add extra logging for shader linking errors

src/GLDebug.h

@@ -8,6 +8,7 @@
 
 
 void dumpShader(GLuint prog_id);
+const char* glEnumToString(GLenum e);
 void openglDebugCallback(GLenum source,
 	GLenum type,
 	GLuint id,
@@ -59,6 +60,14 @@ glEnumToString(GLenum e)
 		case GL_DEBUG_SEVERITY_NOTIFICATION:
 			return "GL_DEBUG_SEVERITY_NOTIFICATION";
 
+		case GL_NO_ERROR: return "GL_NO_ERROR";
+		case GL_INVALID_ENUM: return "GL_INVALID_ENUM";
+		case GL_INVALID_VALUE: return "GL_INVALID_VALUE";
+		case GL_INVALID_OPERATION: return "GL_INVALID_OPERATION";
+		case GL_INVALID_FRAMEBUFFER_OPERATION:
+			return "GL_INVALID_FRAMEBUFFER_OPERATION";
+		case GL_OUT_OF_MEMORY: return "GL_OUT_OF_MEMORY";
+
 		default: return "???";
 	}
 }

src/shader.cpp

@@ -371,7 +371,6 @@ compileAndLinkShader(ShaderProgram* shader,
 		glShaderSource(vs_id, 1, &vert_src, NULL);
 		glShaderSource(fs_id, 1, &frag_src, NULL);
 
-		// TODO: add a glError to string function in GLDebug.h
 		glCompileShader(vs_id);
 		assert(glGetError() == GL_NO_ERROR);
 		glCompileShader(fs_id);
@@ -385,6 +384,16 @@ compileAndLinkShader(ShaderProgram* shader,
 		GLint is_linked = 0;
 		glGetProgramiv(shader->prog_id, GL_LINK_STATUS, &is_linked);
 
+		// NOTE: log shader linking errors
+		if (is_linked != GL_TRUE) {
+			const u32 max_len = 512;
+			char err_str[max_len];
+			i32 write_len;
+			glGetProgramInfoLog(
+				shader->prog_id, max_len, &write_len, &err_str[0]);
+			LOGF(Error, "Info Log: %s\n", err_str);
+		}
+
 		return (is_linked == GL_TRUE);
 	}