add event and test graphics

4 files changed, 250 insertions, 9 deletions

diff --git a/src/gl.c b/src/gl.c
new file mode 100644
index 0000000..c83ab49
--- /dev/null
+++ b/src/gl.c
@@ -0,0 +1,53 @@
+#include "../include/mgl/gl.h"
+#include <dlfcn.h>
+/*#include <GL/gl.h>*/
+#include <stdio.h>
+
+typedef struct {
+    void **func;
+    const char *name;
+} dlsym_assign;
+
+static void* dlsym_print_fail(void *handle, const char *name) {
+    dlerror();
+    void *sym = dlsym(handle, name);
+    char *err_str = dlerror();
+
+    if(!sym)
+        fprintf(stderr, "dlsym(handle, \"%s\") failed, error: %s\n", name, err_str ? err_str : "(null)");
+
+    return sym;
+}
+
+int mgl_gl_load(mgl_gl *self) {
+    const char *gl_path = "/usr/lib/libOpenGL.so.0";
+    self->handle = dlopen(gl_path, RTLD_LAZY);
+    if(!self->handle) {
+        fprintf(stderr, "dlopen(\"%s\", RTLD_LAZY) failed\n", gl_path);
+        return -1;
+    }
+
+    const dlsym_assign assign[] = {
+        { &self->glViewport, "glViewport" },
+        { &self->glClearColor, "glClearColor" },
+        { &self->glClear, "glClear" },
+        { NULL, NULL }
+    };
+
+    for(int i = 0; assign[i].func; ++i) {
+        *assign[i].func = dlsym_print_fail(self->handle, assign[i].name);
+        if(!assign[i].func) {
+            mgl_gl_unload(self);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+void mgl_gl_unload(mgl_gl *self) {
+    if(self->handle) {
+        dlclose(self->handle);
+        self->handle = NULL;
+    }
+}
diff --git a/src/glx.c b/src/glx.c
index 4a5af9d..6712947 100644
--- a/src/glx.c
+++ b/src/glx.c
@@ -1,7 +1,12 @@
 #include "../include/mgl/glx.h"
 #include <dlfcn.h>
+/*#include <GL/glx.h>*/
 #include <stdio.h>
-#include <GL/glx.h>
+
+typedef struct {
+    void **func;
+    const char *name;
+} dlsym_assign;
 
 static void* dlsym_print_fail(void *handle, const char *name) {
     dlerror();
@@ -22,10 +27,21 @@ int mgl_glx_load(mgl_glx *self) {
         return -1;
     }
 
-    self->glXGetFBConfigs = (GLXFBConfig* (*)(Display*, int, int*))dlsym_print_fail(self->handle, "glXGetFBConfigs");
-    if(!self->glXGetFBConfigs) {
-        mgl_glx_unload(self);
-        return -1;
+    const dlsym_assign assign[] = {
+        { &self->glXChooseVisual, "glXChooseVisual" },
+        { &self->glXCreateContext, "glXCreateContext" },
+        { &self->glXDestroyContext, "glXDestroyContext" },
+        { &self->glXMakeCurrent, "glXMakeCurrent" },
+        { &self->glXSwapBuffers, "glXSwapBuffers" },
+        { NULL, NULL }
+    };
+
+    for(int i = 0; assign[i].func; ++i) {
+        *assign[i].func = dlsym_print_fail(self->handle, assign[i].name);
+        if(!assign[i].func) {
+            mgl_glx_unload(self);
+            return -1;
+        }
     }
 
     return 0;
diff --git a/src/mgl.c b/src/mgl.c
index a7221d0..27d33ae 100644
--- a/src/mgl.c
+++ b/src/mgl.c
@@ -1,7 +1,26 @@
 #include "../include/mgl/mgl.h"
-#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <stdlib.h>
 #include <stdio.h>
 
+#define GLX_USE_GL 1
+#define GLX_BUFFER_SIZE 2
+#define GLX_LEVEL 3
+#define GLX_RGBA 4
+#define GLX_DOUBLEBUFFER 5
+#define GLX_STEREO 6
+#define GLX_AUX_BUFFERS 7
+#define GLX_RED_SIZE 8
+#define GLX_GREEN_SIZE 9
+#define GLX_BLUE_SIZE 10
+#define GLX_ALPHA_SIZE 11
+#define GLX_DEPTH_SIZE 12
+#define GLX_STENCIL_SIZE 13
+#define GLX_ACCUM_RED_SIZE 14
+#define GLX_ACCUM_GREEN_SIZE 15
+#define GLX_ACCUM_BLUE_SIZE	16
+#define GLX_ACCUM_ALPHA_SIZE 17
+
 static mgl_context context;
 static int init_count = 0;
 static XErrorHandler prev_xerror = NULL;
@@ -12,6 +31,46 @@ static int ignore_xerror(Display *display, XErrorEvent *ee) {
     return 0;
 }
 
+static int glx_context_init() {
+    const int attr[] = {
+        GLX_RGBA,
+        GLX_DEPTH_SIZE, 0,
+        GLX_STENCIL_SIZE, 0,
+        GLX_RED_SIZE, 8,
+        GLX_GREEN_SIZE, 8,
+        GLX_BLUE_SIZE, 8,
+        GLX_ALPHA_SIZE, 0,
+        GLX_DOUBLEBUFFER, /* TODO: Add option to turn this off? */
+        None
+    };
+
+    context.visual_info = context.glx.glXChooseVisual(context.connection, DefaultScreen(context.connection), (int*)attr);
+    if(!context.visual_info) {
+        fprintf(stderr, "glXChooseVisual failed, no appropriate visual found\n");
+        return -1;
+    }
+
+    context.glx_context = context.glx.glXCreateContext(context.connection, context.visual_info, NULL, 1);
+    if(!context.glx_context) {
+        fprintf(stderr, "glXCreateContext failed\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static void glx_context_deinit() {
+    if(context.glx_context) {
+        context.glx.glXDestroyContext(context.connection, context.glx_context);
+        context.glx_context = NULL;
+    }
+
+    if(context.visual_info) {
+        XFree(context.visual_info);
+        context.visual_info = NULL;
+    }
+}
+
 int mgl_init(void) {
     ++init_count;
     if(init_count == 1) {
@@ -23,20 +82,35 @@ int mgl_init(void) {
         }
 
         prev_xerror = XSetErrorHandler(ignore_xerror);
+
         if(mgl_glx_load(&context.glx) != 0) {
             mgl_deinit();
             return -1;
         }
+
+        if(mgl_gl_load(&context.gl) != 0) {
+            mgl_deinit();
+            return -1;
+        }
+
+        if(glx_context_init() != 0) {
+            mgl_deinit();
+            return -1;
+        }
     }
     return 0;
 }
 
 void mgl_deinit(void) {
     if(init_count == 1) {
+        glx_context_deinit();
+        mgl_gl_unload(&context.gl);
         mgl_glx_unload(&context.glx);
         XSetErrorHandler(prev_xerror);
-        XCloseDisplay(context.connection);
-        context.connection = NULL;
+        if(context.connection) {
+            XCloseDisplay(context.connection);
+            context.connection = NULL;
+        }
     }
 
     if(init_count > 0)
@@ -44,5 +118,11 @@ void mgl_deinit(void) {
 }
 
 mgl_context* mgl_get_context(void) {
+#ifndef NDEBUG
+    if(init_count == 0) {
+        fprintf(stderr, "Error: mgl_get_context was called before mgl_init\n");
+        abort();
+    }
+#endif
     return &context;
 }
diff --git a/src/window.c b/src/window.c
index 39855da..9836907 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1,13 +1,105 @@
 #include "../include/mgl/window.h"
+#include "../include/mgl/mgl.h"
+#include <X11/Xutil.h>
+#include <stdio.h>
 
-void mgl_window_init(mgl_window *self) {
+#define GL_COLOR_BUFFER_BIT 0x00004000
 
+int mgl_window_create(mgl_window *self, const char *title, int width, int height, mgl_window_callback *callback, void *userdata) {
+    return mgl_window_create_with_params(self, title, width, height, DefaultRootWindow(mgl_get_context()->connection), callback, userdata);
+}
+
+int mgl_window_create_with_params(mgl_window *self, const char *title, int width, int height, unsigned long parent_window, mgl_window_callback *callback, void *userdata) {
+    self->window = 0;
+    self->callback = *callback;
+    self->callback_userdata = userdata;
+
+    mgl_context *context = mgl_get_context();
+
+    Colormap color_map = XCreateColormap(context->connection, DefaultRootWindow(context->connection), ((XVisualInfo*)context->visual_info)->visual, AllocNone);
+    if(!color_map) {
+        fprintf(stderr, "XCreateColormap failed\n");
+        return -1;
+    }
+
+    XSetWindowAttributes window_attr;
+    window_attr.colormap = color_map;
+    window_attr.event_mask = ExposureMask | KeyPressMask;
+
+    self->window = XCreateWindow(context->connection, parent_window, 0, 0, width, height, 0, ((XVisualInfo*)context->visual_info)->depth, InputOutput, ((XVisualInfo*)context->visual_info)->visual, CWColormap | CWEventMask, &window_attr);
+    //XFreeColormap(context->connection, color_map);
+    if(!self->window) {
+        fprintf(stderr, "XCreateWindow failed\n");
+        mgl_window_deinit(self);
+        return -1;
+    }
+
+    /* TODO: Test utf8 */
+    XStoreName(context->connection, self->window, title);
+    return 0;
 }
 
 void mgl_window_deinit(mgl_window *self) {
+    mgl_context *context = mgl_get_context();
 
+    if(self->window) {
+        XDestroyWindow(context->connection, self->window);
+        self->window = 0;
+    }
+}
+
+static void mgl_window_draw(mgl_window *self) {
+    mgl_context *context = mgl_get_context();
+
+    /* TODO: Get window size from window resize event instead */
+    XWindowAttributes gwa;
+    XGetWindowAttributes(context->connection, self->window, &gwa);
+
+    context->gl.glViewport(0, 0, gwa.width, gwa.height);
+    context->gl.glClear(GL_COLOR_BUFFER_BIT);
+    context->gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+    if(self->callback.draw)
+        self->callback.draw(self, self->callback_userdata);
+    context->glx.glXSwapBuffers(context->connection, self->window);
 }
 
 void mgl_window_show(mgl_window *self) {
+    mgl_context *context = mgl_get_context();
+
+    XMapWindow(context->connection, self->window);
+    XFlush(context->connection);
+
+    /* TODO: Switch current when rendering to another window, and set current to NULL when destroying the currently selected context */
+    context->glx.glXMakeCurrent(context->connection, self->window, context->glx_context);
+    mgl_window_draw(self);
+}
+
+static void on_receive_x11_event(mgl_window *window, XEvent *xev) {
+    switch(xev->type) {
+        case Expose:
+            mgl_window_draw(window);
+            break;
+    }
+}
+
+void mgl_window_event_poll(mgl_window *self, int timeout_ms) {
+    Display *display = mgl_get_context()->connection;
+    const int x11_fd = ConnectionNumber(display);
+
+    fd_set in_fds;
+    FD_ZERO(&in_fds); /* TODO: Optimize */
+    FD_SET(x11_fd, &in_fds);
+
+    struct timeval tv;
+    tv.tv_sec = timeout_ms / 1000;
+    tv.tv_usec = (timeout_ms * 1000) - (tv.tv_sec * 1000 * 1000);
 
+    const int num_ready_fds = select(1 + x11_fd, &in_fds, NULL, NULL, &tv);
+    if(num_ready_fds > 0) {
+        XEvent xev;
+        while(XPending(display)) {
+            XNextEvent(display, &xev);
+            on_receive_x11_event(self, &xev);
+        }
+    }
 }