Cleanup: py-gpu error checks

Move gpu initialization checks to the start of each function instead
of mixing with argument parsing.

source/blender/python/gpu/gpu_py_api.c

@@ -49,7 +49,7 @@
 /** \name Utils to invalidate functions
  * \{ */
 
-bool bpygpu_is_initialized(void)
+bool bpygpu_is_initialized_or_error(void)
 {
 	if (!GPU_is_initialized()) {
 		PyErr_SetString(

source/blender/python/gpu/gpu_py_api.h

@@ -25,10 +25,13 @@
 #ifndef __GPU_PY_API_H__
 #define __GPU_PY_API_H__
 
-bool bpygpu_is_initialized(void);
 
 int bpygpu_ParsePrimType(PyObject *o, void *p);
 
 PyObject *BPyInit_gpu(void);
 
+bool bpygpu_is_initialized_or_error(void);
+#define BPYGPU_IS_INIT_OR_ERROR_OBJ if (UNLIKELY(!bpygpu_is_initialized_or_error())) { return NULL; } ((void)0)
+#define BPYGPU_IS_INIT_OR_ERROR_INT if (UNLIKELY(!bpygpu_is_initialized_or_error())) { return -1; } ((void)0)
+
 #endif  /* __GPU_PY_API_H__ */

source/blender/python/gpu/gpu_py_batch.c

@@ -75,6 +75,8 @@ static bool bpygpu_batch_is_program_or_error(BPyGPUBatch *self)
 
 static PyObject *bpygpu_Batch_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
+	BPYGPU_IS_INIT_OR_ERROR_OBJ;
+
 	const char *exc_str_missing_arg = "GPUBatch.__new__() missing required argument '%s' (pos %d)";
 
 	struct {
@@ -85,8 +87,7 @@ static PyObject *bpygpu_Batch_new(PyTypeObject *UNUSED(type), PyObject *args, Py
 
 	static const char *_keywords[] = {"type", "buf", "elem", NULL};
 	static _PyArg_Parser _parser = {"|$O&O!O!:GPUBatch.__new__", _keywords, 0};
-	if (!bpygpu_is_initialized() ||
-	    !_PyArg_ParseTupleAndKeywordsFast(
+	if (!_PyArg_ParseTupleAndKeywordsFast(
 	        args, kwds, &_parser,
 	        bpygpu_ParsePrimType, &params.type_id,
 	        &BPyGPUVertBuf_Type, &params.py_vertbuf,

source/blender/python/gpu/gpu_py_element.c

@@ -47,6 +47,8 @@
 
 static PyObject *bpygpu_IndexBuf_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
+	BPYGPU_IS_INIT_OR_ERROR_OBJ;
+
 	const char *error_prefix = "IndexBuf.__new__";
 	bool ok = true;
 
@@ -61,8 +63,7 @@ static PyObject *bpygpu_IndexBuf_new(PyTypeObject *UNUSED(type), PyObject *args,
 
 	static const char *_keywords[] = {"type", "seq", NULL};
 	static _PyArg_Parser _parser = {"$O&O:IndexBuf.__new__", _keywords, 0};
-	if (!bpygpu_is_initialized() ||
-	    !_PyArg_ParseTupleAndKeywordsFast(
+	if (!_PyArg_ParseTupleAndKeywordsFast(
 	        args, kwds, &_parser,
 	        bpygpu_ParsePrimType, &params.type_id,
 	        &params.seq))

source/blender/python/gpu/gpu_py_offscreen.c

@@ -88,14 +88,15 @@ static int bpygpu_offscreen_valid_check(BPyGPUOffScreen *bpygpu_ofs)
 
 static PyObject *bpygpu_offscreen_new(PyTypeObject *UNUSED(self), PyObject *args, PyObject *kwds)
 {
+	BPYGPU_IS_INIT_OR_ERROR_OBJ;
+
 	GPUOffScreen *ofs;
 	int width, height, samples = 0;
 	char err_out[256];
 
 	static const char *_keywords[] = {"width", "height", "samples", NULL};
 	static _PyArg_Parser _parser = {"ii|i:GPUOffScreen.__new__", _keywords, 0};
-	if (!bpygpu_is_initialized() ||
-	    !_PyArg_ParseTupleAndKeywordsFast(
+	if (!_PyArg_ParseTupleAndKeywordsFast(
 	        args, kwds, &_parser,
 	        &width, &height, &samples))
 	{

source/blender/python/gpu/gpu_py_shader.c

@@ -105,6 +105,8 @@ static int bpygpu_uniform_location_get(GPUShader *shader, const char *name, cons
 
 static PyObject *bpygpu_shader_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
+	BPYGPU_IS_INIT_OR_ERROR_OBJ;
+
 	struct {
 		const char *vertexcode;
 		const char *fragcode;
@@ -118,8 +120,7 @@ static PyObject *bpygpu_shader_new(PyTypeObject *UNUSED(type), PyObject *args, P
 	        "libcode", "defines", NULL};
 
 	static _PyArg_Parser _parser = {"ss|$sss:GPUShader.__new__", _keywords, 0};
-	if (!bpygpu_is_initialized() ||
-	    !_PyArg_ParseTupleAndKeywordsFast(
+	if (!_PyArg_ParseTupleAndKeywordsFast(
 	        args, kwds, &_parser,
 	        &params.vertexcode, &params.fragcode, &params.geocode,
 	        &params.libcode, &params.defines))
@@ -717,11 +718,11 @@ PyDoc_STRVAR(bpygpu_shader_from_builtin_doc,
 );
 static PyObject *bpygpu_shader_from_builtin(PyObject *UNUSED(self), PyObject *arg)
 {
+	BPYGPU_IS_INIT_OR_ERROR_OBJ;
+
 	GPUBuiltinShader shader_id;
 
-	if (!bpygpu_is_initialized() ||
-	    !bpygpu_ParseBultinShaderEnum(arg, &shader_id))
-	{
+	if (!bpygpu_ParseBultinShaderEnum(arg, &shader_id)) {
 		return NULL;
 	}