X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=vg_build_utils_shader.h;fp=vg_build_utils_shader.h;h=77ce897e4f32297706aa692b2b9ff670b10742c5;hb=76f30a0f4aef82c10b4affbeab3f0271936ce7ca;hp=0000000000000000000000000000000000000000;hpb=4c48fe01a5d1983be89b7dce6f08e6b708cfbb05;p=vg.git

diff --git a/vg_build_utils_shader.h b/vg_build_utils_shader.h
new file mode 100644
index 0000000..77ce897
--- /dev/null
+++ b/vg_build_utils_shader.h
@@ -0,0 +1,248 @@
+#include "vg.h"
+
+#ifdef VG_GAME
+  #error !
+#endif
+
+#define STB_INCLUDE_IMPLEMENTATION
+#define STB_INCLUDE_LINE_GLSL
+#include "submodules/stb/stb_include.h"
+
+struct
+{
+   struct uniform
+   {
+      char name[32];
+      char type[20];
+      char uniform_code_id[128];
+
+      int array;
+   }
+   uniform_buffer[100];
+
+   int   uniform_count,
+         uniform_uid;
+   char  shader_dir[ 256 ];
+   char  current_shader_name[ 128 ];
+}
+static vg_shaderbuild;
+
+static void vg_shader_set_include_dir( char *dir )
+{
+   strcpy( vg_shaderbuild.shader_dir, dir );
+}
+
+static void parse_uniform_name( char *start, struct uniform *uf )
+{
+   uf->array = 0;
+   for( int i=0;; i++ )
+   {
+      if( start[i] == '\0' )
+         break;
+
+      if( start[i] == ';' )
+      {
+         start[i] = '\0';
+         strncpy( uf->name, start, sizeof(uf->name) );
+      }
+
+      if( start[i] == '[' )
+      {
+         start[i] = '\0';
+         strncpy( uf->name, start, sizeof(uf->name) );
+         uf->array = 1;
+      }
+      
+      if( start[i] == ' ' )
+      {
+         start[i] = '\0';
+         strncpy( uf->type, start, sizeof(uf->type) );
+         start = start+i+1;
+         i=0;
+      }
+   }
+
+   snprintf( uf->uniform_code_id, 64, "_uniform_%s_%s",
+             vg_shaderbuild.current_shader_name,
+             uf->name );
+}
+
+static int compile_subshader( FILE *header, char *name )
+{
+   char error[256];
+   char *full = stb_include_file( name, "", vg_shaderbuild.shader_dir, error );
+
+   if( !full )
+   {
+      fprintf( stderr, "stb_include_file error:\n%s\n", error );
+      return 0;
+   }
+   else
+   {
+      fprintf( header, "{\n"
+                       ".static_src = \n" );
+
+      char *cur = full, *start = full;
+      while( 1 )
+      {
+         char c = *cur;
+         if( c == '\n' || c == '\0' )
+         {
+            *cur = '\0';
+            fputs( "\"", header );
+            fputs( start, header );
+
+            if( !strncmp(start,"uniform",7) )
+            {
+               start += 8;
+               struct uniform *uf = 
+                  &vg_shaderbuild.uniform_buffer[ 
+                        vg_shaderbuild.uniform_count ++ ];
+
+               parse_uniform_name( start, uf );
+            }
+
+            if( c == '\0' )
+            {
+               fputs( "\"", header );
+               break;
+            }
+
+            fputs( "\\n\"\n", header );
+            start = cur+1;
+         }
+         cur ++;
+      }
+
+      fputs( "},", header );
+   }
+
+   free( full );
+   return 1;
+}
+
+int vg_build_shader( char *src_vert, /* path/to/vert.vs    */
+                     char *src_frag, /* path/to/frag.fs    */
+                     char *src_geo,  /* unused currently   */
+                     char *dst_h,    /* folder where .h go */
+                     char *name      /* shader name        */ )
+{
+   char path[260];
+   
+   strcpy( vg_shaderbuild.current_shader_name, name );
+
+   strcpy( path, dst_h );
+   strcat( path, "/" );
+   strcat( path, name );
+   strcat( path, ".h" );
+
+   printf( "Compiling shader called '%s'\n", name );
+
+   FILE *header = fopen( path, "w" );
+   if( !header )
+   {
+      fprintf(stderr, "Could not open '%s'\n", path );
+      return 0;
+   }
+   
+   fprintf( header, "#ifndef SHADER_%s_H\n"
+                    "#define SHADER_%s_H\n", name, name );
+   fprintf( header, "static void shader_%s_link(void);\n", name );
+   fprintf( header, "static void shader_%s_register(void);\n", name );
+   fprintf( header, "static struct vg_shader _shader_%s = {\n"
+                    "   .name = \"%s\",\n"
+                    "   .link = shader_%s_link,\n"
+                    "   .vs = \n", name, name, name );
+
+   vg_shaderbuild.uniform_count = 0;
+   if( !compile_subshader(header,src_vert) )
+   {
+      fclose( header );
+      return 0;
+   }
+
+   fprintf( header, "\n   .fs = \n" );
+   if( !compile_subshader(header,src_frag) )
+   {
+      fclose( header );
+      return 0;
+   }
+
+   fprintf( header, "\n};\n\n" );
+   
+   for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
+   {
+      struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
+      fprintf( header, "static GLuint %s;\n", uf->uniform_code_id );
+   }
+
+   struct type_info
+   {
+      const char *glsl_type,
+                 *args,
+                 *gl_call_pattern;
+   }
+   types[] =
+   {
+      { "float", "float f", "glUniform1f(%s,f);" },
+
+      { "vec2", "v2f v", "glUniform2fv(%s,1,v);" },
+      { "vec3", "v3f v", "glUniform3fv(%s,1,v);" },
+      { "vec4", "v4f v", "glUniform4fv(%s,1,v);" },
+
+      { "sampler2D", "int i", "glUniform1i(%s,i);" },
+      { "mat4x3", "m4x3f m", "glUniformMatrix4x3fv(%s,1,GL_FALSE,(float*)m);" },
+      { "mat3", "m3x3f m", "glUniformMatrix3fv(%s,1,GL_FALSE,(float*)m);" },
+      { "mat4", "m4x4f m", "glUniformMatrix4fv(%s,1,GL_FALSE,(float*)m);" },
+   };
+
+   for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
+   {
+      struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
+      if( uf->array ) continue;
+
+      for( int j=0; j<vg_list_size(types); j ++ )
+      {
+         struct type_info *inf = &types[j];
+
+         if( !strcmp( inf->glsl_type, uf->type ) )
+         {
+            fprintf( header, "static void shader_%s_%s(%s){\n", 
+                              name, uf->name, inf->args );
+            fprintf( header, "   " );
+            fprintf( header, inf->gl_call_pattern, uf->uniform_code_id );
+            fprintf( header, "\n}\n" );
+         }
+      }
+   }
+
+   fprintf( header,
+         "static void shader_%s_register(void){\n"
+         "   vg_shader_register( &_shader_%s );\n"
+         "}\n",
+            name,name );
+
+   fprintf( header,
+         "static void shader_%s_use(void){ glUseProgram(_shader_%s.id); }\n",
+            name, name );
+
+   fprintf( header,
+         "static void shader_%s_link(void){\n",
+            name );
+
+   for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
+   {
+      struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
+      fprintf( header, 
+         "   _uniform_%s_%s = "
+            "glGetUniformLocation( _shader_%s.id, \"%s\" );\n",
+         name, uf->name,
+         name, uf->name );
+   }
+
+   fprintf( header, "}\n" );
+   fprintf( header, "#endif /* SHADER_%s_H */\n", name );
+   fclose( header );
+
+   return 1;
+}