From 6924ea10c4111b11eab51f0e1aa5b4a6438da7d3 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 28 Nov 2013 14:39:49 +0200
Subject: [PATCH] Use wrappers for single-value glGet* calls

Having to create temporary stack variables just for passing in the return
pointer is quite annoying.
---
 source/misc.cpp    | 15 +++++++++++++++
 source/misc.h      |  2 ++
 source/program.cpp | 23 +++++++++++------------
 source/shader.cpp  |  9 ++++-----
 source/texunit.cpp |  5 +++--
 5 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/source/misc.cpp b/source/misc.cpp
index f27fa5e2..3af18765 100644
--- a/source/misc.cpp
+++ b/source/misc.cpp
@@ -1,3 +1,4 @@
+#include <msp/gl/extensions/arb_shader_objects.h>
 #include "misc.h"
 
 namespace Msp {
@@ -33,5 +34,19 @@ int get_i(GLenum state)
 	return data;
 }
 
+int get_shader_i(unsigned id, GLenum state)
+{
+	int data;
+	glGetShaderiv(id, state, &data);
+	return data;
+}
+
+int get_program_i(unsigned id, GLenum state)
+{
+	int data;
+	glGetProgramiv(id, state, &data);
+	return data;
+}
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/misc.h b/source/misc.h
index cfefdbf2..86e09c04 100644
--- a/source/misc.h
+++ b/source/misc.h
@@ -12,6 +12,8 @@ void set(GLenum, bool);
 
 void get(GLenum, int *);
 int get_i(GLenum);
+int get_shader_i(unsigned, GLenum);
+int get_program_i(unsigned, GLenum);
 
 } // namespace GL
 } // namespace Msp
diff --git a/source/program.cpp b/source/program.cpp
index ffdd3b63..c8ce67a8 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -8,6 +8,7 @@
 #include <msp/strings/format.h>
 #include "buffer.h"
 #include "error.h"
+#include "misc.h"
 #include "program.h"
 #include "shader.h"
 
@@ -97,15 +98,13 @@ void Program::link()
 	legacy_vars = false;
 
 	glLinkProgram(id);
-	int value;
-	glGetProgramiv(id, GL_LINK_STATUS, &value);
-	if(!(linked = value))
+	linked = get_program_i(id, GL_LINK_STATUS);
+	if(!linked)
 		throw compile_error(get_info_log());
 
-	int count;
-	glGetProgramiv(id, GL_ACTIVE_UNIFORMS, &count);
+	unsigned count = get_program_i(id, GL_ACTIVE_UNIFORMS);
 	vector<UniformInfo *> uniforms_by_index(count);
-	for(int i=0; i<count; ++i)
+	for(unsigned i=0; i<count; ++i)
 	{
 		char name[128];
 		int len = 0;
@@ -132,8 +131,8 @@ void Program::link()
 			legacy_vars = true;
 	}
 
-	glGetProgramiv(id, GL_ACTIVE_ATTRIBUTES, &count);
-	for(int i=0; i<count; ++i)
+	count = get_program_i(id, GL_ACTIVE_ATTRIBUTES);
+	for(unsigned i=0; i<count; ++i)
 	{
 		char name[128];
 		int len = 0;
@@ -146,8 +145,8 @@ void Program::link()
 
 	if(ARB_uniform_buffer_object)
 	{
-		glGetProgramiv(id, GL_ACTIVE_UNIFORM_BLOCKS, &count);
-		for(int i=0; i<count; ++i)
+		count = get_program_i(id, GL_ACTIVE_UNIFORM_BLOCKS);
+		for(unsigned i=0; i<count; ++i)
 		{
 			char name[128];
 			int len;
@@ -155,6 +154,7 @@ void Program::link()
 			UniformBlockInfo &info = uniform_blocks[name];
 			info.name = name;
 
+			int value;
 			glGetActiveUniformBlockiv(id, i, GL_UNIFORM_BLOCK_DATA_SIZE, &value);
 			info.data_size = value;
 
@@ -235,8 +235,7 @@ bool Program::uniform_location_compare(const UniformInfo *uni1, const UniformInf
 
 string Program::get_info_log() const
 {
-	GLsizei len = 0;
-	glGetProgramiv(id, GL_INFO_LOG_LENGTH, &len);
+	GLsizei len = get_program_i(id, GL_INFO_LOG_LENGTH);
 	char *buf = new char[len+1];
 	glGetProgramInfoLog(id, len+1, &len, buf);
 	string log(buf, len);
diff --git a/source/shader.cpp b/source/shader.cpp
index a1c576d8..1b3455f1 100644
--- a/source/shader.cpp
+++ b/source/shader.cpp
@@ -2,6 +2,7 @@
 #include <msp/gl/extensions/arb_shader_objects.h>
 #include <msp/gl/extensions/arb_vertex_shader.h>
 #include "error.h"
+#include "misc.h"
 #include "shader.h"
 
 using namespace std;
@@ -57,16 +58,14 @@ void Shader::source(const char *str, int len)
 void Shader::compile()
 {
 	glCompileShader(id);
-	int value = 0;
-	glGetShaderiv(id, GL_COMPILE_STATUS, &value);
-	if(!(compiled = value))
+	compiled = get_shader_i(id, GL_COMPILE_STATUS);
+	if(!compiled)
 		throw compile_error(get_info_log());
 }
 
 string Shader::get_info_log() const
 {
-	GLsizei len = 0;
-	glGetShaderiv(id, GL_INFO_LOG_LENGTH, &len);
+	GLsizei len = get_shader_i(id, GL_INFO_LOG_LENGTH);
 	char *buf = new char[len+1];
 	glGetShaderInfoLog(id, len+1, &len, buf);
 	string log(buf, len);
diff --git a/source/texunit.cpp b/source/texunit.cpp
index 1129a036..714b6502 100644
--- a/source/texunit.cpp
+++ b/source/texunit.cpp
@@ -2,6 +2,7 @@
 #include <msp/gl/extensions/arb_multitexture.h>
 #include <msp/gl/extensions/arb_vertex_shader.h>
 #include "gl.h"
+#include "misc.h"
 #include "texunit.h"
 
 using namespace std;
@@ -62,9 +63,9 @@ unsigned TexUnit::get_n_units()
 	if(count<0)
 	{
 		if(ARB_vertex_shader)
-			glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &count);
+			count = get_i(GL_MAX_TEXTURE_IMAGE_UNITS);
 		else if(ARB_multitexture)
-			glGetIntegerv(GL_MAX_TEXTURE_UNITS, &count);
+			count = get_i(GL_MAX_TEXTURE_UNITS);
 		else
 			count = 1;
 	}
-- 
2.45.2