add osmesa example

Author: ColleagueRiley

examples/osmesa/osmesa.c

@@ -0,0 +1,34 @@
+#define RGFW_IMPLEMENTATION
+#define RGFW_PRINT_ERRORS
+#define RGFW_DEBUG
+#define RGFW_OSMESA
+#include "RGFW.h"
+#include <stdio.h>
+
+int main(void) {
+	RGFW_setClassName("RGFW Basic");
+    RGFW_window* win = RGFW_createWindow("RGFW Example Window", RGFW_RECT(500, 500, 500, 500), RGFW_allowDND | RGFW_center);
+    RGFW_window_makeCurrent(win);
+
+    while (RGFW_window_shouldClose(win) == RGFW_FALSE) {   
+        RGFW_window_eventWait(win, RGFW_waitNext);
+        while (RGFW_window_checkEvent(win) != NULL);
+
+        RGFW_window_makeCurrent(win);
+
+        glClearColor(255, 255, 255, 255);
+
+        glClear(GL_COLOR_BUFFER_BIT);
+        
+        glBegin(GL_TRIANGLES);
+            glColor3f(1, 0, 0); glVertex2f(-0.6, -0.75);
+            glColor3f(0, 1, 0); glVertex2f(0.6, -0.75);
+            glColor3f(0, 0, 1); glVertex2f(0, 0.75);
+        glEnd();
+
+        glFlush();
+        RGFW_window_swapBuffers(win);
+    }
+
+    RGFW_window_close(win);
+}