Migrate GL setup and error handling code

kitty/gl.c

@@ -49,12 +49,6 @@ static bool _enable_error_checking = 1;
 
 #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) ? true : false;
-    Py_RETURN_NONE;
-}
-
 static PyObject* 
 Viewport(PyObject UNUSED *self, PyObject *args) {
     unsigned int x, y, w, h;
@@ -165,25 +159,6 @@ CheckError(PyObject UNUSED *self) {
     CHECK_ERROR; Py_RETURN_NONE;
 }
 
-static PyObject* 
-_glewInit(PyObject UNUSED *self) {
-#ifndef __APPLE__
-    GLenum err = glewInit();
-    if (err != GLEW_OK) {
-        PyErr_Format(PyExc_RuntimeError, "GLEW init failed: %s", glewGetErrorString(err));
-        return NULL;
-    }
-#define ARB_TEST(name) \
-    if (!GLEW_ARB_##name) { \
-        PyErr_Format(PyExc_RuntimeError, "The OpenGL driver on this system is missing the required extension: ARB_%s", #name); \
-        return NULL; \
-    }
-    ARB_TEST(texture_storage);
-#undef ARB_TEST
-#endif
-    Py_RETURN_NONE;
-}
-
 static PyObject* 
 GetString(PyObject UNUSED *self, PyObject *val) {
     const unsigned char *ans = glGetString(PyLong_AsUnsignedLong(val));
@@ -805,10 +780,8 @@ check_for_extensions(PyObject UNUSED *self) {
 }
 
 static PyMethodDef module_methods[] = {
-    {"enable_automatic_opengl_error_checking", (PyCFunction)enable_automatic_error_checking, METH_O, NULL}, 
     {"copy_image_sub_data", (PyCFunction)copy_image_sub_data, METH_VARARGS, NULL}, 
     {"replace_or_create_buffer", (PyCFunction)replace_or_create_buffer, METH_VARARGS, NULL}, 
-    {"glewInit", (PyCFunction)_glewInit, METH_NOARGS, NULL}, 
     {"check_for_extensions", (PyCFunction)check_for_extensions, METH_NOARGS, NULL}, 
     {"get_uniform_block_size", (PyCFunction)get_uniform_block_size, METH_VARARGS, NULL}, 
     {"get_uniform_block_offsets", (PyCFunction)get_uniform_block_offsets, METH_VARARGS, NULL}, 

kitty/shaders.c

@@ -6,12 +6,86 @@
  */
 
 #include "data-types.h"
+#ifdef __APPLE__
+#include <OpenGL/gl3.h>
+#include <OpenGL/gl3ext.h>
+#else
+#include <GL/glew.h>
+#endif
 
-#define GL_VERSION_MAJOR 3
-#define GL_VERSION_MINOR 3
-#define GLSL_VERSION (GL_VERSION_MAJOR * 100 + GL_VERSION_MINOR * 10)
 
-enum Program { CELL_PROGRAM, CURSOR_PROGRAM, BORDERS_PROGRAM};
+// GL setup and error handling {{{
+// Required minimum OpenGL version
+#define REQUIRED_VERSION_MAJOR 3
+#define REQUIRED_VERSION_MINOR 3
+#define GLSL_VERSION (REQUIRED_VERSION_MAJOR * 100 + REQUIRED_VERSION_MINOR * 10)
+
+static inline bool
+set_error_from_gl() {
+    int code = glGetError();
+    switch(code) { 
+        case GL_NO_ERROR: return false; 
+        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_OVERFLOW)"); break; 
+        default: 
+            PyErr_Format(PyExc_RuntimeError, "An unknown OpenGL error occurred with code: %d", code); break; 
+    }
+    return true;
+}
+
+static bool _enable_error_checking = false;
+#define CHECK_ERROR if (_enable_error_checking) { if (set_error_from_gl()) return NULL; }
+
+
+static PyObject* 
+glew_init(PyObject UNUSED *self) {
+#ifndef __APPLE__
+    GLenum err = glewInit();
+    if (err != GLEW_OK) {
+        PyErr_Format(PyExc_RuntimeError, "GLEW init failed: %s", glewGetErrorString(err));
+        return NULL;
+    }
+#define ARB_TEST(name) \
+    if (!GLEW_ARB_##name) { \
+        PyErr_Format(PyExc_RuntimeError, "The OpenGL driver on this system is missing the required extension: ARB_%s", #name); \
+        return NULL; \
+    }
+    ARB_TEST(texture_storage);
+#undef ARB_TEST
+#endif
+    Py_RETURN_NONE;
+}
+// }}}
+
+enum Program { CELL_PROGRAM, CURSOR_PROGRAM, BORDERS_PROGRAM, NUM_PROGRAMS };
+
+/* static GLuint program_ids[NUM_PROGRAMS] = {0}; */
+
+
+// Python API {{{
+static PyObject*
+enable_automatic_error_checking(PyObject UNUSED *self, PyObject *val) {
+    _enable_error_checking = PyObject_IsTrue(val) ? true : false;
+    Py_RETURN_NONE;
+}
+
+static PyMethodDef module_methods[] = {
+    {"enable_automatic_opengl_error_checking", (PyCFunction)enable_automatic_error_checking, METH_O, NULL}, 
+    {"glewInit", (PyCFunction)glew_init, METH_NOARGS, NULL}, 
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
 
 bool
 init_shaders(PyObject *module) {
@@ -19,6 +93,8 @@ init_shaders(PyObject *module) {
     C(CELL_PROGRAM); C(CURSOR_PROGRAM); C(BORDERS_PROGRAM);
     C(GLSL_VERSION);
 #undef C
-    PyModule_AddObject(module, "GL_VERSION_REQUIRED", Py_BuildValue("II", GL_VERSION_MAJOR, GL_VERSION_MINOR));
+    PyModule_AddObject(module, "GL_VERSION_REQUIRED", Py_BuildValue("II", REQUIRED_VERSION_MAJOR, REQUIRED_VERSION_MINOR));
+    if (PyModule_AddFunctions(module, module_methods) != 0) return false;
     return true;
 }
+// }}}