in the current
* thread before it is called. Calling this method is expensive, so the {@code GLESCapabilities} instance should be associated with the OpenGL ES context and
* reused as necessary.
*
* Thread-local state
* Before a function for a given OpenGL ES context can be called, the corresponding {@code GLESCapabilities} instance must be passed to the {@link
* #setCapabilities} method. The user is also responsible for clearing the current {@code GLESCapabilities} instance when the context is destroyed or made
* current in another thread.
*
* Note that the {@link #createCapabilities} method implicitly calls {@link #setCapabilities} with the newly created instance.
*/
public final class GLES {
private static final APIVersion MAX_VERSION;
private static FunctionProvider functionProvider;
private static final ThreadLocal capabilitiesTLS = new ThreadLocal<>();
private static ICD icd = new ICDStatic();
static {
Library.loadSystem(System::load, System::loadLibrary, GLES.class, Platform.mapLibraryNameBundled("lwjgl_opengles"));
MAX_VERSION = apiParseVersion(Configuration.OPENGLES_MAXVERSION);
if (!Configuration.OPENGLES_EXPLICIT_INIT.get(false)) {
create();
}
}
private GLES() {}
/** Ensures that the lwjgl_opengles shared library has been loaded. */
static void initialize() {
// intentionally empty to trigger static initializer
}
/** Loads the OpenGL ES native library, using the default library name. */
public static void create() {
SharedLibrary GLES;
switch (Platform.get()) {
case LINUX:
GLES = Library.loadNative(GLES.class, Configuration.OPENGLES_LIBRARY_NAME, "libGLESv2.so.2");
break;
case MACOSX:
GLES = Library.loadNative(GLES.class, Configuration.OPENGLES_LIBRARY_NAME, "GLESv2");
break;
case WINDOWS:
GLES = Library.loadNative(GLES.class, Configuration.OPENGLES_LIBRARY_NAME, "libGLESv2", "GLESv2");
break;
default:
throw new IllegalStateException();
}
create(GLES);
}
/**
* Loads the OpenGL ES native library, using the specified library name.
*
* @param libName the native library name
*/
public static void create(String libName) {
create(Library.loadNative(GLES.class, libName));
}
private static void create(SharedLibrary GLES) {
try {
create((FunctionProvider)new SharedLibrary.Delegate(GLES) {
@Override
public long getFunctionAddress(ByteBuffer functionName) {
long address = EGL.getFunctionProvider().getFunctionAddress(functionName);
if (address == NULL) {
address = library.getFunctionAddress(functionName);
if (address == NULL && DEBUG_FUNCTIONS) {
apiLog("Failed to locate address for GLES function " + functionName);
}
}
return address;
}
});
} catch (RuntimeException e) {
GLES.free();
throw e;
}
}
/**
* Initializes OpenGL ES with the specified {@link FunctionProvider}. This method can be used to implement custom OpenGL ES library loading.
*
* @param functionProvider the provider of OpenGL ES function addresses
*/
public static void create(FunctionProvider functionProvider) {
if (GLES.functionProvider != null) {
throw new IllegalStateException("OpenGL ES has already been created.");
}
GLES.functionProvider = functionProvider;
}
/** Unloads the OpenGL ES native library. */
public static void destroy() {
if (functionProvider == null) {
return;
}
if (functionProvider instanceof NativeResource) {
((NativeResource)functionProvider).free();
}
functionProvider = null;
}
/** Returns the {@link FunctionProvider} for the OpenGL ES native library. */
public static FunctionProvider getFunctionProvider() {
return functionProvider;
}
/**
* Sets the {@link GLESCapabilities} of the OpenGL ES context that is current in the current thread.
*
* This {@code GLESCapabilities} instance will be used by any OpenGL ES call in the current thread, until {@code setCapabilities} is called again with
* a different value.
*/
public static void setCapabilities(GLESCapabilities caps) {
capabilitiesTLS.set(caps);
ThreadLocalUtil.setEnv(caps == null ? NULL : memAddress(caps.addresses), 3);
icd.set(caps);
}
/**
* Returns the {@link GLESCapabilities} of the OpenGL ES context that is current in the current thread.
*
* @throws IllegalStateException if {@link #setCapabilities} has never been called in the current thread or was last called with a {@code null} value
*/
public static GLESCapabilities getCapabilities() {
return checkCapabilities(capabilitiesTLS.get());
}
private static GLESCapabilities checkCapabilities(GLESCapabilities caps) {
if (CHECKS && caps == null) {
throw new IllegalStateException(
"No GLESCapabilities instance set for the current thread. Possible solutions:\n" +
"\ta) Call GLES.createCapabilities() after making a context current in the current thread.\n" +
"\tb) Call GLES.setCapabilities() if a GLESCapabilities instance already exists for the current context."
);
}
return caps;
}
/**
* Creates a new {@link GLESCapabilities} instance for the OpenGL ES context that is current in the current thread.
*
* This method calls {@link #setCapabilities(GLESCapabilities)} with the new instance before returning.
*
* @return the {@code GLESCapabilities} instance
*
* @throws IllegalStateException if no OpenGL ES context is current in the current thread
*/
public static GLESCapabilities createCapabilities() {
GLESCapabilities caps = null;
try {
// We don't have a current GLESCapabilities when this method is called
// so we have to use the native bindings directly.
long GetError = functionProvider.getFunctionAddress("glGetError");
long GetString = functionProvider.getFunctionAddress("glGetString");
long GetIntegerv = functionProvider.getFunctionAddress("glGetIntegerv");
if (GetError == NULL || GetString == NULL || GetIntegerv == NULL) {
throw new IllegalStateException(
"Core OpenGL ES functions could not be found. Make sure that the OpenGL ES library has been loaded correctly."
);
}
int errorCode = callI(GetError);
if (errorCode != GL_NO_ERROR) {
apiLog(String.format("An OpenGL ES context was in an error state before the creation of its capabilities instance. Error: [0x%X]", errorCode));
}
int majorVersion;
int minorVersion;
try (MemoryStack stack = stackPush()) {
IntBuffer pi = stack.ints(0);
// Try the 3.0+ version query first
callPV(GetIntegerv, GL_MAJOR_VERSION, memAddress(pi));
if (callI(GetError) == GL_NO_ERROR && 3 <= (majorVersion = pi.get(0))) {
// We're on an 3.0+ context.
callPV(GetIntegerv, GL_MINOR_VERSION, memAddress(pi));
minorVersion = pi.get(0);
} else {
// Fallback to the string query.
long versionString = callP(GetString, GL_VERSION);
if (versionString == NULL || callI(GetError) != GL_NO_ERROR) {
throw new IllegalStateException("There is no OpenGL ES context current in the current thread.");
}
APIVersion version = apiParseVersion(memUTF8(versionString), "OpenGL ES");
majorVersion = version.major;
minorVersion = version.minor;
}
}
if (majorVersion < 2) {
throw new IllegalStateException("OpenGL ES 2.0 is required.");
}
int[] GL_VERSIONS = {
-1, // OpenGL ES 1.0 not supported
0, // OpenGL ES 2.0
2 // OpenGL ES 3.0 to 3.2
};
Set supportedExtensions = new HashSet<>(128);
int maxMajor = min(majorVersion, GL_VERSIONS.length);
if (MAX_VERSION != null) {
maxMajor = min(MAX_VERSION.major, maxMajor);
}
for (int M = 2; M <= maxMajor; M++) {
int maxMinor = GL_VERSIONS[M - 1];
if (M == majorVersion) {
maxMinor = min(minorVersion, maxMinor);
}
if (MAX_VERSION != null && M == MAX_VERSION.major) {
maxMinor = min(MAX_VERSION.minor, maxMinor);
}
for (int m = 0; m <= maxMinor; m++) {
supportedExtensions.add(String.format("GLES%d%d", M, m));
}
}
if (majorVersion < 3) {
// Parse EXTENSIONS string
String extensionsString = memASCII(check(callP(GetString, GL_EXTENSIONS)));
if (extensionsString != null) {
StringTokenizer tokenizer = new StringTokenizer(extensionsString);
while (tokenizer.hasMoreTokens()) {
supportedExtensions.add(tokenizer.nextToken());
}
}
} else {
// Use indexed EXTENSIONS
int extensionCount;
try (MemoryStack stack = stackPush()) {
IntBuffer pi = stack.ints(0);
callPV(GetIntegerv, GL_NUM_EXTENSIONS, memAddress(pi));
extensionCount = pi.get(0);
}
long GetStringi = apiGetFunctionAddress(functionProvider, "glGetStringi");
for (int i = 0; i < extensionCount; i++) {
supportedExtensions.add(memASCII(check(callP(GetStringi, GL_EXTENSIONS, i))));
}
}
caps = new GLESCapabilities(getFunctionProvider(), supportedExtensions);
} finally {
setCapabilities(caps);
}
return caps;
}
// Only used by array overloads
static GLESCapabilities getICD() {
return icd.get();
}
/** Function pointer provider. */
private interface ICD {
default void set(GLESCapabilities caps) {}
GLESCapabilities get();
}
/**
* Write-once {@link ICD}.
*
* This is the default implementation that skips the thread-local lookup. When a new GLESCapabilities is set, we compare it to the write-once
* capabilities. If different function pointers are found, we fall back to the expensive lookup.
*/
private static class ICDStatic implements ICD {
private static GLESCapabilities tempCaps;
@Override
public void set(GLESCapabilities caps) {
if (caps != null && tempCaps != null && !ThreadLocalUtil.compareCapabilities(tempCaps.addresses, caps.addresses)) {
apiLog("[WARNING] Incompatible context detected. Falling back to thread-local lookup for GLES contexts.");
icd = GLES::getCapabilities; // fall back to thread/process lookup
return;
}
if (tempCaps == null) {
tempCaps = caps;
}
}
@Override
public GLESCapabilities get() {
return WriteOnce.caps;
}
private static final class WriteOnce {
// This will be initialized the first time get() above is called
private static final GLESCapabilities caps = ICDStatic.tempCaps;
static {
if (caps == null) {
throw new IllegalStateException("No GLESCapabilities instance has been set");
}
}
}
}
}