Start work on OpenGL bindings

kitty/__init__.py

@@ -1,5 +1 @@
-import OpenGL
 
-# PyOpenGL error checking is extremely slow, so disable it, since by default it
-# runs for every call into the OpenGL API
-OpenGL.ERROR_CHECKING = False

kitty/data-types.c

@@ -9,24 +9,26 @@
 extern int init_LineBuf(PyObject *);
 extern int init_Cursor(PyObject *);
 extern int init_Line(PyObject *);
+#include "gl.h"
 
 static PyMethodDef module_methods[] = {
+    GL_METHODS
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
 
+
 static struct PyModuleDef module = {
-   PyModuleDef_HEAD_INIT,
-   "fast_data_types",   /* name of module */
-   NULL, 
-   -1,       
-   module_methods
+   .m_base = PyModuleDef_HEAD_INIT,
+   .m_name = "fast_data_types",   /* name of module */
+   .m_doc = NULL, 
+   .m_size = -1,       
+   .m_methods = module_methods
 };
 
 PyMODINIT_FUNC
 PyInit_fast_data_types(void) {
     PyObject *m;
 
-
     m = PyModule_Create(&module);
     if (m == NULL) return NULL;
 

kitty/develop_gl.py

@@ -9,6 +9,7 @@ import sys
 from kitty.shaders import ShaderProgram, GL_VERSION, Sprites, check_for_required_extensions
 from kitty.fonts import set_font_family, cell_size
 from kitty.char_grid import calculate_vertices, cell_shader
+from kitty.fast_data_types import glViewport, enable_automatic_opengl_error_checking
 
 
 def rectangle_uv(left=0, top=0, right=1, bottom=1):
@@ -37,7 +38,7 @@ class Renderer:
         self.do_layout()
 
     def on_resize(self, window, w, h):
-        gl.glViewport(0, 0, w, h)
+        glViewport(0, 0, w, h)
         self.w, self.h = w, h
         self.do_layout()
 
@@ -137,6 +138,7 @@ def main():
     glfw.glfwSetErrorCallback(on_error)
     if not glfw.glfwInit():
         raise SystemExit('GLFW initialization failed')
+    enable_automatic_opengl_error_checking(True)
     set_font_family('monospace', 144)
     try:
         _main()

kitty/gl.h

@@ -0,0 +1,63 @@
+/*
+ * gl.c
+ * Copyright (C) 2016 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include "data-types.h"
+#include <GL/glew.h>
+
+#define STRINGIFY(x) #x
+#define METH(name, argtype) {STRINGIFY(gl##name), (PyCFunction)name, argtype, NULL},
+
+static int _enable_error_checking = 1;
+
+#define SET_GL_ERR \
+    switch(glGetError()) { \
+        case GL_NO_ERROR: break; \
+        case GL_INVALID_ENUM: \
+            PyErr_SetString(PyExc_ValueError, "An enum value is invalid (GL_INVALID_ENUM)"); break; \
+        case GL_INVALID_VALUE: \
+            PyErr_SetString(PyExc_ValueError, "An numeric value is invalid (GL_INVALID_VALUE)"); break; \
+        case GL_INVALID_OPERATION: \
+            PyErr_SetString(PyExc_ValueError, "This operation is not allowed in the current state (GL_INVALID_OPERATION)"); break; \
+        case GL_INVALID_FRAMEBUFFER_OPERATION: \
+            PyErr_SetString(PyExc_ValueError, "The framebuffer object is not complete (GL_INVALID_FRAMEBUFFER_OPERATION)"); break; \
+        case GL_OUT_OF_MEMORY: \
+            PyErr_SetString(PyExc_MemoryError, "There is not enough memory left to execute the command. (GL_OUT_OF_MEMORY)"); break; \
+        case GL_STACK_UNDERFLOW: \
+            PyErr_SetString(PyExc_OverflowError, "An attempt has been made to perform an operation that would cause an internal stack to underflow. (GL_STACK_UNDERFLOW)"); break; \
+        case GL_STACK_OVERFLOW: \
+            PyErr_SetString(PyExc_OverflowError, "An attempt has been made to perform an operation that would cause an internal stack to underflow. (GL_STACK_UNDERFLOW)"); break; \
+        default: \
+            PyErr_SetString(PyExc_RuntimeError, "An unknown OpenGL error occurred."); break; \
+    }
+
+#define CHECK_ERROR if (_enable_error_checking) { SET_GL_ERR; if (PyErr_Occurred()) return NULL; }
+
+static PyObject*
+enable_automatic_error_checking(PyObject UNUSED *self, PyObject *val) {
+    _enable_error_checking = PyObject_IsTrue(val) ? 1 : 0;
+    Py_RETURN_NONE;
+}
+
+static PyObject* 
+Viewport(PyObject UNUSED *self, PyObject *args) {
+    unsigned int x, y, w, h;
+    if (!PyArg_ParseTuple(args, "IIII", &x, &y, &w, &h)) return NULL;
+    glViewport(x, y, w, h);
+    CHECK_ERROR;
+    Py_RETURN_NONE;
+}
+
+static PyObject* 
+CheckError(PyObject UNUSED *self) {
+    CHECK_ERROR; Py_RETURN_NONE;
+}
+
+#define GL_METHODS \
+    {"enable_automatic_opengl_error_checking", (PyCFunction)enable_automatic_error_checking, METH_O, NULL}, \
+    METH(Viewport, METH_VARARGS) \
+    METH(CheckError, METH_NOARGS) \
+

setup.py

@@ -21,6 +21,10 @@ version = tuple(map(int, re.search(r"^version = \((\d+), (\d+), (\d+)\)", consta
 cflags = ldflags = cc = ldpaths = None
 
 
+def pkg_config(pkg, *args):
+    return shlex.split(subprocess.check_output(['pkg-config', pkg] + list(args)).decode('utf-8'))
+
+
 def init_env():
     global cflags, ldflags, cc, ldpaths
     cc = os.environ.get('CC', 'gcc')
@@ -34,11 +38,12 @@ def init_env():
     ldflags += shlex.split(os.environ.get('LDFLAGS', ''))
 
     cflags.append('-pthread')
+    cflags.extend(pkg_config('glew', '--cflags-only-I'))
     ldflags.append('-pthread')
     ldflags.append('-shared')
     cflags.append('-I' + sysconfig.get_config_var('CONFINCLUDEPY'))
     lib = sysconfig.get_config_var('LDLIBRARY')[3:-3]
-    ldpaths = ['-L' + sysconfig.get_config_var('LIBDIR'), '-l' + lib]
+    ldpaths = ['-L' + sysconfig.get_config_var('LIBDIR'), '-l' + lib] + pkg_config('glew', '--libs')
 
     try:
         os.mkdir(build_dir)