Add initial GLX context management

gl-natives/pom.xml

@@ -12,4 +12,31 @@
   <packaging>nar</packaging>
 
   <name>OpenRS2 GL Natives</name>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>com.github.maven-nar</groupId>
+        <artifactId>nar-maven-plugin</artifactId>
+        <configuration>
+          <linker>
+            <sysLibs>
+              <sysLib>
+                <type>shared</type>
+                <name>GL</name>
+              </sysLib>
+              <sysLib>
+                <type>shared</type>
+                <name>GLX</name>
+              </sysLib>
+              <sysLib>
+                <type>shared</type>
+                <name>jawt</name>
+              </sysLib>
+            </sysLibs>
+          </linker>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
 </project>

gl-natives/src/main/c/jaggl.c

@@ -0,0 +1,258 @@
+#include "jaggl_context.h"
+#include "jaggl_opengl.h"
+
+#include <GL/glx.h>
+#include <jawt.h>
+#include <jawt_md.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+#define JAGGL_LOCK(env) \
+	JAWT awt = { .version = JAWT_VERSION_1_4 }; \
+	bool awt_valid = JAWT_GetAWT(env, &awt); \
+	if (awt_valid) { \
+		awt.Lock(env); \
+	}
+
+#define JAGGL_UNLOCK(env) \
+	if (awt_valid) { \
+		awt.Unlock(env); \
+	}
+
+static Display *jaggl_display;
+static XVisualInfo *jaggl_visual_info;
+static VisualID jaggl_visual_id;
+static GLXContext jaggl_context;
+static GLXDrawable jaggl_drawable;
+static int jaggl_alpha_bits;
+static bool jaggl_double_buffered;
+
+static PFNGLXSWAPINTERVALSGIPROC jaggl_glXSwapIntervalSGI;
+
+static void jaggl_init_proc_table(void) {
+	jaggl_glXSwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC) glXGetProcAddressARB((const GLubyte *) "glXSwapIntervalSGI");
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_createContext(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	GLXContext current = glXGetCurrentContext();
+	if (current) {
+		glXMakeCurrent(jaggl_display, None, NULL);
+	}
+
+	if (jaggl_context) {
+		glXDestroyContext(jaggl_display, jaggl_context);
+		jaggl_context = NULL;
+	}
+
+	jaggl_context = glXCreateContext(jaggl_display, jaggl_visual_info, NULL, True);
+
+	JAGGL_UNLOCK(env);
+	return jaggl_context != NULL;
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_releaseContext(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	jboolean result = JNI_TRUE;
+
+	GLXContext current = glXGetCurrentContext();
+	if (current) {
+		result = (jboolean) glXMakeCurrent(jaggl_display, None, NULL);
+	}
+
+	JAGGL_UNLOCK(env);
+	return result;
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_destroy(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	GLXContext current = glXGetCurrentContext();
+	if (current) {
+		glXMakeCurrent(jaggl_display, None, NULL);
+	}
+
+	if (jaggl_context) {
+		glXDestroyContext(jaggl_display, jaggl_context);
+		jaggl_context = NULL;
+	}
+
+	if (jaggl_visual_info) {
+		XFree(jaggl_visual_info);
+		jaggl_visual_info = NULL;
+	}
+
+	jaggl_display = None;
+
+	JAGGL_UNLOCK(env);
+	return JNI_TRUE;
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_swapBuffers(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	if (jaggl_double_buffered) {
+		glXSwapBuffers(jaggl_display, jaggl_drawable);
+	} else {
+		glFlush();
+	}
+
+	JAGGL_UNLOCK(env);
+	return JNI_TRUE;
+}
+
+JNIEXPORT jint JNICALL Java_jaggl_context_getLastError(JNIEnv *env, jclass cls) {
+	return 0;
+}
+
+JNIEXPORT void JNICALL Java_jaggl_context_setSwapInterval(JNIEnv *env, jclass cls, jint interval) {
+	JAGGL_LOCK(env);
+
+	if (jaggl_glXSwapIntervalSGI) {
+		jaggl_glXSwapIntervalSGI(interval);
+	}
+
+	JAGGL_UNLOCK(env);
+}
+
+JNIEXPORT jstring JNICALL Java_jaggl_context_getExtensionsString(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	const char *extensions_str = glXQueryExtensionsString(jaggl_display, jaggl_visual_info->screen);
+	jstring extensions = (*env)->NewStringUTF(env, extensions_str);
+
+	JAGGL_UNLOCK(env);
+	return extensions;
+}
+
+JNIEXPORT jint JNICALL Java_jaggl_context_getAlphaBits(JNIEnv *env, jclass cls) {
+	return jaggl_alpha_bits;
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_choosePixelFormat1(JNIEnv *env, jclass cls, jobject component, jint num_samples, jint alpha_bits) {
+	JAGGL_LOCK(env);
+
+	jboolean result = JNI_FALSE;
+
+	if (!awt_valid) {
+		goto awt_unlock;
+	}
+
+	JAWT_DrawingSurface *ds = awt.GetDrawingSurface(env, component);
+	if (!ds) {
+		goto awt_unlock;
+	}
+
+	jint lock_result = ds->Lock(ds);
+	if ((lock_result & JAWT_LOCK_ERROR) != 0) {
+		goto ds_free;
+	}
+
+	JAWT_DrawingSurfaceInfo *dsi = ds->GetDrawingSurfaceInfo(ds);
+	if (!dsi) {
+		goto ds_unlock;
+	}
+
+	JAWT_X11DrawingSurfaceInfo *platformInfo = (JAWT_X11DrawingSurfaceInfo *) dsi->platformInfo;
+	if (!platformInfo) {
+		goto dsi_free;
+	}
+
+	jaggl_display = platformInfo->display;
+	jaggl_drawable = platformInfo->drawable;
+	jaggl_visual_id = platformInfo->visualID;
+
+	if (!glXQueryExtension(jaggl_display, NULL, NULL)) {
+		goto dsi_free;
+	}
+
+	XWindowAttributes window_attribs;
+	if (XGetWindowAttributes(jaggl_display, jaggl_drawable, &window_attribs)) {
+		XVisualInfo visual_info_template = { .visualid = window_attribs.visual->visualid };
+		int matches;
+		jaggl_visual_info = XGetVisualInfo(jaggl_display, VisualIDMask, &visual_info_template, &matches);
+		if (jaggl_visual_info) {
+			int value;
+			glXGetConfig(jaggl_display, jaggl_visual_info, GLX_DOUBLEBUFFER, &value);
+			jaggl_double_buffered = value;
+
+			glXGetConfig(jaggl_display, jaggl_visual_info, GLX_ALPHA_SIZE, &value);
+			jaggl_alpha_bits = value;
+
+			result = JNI_TRUE;
+			goto dsi_free;
+		}
+	}
+
+	for (int i = 0; i < 2; i++) {
+		bool double_buffered = i == 0;
+		int attribs[] = {
+			GLX_RGBA,
+			GLX_RED_SIZE,
+			8,
+			GLX_GREEN_SIZE,
+			8,
+			GLX_BLUE_SIZE,
+			8,
+			GLX_ALPHA_SIZE,
+			alpha_bits,
+			GLX_DEPTH_SIZE,
+			24,
+			GLX_SAMPLE_BUFFERS,
+			num_samples ? True : False,
+			GLX_SAMPLES,
+			num_samples,
+			double_buffered ? GLX_DOUBLEBUFFER : None,
+			None
+		};
+		jaggl_visual_info = glXChooseVisual(jaggl_display, DefaultScreen(jaggl_display), attribs);
+		if (jaggl_visual_info) {
+			jaggl_double_buffered = double_buffered;
+			jaggl_alpha_bits = alpha_bits;
+
+			result = JNI_TRUE;
+			goto dsi_free;
+		}
+	}
+
+dsi_free:
+	ds->FreeDrawingSurfaceInfo(dsi);
+ds_unlock:
+	ds->Unlock(ds);
+ds_free:
+	awt.FreeDrawingSurface(ds);
+awt_unlock:
+	JAGGL_UNLOCK(env);
+	return result;
+}
+
+JNIEXPORT jboolean JNICALL Java_jaggl_context_makeCurrent1(JNIEnv *env, jclass cls) {
+	JAGGL_LOCK(env);
+
+	jboolean result = JNI_FALSE;
+
+	if (!jaggl_context) {
+		goto done;
+	}
+
+	GLXContext current = glXGetCurrentContext();
+	if (jaggl_context == current) {
+		result = JNI_TRUE;
+		goto done;
+	}
+
+	glXMakeCurrent(jaggl_display, None, NULL);
+
+	if (!glXMakeCurrent(jaggl_display, jaggl_drawable, jaggl_context)) {
+		goto done;
+	}
+
+	jaggl_init_proc_table();
+	result = JNI_TRUE;
+
+done:
+	JAGGL_UNLOCK(env);
+	return result;
+}