Comments & formatting

quakespasm/Quake/compile_vertexshader.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+# cgc from https://developer.nvidia.com/cg-toolkit
+
 rm -f r_alias_vertexshader.h
 rm -f r_alias_vertexshader.vp
 

quakespasm/Quake/gl_mesh.c

@@ -347,7 +347,7 @@ void GL_MakeAliasModelDisplayLists (qmodel_t *m, aliashdr_t *hdr)
 	for (i=0 ; i<paliashdr->numposes ; i++)
 		for (j=0 ; j<numorder ; j++)
 			*verts++ = poseverts[i][vertexorder[j]];
-			
+
 	// ericw
 	GL_MakeAliasModelDisplayLists_VBO ();
 }
@@ -359,6 +359,9 @@ unsigned int r_meshvertexbuffer = 0;
 ================
 GL_MakeAliasModelDisplayLists_VBO
 
+Saves data needed to build the VBO for this model on the hunk. Afterwards this
+is copied to Mod_Extradata.
+
 Original code by MH from RMQEngine
 ================
 */
@@ -372,14 +375,14 @@ void GL_MakeAliasModelDisplayLists_VBO (void)
 
 	if (!GLAlias_SupportsShaders())
 		return;
-	
+
 	// first, copy the verts onto the hunk
 	verts = (trivertx_t *) Hunk_Alloc (paliashdr->numposes * paliashdr->numverts * sizeof(trivertx_t));
 	paliashdr->vertexes = (byte *)verts - (byte *)paliashdr;
 	for (i=0 ; i<paliashdr->numposes ; i++)
 		for (j=0 ; j<paliashdr->numverts ; j++)
 			verts[i*paliashdr->numverts + j] = poseverts[i][j];
-	
+
 	// there can never be more than this number of verts and we just put them all on the hunk
 	maxverts_vbo = pheader->numtris * 3;
 	desc = (aliasmesh_t *) Hunk_Alloc (sizeof (aliasmesh_t) * maxverts_vbo);
@@ -445,6 +448,9 @@ GLuint r_meshindexesvbo = 0;
 ================
 GLMesh_LoadVertexBuffers
 
+Loop over all precached alias models, and upload them into one big VBO plus
+an GL_ELEMENT_ARRAY_BUFFER for the vertex indices.
+
 Original code by MH from RMQEngine
 ================
 */
@@ -454,10 +460,10 @@ void GLMesh_LoadVertexBuffers (void)
 	qmodel_t *m;
 	int totalindexes = 0;
 	int totalvbosize = 0;
-	
+
 	if (!GLAlias_SupportsShaders())
 		return;
-	
+
 	// pass 1 - count the sizes we need
 	for (j = 1; j < MAX_MODELS; j++)
 	{
@@ -503,7 +509,7 @@ void GLMesh_LoadVertexBuffers (void)
 		aliasmesh_t *desc;
 		meshst_t *st;
 		float hscale, vscale;
-		
+
 		if (!(m = cl.model_precache[j])) break;
 		if (m->type != mod_alias) continue;
 
@@ -529,7 +535,7 @@ void GLMesh_LoadVertexBuffers (void)
 			for (v = 0; v < hdr->numverts_vbo; v++)
 			{
 				trivertx_t trivert = tv[desc[v].vertindex];
-				
+
 				xyz[v].xyz[0] = trivert.v[0];
 				xyz[v].xyz[1] = trivert.v[1];
 				xyz[v].xyz[2] = trivert.v[2];

quakespasm/Quake/gl_rmisc.c

@@ -325,29 +325,35 @@ void D_FlushCaches (void)
 static GLuint gl_arb_programs[16];
 static int gl_num_arb_programs = 0;
 
-// from RMQEngine
+/*
+====================
+GL_CreateProgram
+
+Compiles an ARB vertex program. from RMQEngine
+====================
+*/
 GLuint GL_CreateProgram (const GLchar *source)
 {
 	GLuint progid;
 	GLint errPos;
 	const GLubyte *errString;
 	GLenum errGLErr;
-		
+
 	GL_GenProgramsARBFunc (1, &progid);
 	GL_BindProgramARBFunc (GL_VERTEX_PROGRAM_ARB, progid);
-	
+
 	errGLErr = glGetError ();
 	GL_ProgramStringARBFunc (GL_VERTEX_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB, strlen (source), source);
 	errGLErr = glGetError ();
-	
+
 	// Find the error position
 	glGetIntegerv (GL_PROGRAM_ERROR_POSITION_ARB, &errPos);
 	errString = glGetString (GL_PROGRAM_ERROR_STRING_ARB);
-	
-	if (errGLErr != GL_NO_ERROR) Con_Printf ("Generic OpenGL Error\n");
-	if (errPos != -1) Con_Printf ("Program error at position: %d\n", errPos);
-	if (errString && errString[0]) Con_Printf ("Program error: %s\n", errString);
-	
+
+	if (errGLErr != GL_NO_ERROR) Con_Warning ("GL_CreateProgram: Generic OpenGL Error\n");
+	if (errPos != -1) Con_Warning ("GL_CreateProgram: Program error at position: %d\n", errPos);
+	if (errString && errString[0]) Con_Warning ("GL_CreateProgram: Program error: %s\n", errString);
+
 	if ((errPos != -1) || (errString && errString[0]) || (errGLErr != GL_NO_ERROR))
 	{
 		Con_Printf ("Program:\n%s\n", source);
@@ -362,12 +368,19 @@ GLuint GL_CreateProgram (const GLchar *source)
 
 		gl_arb_programs[gl_num_arb_programs] = progid;
 		gl_num_arb_programs++;
-		
+
 		GL_BindProgramARBFunc (GL_VERTEX_PROGRAM_ARB, 0);
 		return progid;
 	}
 }
 
+/*
+====================
+R_DeleteShaders
+
+Deletes any ARB programs that have been created.
+====================
+*/
 void R_DeleteShaders (void)
 {
 	GL_DeleteProgramsARBFunc (sizeof(gl_arb_programs)/sizeof(GLuint), gl_arb_programs);

quakespasm/Quake/gl_vidsdl.c

@@ -1018,7 +1018,7 @@ static void GL_CheckExtensions (void)
 	{
 		Con_Warning ("texture_non_power_of_two not supported\n");
 	}
-	
+
 	// GL_ARB_vertex_program
 	//
 	if (COM_CheckParm("-novertexprogram"))
@@ -1026,7 +1026,7 @@ static void GL_CheckExtensions (void)
 	else
 	{
 		qboolean ok = true;
-		
+
 		if (!(GL_BindProgramARBFunc = (PFNGLBINDPROGRAMARBPROC) SDL_GL_GetProcAddress ("glBindProgramARB"))) ok = false;
 		if (!(GL_DeleteProgramsARBFunc = (PFNGLDELETEPROGRAMSARBPROC) SDL_GL_GetProcAddress ("glDeleteProgramsARB"))) ok = false;
 		if (!(GL_GenProgramsARBFunc = (PFNGLGENPROGRAMSARBPROC) SDL_GL_GetProcAddress ("glGenProgramsARB"))) ok = false;
@@ -1049,7 +1049,7 @@ static void GL_CheckExtensions (void)
 		if (!(GL_VertexAttribPointerARBFunc = (PFNGLVERTEXATTRIBPOINTERARBPROC) SDL_GL_GetProcAddress ("glVertexAttribPointerARB"))) ok = false;
 		if (!(GL_EnableVertexAttribArrayARBFunc = (PFNGLENABLEVERTEXATTRIBARRAYARBPROC) SDL_GL_GetProcAddress ("glEnableVertexAttribArrayARB"))) ok = false;
 		if (!(GL_DisableVertexAttribArrayARBFunc = (PFNGLDISABLEVERTEXATTRIBARRAYARBPROC) SDL_GL_GetProcAddress ("glDisableVertexAttribArrayARB"))) ok = false;
-		
+
 		if (ok)
 		{
 			Con_Printf("FOUND: GL_ARB_vertex_program\n");
@@ -1063,8 +1063,8 @@ static void GL_CheckExtensions (void)
 }
 
 /*
- ===============
- GL_SetupState -- johnfitz
+===============
+GL_SetupState -- johnfitz
 
 does all the stuff from GL_Init that needs to be done every time a new GL render context is created
 ===============
@@ -1121,7 +1121,7 @@ static void GL_Init (void)
 		Cbuf_AddText ("gl_clear 1");
 	}
 	//johnfitz
-	
+
 	R_DeleteShaders ();
 	GLAlias_CreateShaders ();
 }

quakespasm/Quake/r_alias.c

@@ -67,7 +67,7 @@ typedef struct {
 } lerpdata_t;
 //johnfitz
 
-static GLuint shader;
+static GLuint r_alias_vertex_program;
 
 extern GLuint r_meshvbo;
 extern GLuint r_meshindexesvbo;
@@ -88,9 +88,16 @@ void *GLARB_GetNormalOffset (aliashdr_t *hdr, int pose)
 
 qboolean GLAlias_SupportsShaders (void)
 {
-       return gl_arb_vp_able && gl_vbo_able && gl_max_texture_units >= 3;
+	return gl_arb_vp_able && gl_vbo_able && gl_max_texture_units >= 3;
 }
 
+/*
+=============
+GLAlias_CreateShaders -- ericw
+
+Creates the alias model vertex shader
+=============
+*/
 void GLAlias_CreateShaders (void)
 {
 		const GLchar *source = 
@@ -99,8 +106,8 @@ void GLAlias_CreateShaders (void)
 
 		if (!GLAlias_SupportsShaders())
 			return;
-	
-		shader = GL_CreateProgram(source);
+
+		r_alias_vertex_program = GL_CreateProgram(source);
 }
 
 /*
@@ -114,6 +121,17 @@ void GL_DrawAliasFrame_ARB (aliashdr_t *paliashdr, lerpdata_t lerpdata)
 {
 	float	blend;
 
+// program local indices - copied from vpalias.h
+	const GLuint blendLoc = 9;
+	const GLuint shadevectorLoc = 10;
+	const GLuint lightColorLoc = 11;
+	
+// vertex attribute indices - copied from vpalias.h
+	const GLint pose1VertexAttrIndex = 0;
+	const GLint pose1NormalAttrIndex = 1;
+	const GLint pose2VertexAttrIndex = 2;
+	const GLint pose2NormalAttrIndex = 3;
+
 	if (lerpdata.pose1 != lerpdata.pose2)
 	{
 		blend = lerpdata.blend;
@@ -122,62 +140,45 @@ void GL_DrawAliasFrame_ARB (aliashdr_t *paliashdr, lerpdata_t lerpdata)
 	{
 		blend = 0;
 	}
-	
-	// N.B.: Copied from vpalias.h
 
-	// program local indices
-	const GLuint blendLoc = 9;
-	const GLuint shadevectorLoc = 10;
-	const GLuint lightColorLoc = 11;
-	
-	// vertex attribute indices
-	const GLint pose1VertexAttrIndex = 0;
-	const GLint pose1NormalAttrIndex = 1;
-	const GLint pose2VertexAttrIndex = 2;
-	const GLint pose2NormalAttrIndex = 3;
-	
-	GL_BindProgramARBFunc (GL_VERTEX_PROGRAM_ARB, shader);
+	GL_BindProgramARBFunc (GL_VERTEX_PROGRAM_ARB, r_alias_vertex_program);
 	glEnable ( GL_VERTEX_PROGRAM_ARB );
 
-// ericw -- bind it and stuff
 	GL_BindBufferFunc (GL_ARRAY_BUFFER, r_meshvbo);
 	GL_BindBufferFunc (GL_ELEMENT_ARRAY_BUFFER, r_meshindexesvbo);
-	
+
 	GL_VertexAttribPointerARBFunc (pose1VertexAttrIndex, 4, GL_UNSIGNED_BYTE, GL_FALSE, sizeof (meshxyz_t), GLARB_GetXYZOffset (paliashdr, lerpdata.pose1));
 	GL_EnableVertexAttribArrayARBFunc (pose1VertexAttrIndex);
-		
+
 	GL_VertexAttribPointerARBFunc (pose2VertexAttrIndex, 4, GL_UNSIGNED_BYTE, GL_FALSE, sizeof (meshxyz_t), GLARB_GetXYZOffset (paliashdr, lerpdata.pose2));
 	GL_EnableVertexAttribArrayARBFunc (pose2VertexAttrIndex);
-	
+
 	GL_ClientActiveTextureFunc (GL_TEXTURE0_ARB);
 	glTexCoordPointer (2, GL_FLOAT, 0, (void *)(intptr_t)currententity->model->vbostofs);
 	glEnableClientState (GL_TEXTURE_COORD_ARRAY);
-	
+
 	GL_ClientActiveTextureFunc (GL_TEXTURE1_ARB);
 	glDisableClientState (GL_TEXTURE_COORD_ARRAY);
-	
+
 	GL_ClientActiveTextureFunc (GL_TEXTURE2_ARB);
 	glDisableClientState (GL_TEXTURE_COORD_ARRAY);
-	
+
 // GL_TRUE to normalize the signed bytes to [-1 .. 1]
 	GL_VertexAttribPointerARBFunc (pose1NormalAttrIndex, 3, GL_BYTE, GL_TRUE, sizeof (meshxyz_t), GLARB_GetNormalOffset (paliashdr, lerpdata.pose1));
 	GL_EnableVertexAttribArrayARBFunc (pose1NormalAttrIndex);
-		
+
 	GL_VertexAttribPointerARBFunc (pose2NormalAttrIndex, 3, GL_BYTE, GL_TRUE, sizeof (meshxyz_t), GLARB_GetNormalOffset (paliashdr, lerpdata.pose2));
 	GL_EnableVertexAttribArrayARBFunc (pose2NormalAttrIndex);
 
-	// set uniforms
-	
+// set uniforms
 	GL_ProgramLocalParameter4fARBFunc (GL_VERTEX_PROGRAM_ARB, blendLoc, blend, /* unused */ 0, 0, 0);
 	GL_ProgramLocalParameter4fARBFunc (GL_VERTEX_PROGRAM_ARB, shadevectorLoc, shadevector[0], shadevector[1], shadevector[2], /* unused */ 0);
 	GL_ProgramLocalParameter4fARBFunc (GL_VERTEX_PROGRAM_ARB, lightColorLoc, lightcolor[0], lightcolor[1], lightcolor[2], entalpha);
 
-	// draw
-
+// draw
 	glDrawElements (GL_TRIANGLES, paliashdr->numindexes, GL_UNSIGNED_SHORT, (void *)(intptr_t)currententity->model->vboindexofs);
 
-	// clean up
-
+// clean up
 	GL_DisableVertexAttribArrayARBFunc (pose1VertexAttrIndex);
 	GL_DisableVertexAttribArrayARBFunc (pose2VertexAttrIndex);
 
@@ -213,8 +214,9 @@ void GL_DrawAliasFrame (aliashdr_t *paliashdr, lerpdata_t lerpdata)
 	float	blend, iblend;
 	qboolean lerping;
 
-	// call fast path if possible
-	if (GLAlias_SupportsShaders() && !r_drawflat_cheatsafe && shading)
+// call fast path if possible. if the shader compliation failed for some reason,
+// r_alias_vertex_program will be 0.
+	if (GLAlias_SupportsShaders() && (r_alias_vertex_program != 0) && !r_drawflat_cheatsafe && shading)
 	{
 		GL_DrawAliasFrame_ARB (paliashdr, lerpdata);
 		return;
@@ -517,14 +519,16 @@ void R_SetupAliasLighting (entity_t	*e)
 
 	quantizedangle = ((int)(e->angles[1] * (SHADEDOT_QUANT / 360.0))) & (SHADEDOT_QUANT - 1);
 
+//ericw -- shadevector is passed to the shader to compute shadedots inside the
+//shader, see r_alias_vertexshader.glsl
 	radiansangle = (quantizedangle / 16.0) * 2.0 * 3.14159;
 	shadevector[0] = cos(-radiansangle);
 	shadevector[1] = sin(-radiansangle);
 	shadevector[2] = 1;
 	VectorNormalize(shadevector);
+//ericw --
 
 	shadedots = r_avertexnormal_dots[quantizedangle];
-
 	VectorScale (lightcolor, 1.0f / 200.0f, lightcolor);
 }
 

quakespasm/Quake/r_alias_vertexshader.glsl

@@ -1,5 +1,8 @@
 #version 110
 
+// Note: we’re not loading this directly but first compiling it to ARB_vertex_program
+// using compile_vertexshader.sh
+
 uniform float Blend;
 uniform vec3 ShadeVector;
 uniform vec4 LightColor;