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

@@ -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
 ================
 */
@@ -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
 ================
 */

quakespasm/Quake/gl_rmisc.c

@@ -325,7 +325,13 @@ 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;
@@ -344,9 +350,9 @@ GLuint GL_CreateProgram (const GLchar *source)
 	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))
 	{
@@ -368,6 +374,13 @@ GLuint GL_CreateProgram (const GLchar *source)
 	}
 }
 
+/*
+====================
+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

@@ -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
 ===============

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 = 
@@ -100,7 +107,7 @@ 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;
@@ -123,23 +141,9 @@ 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);
 
@@ -166,18 +170,15 @@ void GL_DrawAliasFrame_ARB (aliashdr_t *paliashdr, lerpdata_t lerpdata)
 	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;