Merge pull request #425 from Echelon9/fix/SHADER_MODEL-concept-removal

OpenGL: Refactor GLSL setup and remove DirectX Shader Model concept

Author: asarium

code/cmdline/cmdline.cpp

@@ -424,7 +424,6 @@ cmdline_parm noglsl_arg("-no_glsl", NULL, AT_NONE);			// Cmdline_noglsl  -- disa
 cmdline_parm mipmap_arg("-mipmap", NULL, AT_NONE);			// Cmdline_mipmap
 cmdline_parm atiswap_arg("-ati_swap", NULL, AT_NONE);        // Cmdline_atiswap - Fix ATI color swap issue for screenshots.
 cmdline_parm no3dsound_arg("-no_3d_sound", NULL, AT_NONE);		// Cmdline_no_3d_sound - Disable use of full 3D sounds
-cmdline_parm no_glsl_models_arg("-disable_glsl_model", NULL, AT_NONE); // Cmdline_no_glsl_model_rendering -- switches model rendering to fixed pipeline
 cmdline_parm no_di_mouse_arg("-disable_di_mouse", "Disable DirectInput mouse code (Windows only)", AT_NONE); // Cmdline_no_di_mouse -- Disables directinput use for mouse control
 cmdline_parm no_drawrangeelements("-use_gldrawelements", NULL, AT_NONE); // Cmdline_drawelements -- Uses glDrawElements instead of glDrawRangeElements
 cmdline_parm keyboard_layout("-keyboard_layout", "Specify keyboard layout (qwertz or azerty)", AT_STRING);
@@ -443,7 +442,6 @@ int Cmdline_no_pbo = 0;
 int Cmdline_noglsl = 0;
 int Cmdline_ati_color_swap = 0;
 int Cmdline_no_3d_sound = 0;
-int Cmdline_no_glsl_model_rendering = 0;
 int Cmdline_no_di_mouse = 0;
 int Cmdline_drawelements = 0;
 char* Cmdline_keyboard_layout = NULL;
@@ -1542,10 +1540,6 @@ bool SetCmdlineParams()
 		Cmdline_noglsl = 1;
 	}
 
-	if (no_glsl_models_arg.found() ) {
-		Cmdline_no_glsl_model_rendering = 1;
-	}
-
 	if (fxaa_arg.found() ) {
 		Cmdline_fxaa = true;
 

code/cmdline/cmdline.h

@@ -130,7 +130,6 @@ extern int Cmdline_noglsl;
 extern int Cmdline_mipmap;
 extern int Cmdline_ati_color_swap;
 extern int Cmdline_no_3d_sound;
-extern int Cmdline_no_glsl_model_rendering;
 extern int Cmdline_no_di_mouse;
 extern int Cmdline_drawelements;
 extern char* Cmdline_keyboard_layout;

code/cutscene/oggplayer.cpp

@@ -345,7 +345,7 @@ static void OGG_video_init(theora_info *tinfo)
 		opengl_set_texture_target(GL_TEXTURE_2D);
 		opengl_tcache_get_adjusted_texture_size(g_screenWidth, g_screenHeight, &wp2, &hp2);
 
-		if(!Use_GLSL)
+		if(!is_minimum_GLSL_version())
 			use_shaders = false;
 
 		if(use_shaders) {

code/globalincs/def_files.cpp

@@ -1536,7 +1536,7 @@ char *Default_main_fragment_shader =
 "varying vec4 position;\n"
 "varying vec3 lNormal;\n"
 "\n"
-"#if SHADER_MODEL == 2\n"
+"#if __VERSION__ == 120\n"
 "  #define MAX_LIGHTS 2\n"
 "#else\n"
 "  #define MAX_LIGHTS 8\n"
@@ -1727,7 +1727,7 @@ char *Default_main_fragment_shader =
 "   float dist;\n"
 "   #pragma optionNV unroll all\n"
 "   for (int i = 0; i < MAX_LIGHTS; ++i) {\n"
-" #if SHADER_MODEL > 2\n"
+" #if __VERSION__ > 120\n"
 "      if (i > n_lights)\n"
 "         break;\n"
 " #endif\n"
@@ -1737,15 +1737,15 @@ char *Default_main_fragment_shader =
 "      lightDir = normalize(gl_LightSource[i].position.xyz);\n"
 "      float attenuation = 1.0;\n"
 " #ifndef FLAG_DEFERRED\n"
-"  #if SHADER_MODEL > 2\n"
+"  #if __VERSION__ > 120\n"
 "      if (gl_LightSource[i].position.w == 1.0) {\n"
 "  #else\n"
 "      if (gl_LightSource[i].position.w == 1.0 && i != 0) {\n"
 "  #endif\n"
 "          // Positional light source\n"
 "          dist = distance(gl_LightSource[i].position.xyz, position.xyz);\n"
 "          lightDir = (gl_LightSource[i].position.xyz - position.xyz);\n"
-"  #if SHADER_MODEL > 2\n"
+"  #if __VERSION__ > 120\n"
 "          if (gl_LightSource[i].spotCutoff < 91.0) {  // Tube light\n"
 "              float beamlength = length(gl_LightSource[i].spotDirection);\n"
 "              vec3 beamDir = normalize(gl_LightSource[i].spotDirection);\n"
@@ -1904,14 +1904,6 @@ char* Default_fxaa_fragment_shader =
 "#extension GL_EXT_gpu_shader4 : enable\n"
 "#define FXAA_EARLY_EXIT 1\n"
 "#define FXAA_DISCARD 1\n"
-"#if SHADER_MODEL == 2\n"
-"	#define FXAA_GLSL_120 1\n"
-"	#define FXAA_GLSL_130 0\n"
-"#endif\n"
-"#if SHADER_MODEL > 2\n"
-"	#define FXAA_GLSL_120 0\n"
-"	#define FXAA_GLSL_130 1\n"
-"#endif\n"
 "#ifndef FXAA_FAST_PIXEL_OFFSET\n"
 "	#ifdef GL_EXT_gpu_shader4\n"
 "		#define FXAA_FAST_PIXEL_OFFSET 1\n"

code/graphics/2d.cpp

@@ -1740,7 +1740,7 @@ void poly_list::allocate(int _verts)
 			tsb = (tsb_t*)vm_malloc(sizeof(tsb_t) * _verts);
 		}
 
-		if ( Use_GLSL >= 3 ) {
+		if ( GLSL_version >= 130 ) {
 			submodels = (int*)vm_malloc(sizeof(int) * _verts);
 		}
 
@@ -1922,7 +1922,7 @@ void poly_list::make_index_buffer(SCP_vector<int> &vertex_list)
 			buffer_list_internal.tsb[z] = tsb[j];
 		}
 
-		if ( Use_GLSL >= 3 ) {
+		if ( GLSL_version >= 130 ) {
 			buffer_list_internal.submodels[z] = submodels[j];
 		}
 
@@ -1952,7 +1952,7 @@ poly_list& poly_list::operator = (poly_list &other_list)
 		memcpy(tsb, other_list.tsb, sizeof(tsb_t) * other_list.n_verts);
 	}
 
-	if ( Use_GLSL >= 3 ) {
+	if ( GLSL_version >= 130 ) {
 		memcpy(submodels, other_list.submodels, sizeof(int) * other_list.n_verts);
 	}
 
@@ -2147,7 +2147,7 @@ uint gr_determine_model_shader_flags(
 ) {
 	uint shader_flags = 0;
 
-	if ( Use_GLSL > 1 ) {
+	if ( GLSL_version >= 120 ) {
 		shader_flags |= SDR_FLAG_MODEL_CLIP;
 	}
 

code/graphics/grbatch.cpp

@@ -728,12 +728,12 @@ int batch_add_bitmap(int texture, int tmap_flags, vertex *pnt, int orient, float
 		return 1;
 	}
 
-	if ( tmap_flags & TMAP_FLAG_SOFT_QUAD && ( !Cmdline_softparticles || Use_GLSL <= 2 ) ) {
+	if ( tmap_flags & TMAP_FLAG_SOFT_QUAD && ( !Cmdline_softparticles || GLSL_version <= 120 ) ) {
 		// don't render this as a soft particle if we don't support soft particles
 		tmap_flags &= ~(TMAP_FLAG_SOFT_QUAD);
 	}
 
-	if ( Use_GLSL > 2 && Cmdline_softparticles && !Cmdline_no_geo_sdr_effects && Is_Extension_Enabled(OGL_EXT_GEOMETRY_SHADER4) && (tmap_flags & TMAP_FLAG_VERTEX_GEN) ) {
+	if ( GLSL_version > 120 && Cmdline_softparticles && !Cmdline_no_geo_sdr_effects && Is_Extension_Enabled(OGL_EXT_GEOMETRY_SHADER4) && (tmap_flags & TMAP_FLAG_VERTEX_GEN) ) {
 		geometry_batch_add_bitmap(texture, tmap_flags, pnt, orient, rad, alpha, depth);
 		return 0;
 	} else if ( tmap_flags & TMAP_FLAG_VERTEX_GEN ) {
@@ -797,7 +797,7 @@ int batch_add_bitmap_rotated(int texture, int tmap_flags, vertex *pnt, float ang
 		return 1;
 	}
 
-	if ( tmap_flags & TMAP_FLAG_SOFT_QUAD && ( !Cmdline_softparticles || Use_GLSL <= 2 ) ) {
+	if ( tmap_flags & TMAP_FLAG_SOFT_QUAD && ( !Cmdline_softparticles || GLSL_version <= 120 ) ) {
 		// don't render this as a soft particle if we don't support soft particles
 		tmap_flags &= ~(TMAP_FLAG_SOFT_QUAD);
 	}
@@ -1179,7 +1179,7 @@ int distortion_add_bitmap_rotated(int texture, int tmap_flags, vertex *pnt, floa
 		return 1;
 	}
 
-	if ( Use_GLSL < 2 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
+	if ( GLSL_version < 120 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
 		// don't render distortions if we can't support them.
 		return 0;
 	}
@@ -1214,7 +1214,7 @@ int distortion_add_beam(int texture, int tmap_flags, vec3d *start, vec3d *end, f
 		return 1;
 	}
 
-	if ( Use_GLSL < 2 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
+	if ( GLSL_version < 120 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
 		// don't render distortions if we can't support them.
 		return 0;
 	}

code/graphics/gropengl.cpp

@@ -51,7 +51,11 @@ typedef int ( * PFNGLXSWAPINTERVALSGIPROC) (int interval);
 // minimum GL version we can reliably support is 1.2
 static const int MIN_REQUIRED_GL_VERSION = 12;
 
+// minimum GLSL version we can reliably support is 110
+static const int MIN_REQUIRED_GLSL_VERSION = 110;
+
 int GL_version = 0;
+int GLSL_version = 0;
 
 bool GL_initted = 0;
 
@@ -71,7 +75,6 @@ static ushort *GL_original_gamma_ramp = NULL;
 
 int Use_VBOs = 0;
 int Use_PBOs = 0;
-int Use_GLSL = 0;
 
 static int GL_dump_frames = 0;
 static ubyte *GL_dump_buffer = NULL;
@@ -2011,7 +2014,7 @@ bool gr_opengl_init()
 	GLint max_texture_units = GL_supported_texture_units;
 	GLint max_texture_coords = GL_supported_texture_units;
 
-	if (Use_GLSL) {
+	if (is_minimum_GLSL_version()) {
 		glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &max_texture_units);
 	}
 
@@ -2091,7 +2094,7 @@ bool gr_opengl_init()
 	mprintf(( "  Post-processing enabled: %s\n", (Cmdline_postprocess) ? "YES" : "NO"));
 	mprintf(( "  Using %s texture filter.\n", (GL_mipmap_filter) ? NOX("trilinear") : NOX("bilinear") ));
 
-	if (Use_GLSL) {
+	if (is_minimum_GLSL_version()) {
 		mprintf(( "  OpenGL Shader Version: %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION) ));
 	}
 
@@ -2166,3 +2169,15 @@ DCF(ogl_anisotropy, "toggles anisotropic filtering")
 		//	opengl_set_anisotropy( (float)Dc_arg_float );
 	}
 }
+
+/**
+ * Helper function to enquire whether minimum GLSL version present.
+ *
+ * Compares global variable set by glGetString(GL_SHADING_LANGUAGE_VERSION)
+ * against compile time MIN_REQUIRED_GLSL_VERSION.
+ *
+ * @return true if GLSL support present is above the minimum version.
+ */
+bool is_minimum_GLSL_version() {
+	return GLSL_version >= MIN_REQUIRED_GLSL_VERSION ? true : false;
+}

code/graphics/gropengl.h

@@ -655,6 +655,7 @@ const ubyte GL_zero_3ub[3] = { 0, 0, 0 };
 bool gr_opengl_init();
 void gr_opengl_cleanup(int minimize=1);
 int opengl_check_for_errors(char *err_at = NULL);
+bool is_minimum_GLSL_version();
 
 #ifndef NDEBUG
 #define GL_CHECK_FOR_ERRORS(s)	opengl_check_for_errors((s))
@@ -663,9 +664,9 @@ int opengl_check_for_errors(char *err_at = NULL);
 #endif
 
 extern int GL_version;
+extern int GLSL_version;
 
 extern int Use_VBOs;
 extern int Use_PBOs;
-extern int Use_GLSL;
 
 #endif

code/graphics/gropengldraw.cpp

@@ -2546,7 +2546,7 @@ void opengl_setup_scene_textures()
 {
 	Scene_texture_initialized = 0;
 
-	if ( !Use_GLSL || Cmdline_no_fbo || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
+	if ( !is_minimum_GLSL_version() || Cmdline_no_fbo || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) ) {
 		Cmdline_postprocess = 0;
 		Cmdline_softparticles = 0;
 		Cmdline_fb_explosions = 0;
@@ -3067,7 +3067,7 @@ void opengl_clear_deferred_buffers()
 
 void gr_opengl_deferred_lighting_begin()
 {
-	if (Use_GLSL < 2 || Cmdline_no_deferred_lighting)
+	if (GLSL_version < 120 || Cmdline_no_deferred_lighting)
 		return;
 
 	Deferred_lighting = true;
@@ -3093,7 +3093,7 @@ extern float static_tube_factor;
 
 void gr_opengl_deferred_lighting_finish()
 {
-	if ( Use_GLSL < 2 || Cmdline_no_deferred_lighting ) {
+	if ( GLSL_version < 120 || Cmdline_no_deferred_lighting ) {
 		return;
 	}
 

code/graphics/gropenglextension.cpp

@@ -444,41 +444,30 @@ void opengl_extensions_init()
 		sscanf(glsl_ver, "%d.%d", &major, &minor);
 		ver = (major * 100) + minor;
 
-		// SM 4.0 compatible or better
-		if (ver >= 400) {
-			Use_GLSL = 4;
-		}
-		// SM 3.0 compatible
-		else if ( ver >= 130 ) {
-			Use_GLSL = 3;
-		}
-		// SM 2.0 compatible
-		else if (ver >= 120) {
-			Use_GLSL = 2;
-		}
-		// we require GLSL 1.20 or higher
-		else if (ver < 110) {
-			Use_GLSL = 0;
+		GLSL_version = ver;
+
+		// we require a minimum GLSL version
+		if (!is_minimum_GLSL_version()) {
 			mprintf(("  OpenGL Shading Language version %s is not sufficient to use GLSL mode in FSO. Defaulting to fixed-function renderer.\n", glGetString(GL_SHADING_LANGUAGE_VERSION) ));
 		}
 	}
 
 	// can't have this stuff without GLSL support
-	if ( !Use_GLSL ) {
+	if ( !is_minimum_GLSL_version() ) {
 		Cmdline_normal = 0;
 		Cmdline_height = 0;
 		Cmdline_postprocess = 0;
 		Cmdline_shadow_quality = 0;
 		Cmdline_no_deferred_lighting = 1;
 	}
 
-	if ( Use_GLSL < 2 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) || !Is_Extension_Enabled(OGL_ARB_FLOATING_POINT_TEXTURES) ) {
+	if ( GLSL_version < 120 || !Is_Extension_Enabled(OGL_EXT_FRAMEBUFFER_OBJECT) || !Is_Extension_Enabled(OGL_ARB_FLOATING_POINT_TEXTURES) ) {
         mprintf(("  No hardware support for deferred lighting. Deferred lighting will be disabled. \n"));
 		Cmdline_no_deferred_lighting = 1;
 		Cmdline_no_batching = true;
 	}
 
-	if (Use_GLSL) {
+	if (is_minimum_GLSL_version()) {
 		GLint max_texture_units;
 		glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS_ARB, &max_texture_units);
 
@@ -493,7 +482,7 @@ void opengl_extensions_init()
 			Cmdline_height = 0;
 		} else if (max_texture_units < 4) {
 			mprintf(( "Not enough texture units found for GLSL support. We need at least 4, we found %d.\n", max_texture_units ));
-			Use_GLSL = 0;
+			GLSL_version = 0;
 		}
 	}
 }