fix build
[gltest.git] / glxbackend.cpp
index ff126eb25ed7fdf5889b357b06aa5ab5291633c6..d51e7a751daca03ba2d612e621e152e5647479ca 100644 (file)
+/* gltest - small OpenGL tearing test program
+* Copyright (C) 2012-2013 Ralf Jung <post@ralfj.de>
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation; either version 2 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*/
+
 #include "glxbackend.h"
+#include "glutil.h"
 
 #include <stdio.h>
 #include <assert.h>
 #include <GL/glxext.h>
 #include <string>
 
-/* attributes for a double buffered visual in RGBA format with at least
-* 4 bits per color */                       
-static int attrList[] =                                             
-{                                                                      
-       GLX_RGBA, GLX_DOUBLEBUFFER,
-       GLX_RED_SIZE, 4,                                                   
-       GLX_GREEN_SIZE, 4,                                                 
-       GLX_BLUE_SIZE, 4,
-       None                                                               
+#if !defined(CON_GL1) && !defined(CON_GL3)
+#error "Valid GL contexts for GLX are: GL1, GL3"
+#endif
+
+// attributes for a double buffered framebuffer in RGBA format with at least 4 bits per color
+static int configAttribs[] =                                             
+{
+    GLX_RENDER_TYPE, GLX_RGBA_BIT,
+    GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT,
+    GLX_DOUBLEBUFFER, True,
+    GLX_RED_SIZE, 4,
+    GLX_GREEN_SIZE, 4,
+    GLX_BLUE_SIZE, 4,
+    None
+};
+
+#ifdef CON_GL3
+// attributes for a GL3 context
+static int contextAttribs[] =
+{
+    GLX_CONTEXT_MAJOR_VERSION_ARB,               3,
+    GLX_CONTEXT_MINOR_VERSION_ARB,               0,
+    GLX_CONTEXT_FLAGS_ARB,                       GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB,
+    None
 };
+#endif
 
 VisualID GLXBackend::initialize(Display *display)
 {
-       if (this->display == NULL) { // this implies that the context is also unitialized
-               this->display = display;
-               // debugging: show version information
-               int glxMajor, glxMinor;
-               glXQueryVersion(display, &glxMajor, &glxMinor);
-               printf("Using GLX version %d.%d\n", glxMajor, glxMinor);
-               // check for swap control functions
-               const char *extensions = glXQueryExtensionsString(display, DefaultScreen(display));
-               if (std::string(extensions).find("GLX_MESA_swap_control") != std::string::npos) {
-                       funSwapIntervalMesa = (PFNGLXSWAPINTERVALMESAPROC)glXGetProcAddress((const GLubyte*)"glXSwapIntervalMESA");
-                       if (funSwapIntervalMesa) printf("glXSwapIntervalMESA is present\n");
-               }
-               else {
-                       funSwapIntervalMesa = 0;
-               }
-               if (std::string(extensions).find("GLX_EXT_swap_control") != std::string::npos) {
-                       funSwapIntervalExt = (PFNGLXSWAPINTERVALEXTPROC)glXGetProcAddress((const GLubyte*)"glXSwapIntervalEXT");
-                       if (funSwapIntervalExt) printf("glXSwapIntervalEXT is present\n");
-               }
-               else {
-                       funSwapIntervalExt = 0;
-               }
-               // get the visual
-               vi = glXChooseVisual(display, DefaultScreen(display), attrList);
-       }
-       return vi->visualid;
+    if (this->display == NULL) { // this implies that the context is also unitialized
+        this->display = display;
+        // debugging: show version information
+        int glxMajor, glxMinor;
+        glXQueryVersion(display, &glxMajor, &glxMinor);
+        printf("Using GLX version: %d.%d\n", glxMajor, glxMinor);
+        if (glxMajor == 1 && glxMinor < 4) {
+            // glXChooseFBConfig and glXCreateNewContext require GLX 1.3; GLX_ARB_create_context requires GLX 1.4
+            die("Need at least GLX 1.4 to function properly\n");
+        }
+        // check for extension-based functions
+        funSwapIntervalMesa = (PFNGLXSWAPINTERVALMESAPROC)resolveGLXFunction("GLX_MESA_swap_control", "glXSwapIntervalMESA");
+        funSwapIntervalExt = (PFNGLXSWAPINTERVALEXTPROC)resolveGLXFunction("GLX_EXT_swap_control", "glXSwapIntervalEXT");
+        funCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)resolveGLXFunction("GLX_ARB_create_context", "glXCreateContextAttribsARB");
+        // get the first usable framebuffer configuration
+        int count = 0;
+        GLXFBConfig *configs = glXChooseFBConfig(display, DefaultScreen(display), configAttribs, &count);
+        if (count < 1) {
+            die("Failed to choose framebuffer configuration\n");
+        }
+        config = configs[0];
+        XFree(configs);
+    }
+    // return visual ID
+    XVisualInfo *vi = glXGetVisualFromFBConfig(display, config);
+    if (vi== NULL) {
+        die("The GLXFBConfig I got is invalid\n");
+    }
+    VisualID visualid = vi->visualid;
+    XFree(vi);
+    return visualid;
+}
+
+bool GLXBackend::haveGLXExtension(const std::string &name)
+{
+    assert(display != NULL);
+    std::string extensions = glXQueryExtensionsString(display, DefaultScreen(display));
+    return (std::string(" "+extensions+" ").find(" "+name+" ") != std::string::npos);
+}
+
+T_proc GLXBackend::resolveGLXFunction(const char *extension, const char *function)
+{
+    if (!haveGLXExtension(extension)) return NULL;
+    T_proc f = glXGetProcAddress((const GLubyte*)function);
+    if (f)
+        printf("%s is supported, using it for %s\n", extension, function);
+    else
+        printf("%s is supported, but I could not find %s\n", extension, function);
+    return f;
 }
 
 void GLXBackend::createContext(Window window)
 {
-       assert(display != NULL && context == None);
-       this->window = window;
-       // create context with that window
-       context = glXCreateContext(display, vi, 0, GL_TRUE);                             
-       glXMakeCurrent(display, window, context);                                      
-       assert(glXIsDirect(display, context));
+    assert(display != NULL && context == None);
+    this->window = window;
+    // create context with that window
+#ifdef CON_GL1
+    context = glXCreateNewContext(display, config, GLX_RGBA_TYPE, NULL, GL_TRUE);
+#else
+    if (!funCreateContextAttribsARB) {
+        die("Cannot create GL3 context: GLX_ARB_create_context not supported\n");
+    }
+    context = funCreateContextAttribsARB(display, config, NULL, GL_TRUE, contextAttribs);
+#endif
+    if (!context) {
+        die("Error creating context\n");
+    }
+    glXMakeCurrent(display, window, context);                                      
+    assert(glXIsDirect(display, context));
+    printf("Using GL version: %s\n", glGetString(GL_VERSION));
+    // initialise GL utilities
+    resolveFunctionPointers((T_glGetProcAddress)glXGetProcAddress);
 }
 
 GLXBackend::~GLXBackend()
 {
-       if (display != NULL) {
-               if (context != None) {
-                       glXMakeCurrent(display, None, NULL);
-                       glXDestroyContext(display, context);
-               }
-               XFree(vi);
-       }
+    if (display != NULL) {
+        if (context != None) {
+            glXMakeCurrent(display, None, NULL);
+            glXDestroyContext(display, context);
+        }
+    }
 }
 
 void GLXBackend::swapBuffers() const
 {
-       assert(context != None); // this implies the display is also initialized
-       glXSwapBuffers(display, window);
+    assert(context != None); // this implies the display is also initialized
+    glXSwapBuffers(display, window);
 }
 
 void GLXBackend::setSwapInterval(int i) const
 {
-       assert(context != None);
-       if (funSwapIntervalExt)
-               funSwapIntervalExt(display, window, i);
-       else if (funSwapIntervalMesa)
-               funSwapIntervalMesa(i);
-       else
-               assert(false && "At least one of glXSwapIntervalMESA, glXSwapIntervalEXT must be provided by the system");
+    assert(context != None);
+    // check if swap interval value is supported
+    if (i < 0) {
+        die("Cannot set swap interval to %d, must not be negative\n", i);
+    }
+    // set it
+    if (funSwapIntervalExt)
+        funSwapIntervalExt(display, window, i);
+    else if (funSwapIntervalMesa)
+        funSwapIntervalMesa(i);
+    else {
+        die("At least one of GLX_EXT_swap_control, GLX_MESA_swap_control must be supported by the system\n");
+    }
 }