X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=vg%2Fvg_shader.h;fp=vg%2Fvg_shader.h;h=ff8a5f0dc143c6126167394579fc4cced7922499;hb=6836e834f8db725e08015a98401f2be97e5b9849;hp=0000000000000000000000000000000000000000;hpb=b5740880fe3ffe59546bb80173ad3a6e1312648e;p=vg.git

diff --git a/vg/vg_shader.h b/vg/vg_shader.h
new file mode 100644
index 0000000..ff8a5f0
--- /dev/null
+++ b/vg/vg_shader.h
@@ -0,0 +1,168 @@
+// Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
+
+const char *vg_shader_gl_ver = "#version 330 core\n";
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wreturn-type"
+static inline int static_str_index( const char *list[], int len, const char *str )
+{
+    for( int i = 0; i < len; i ++ )
+    {
+        if( !strcmp(list[i],str) )
+            return i;
+    }
+    
+    #ifndef VG_RELEASE
+    fprintf( stderr, "That was not a static string index!! (%s)\n", str );
+    abort();
+    #endif
+}
+#pragma GCC diagnostic pop
+
+#define SHADER_NAME( NAME ) (NAME##_static_shader.program)
+#define SHADER_USE( NAME ) glUseProgram( NAME##_static_shader.program )
+
+#define SHADER_UNIFORM( NAME, U ) NAME##_shader_uniforms[ STR_STATIC_INDEX( NAME##_shader_names, U ) ]
+#define SHADER_UNIFORM_NAME( NAME, UID ) NAME##_shader_names[ UID ]
+#define STR_STATIC_INDEX( LIST, STR ) static_str_index( LIST, vg_list_size(LIST), STR )
+
+#define UNIFORMS(...) __VA_ARGS__
+
+#define SHADER_DEFINE( NAME, VERT, FRAG, UNIFORMS ) 							\
+	const char * NAME##_shader_names[] = UNIFORMS;								\
+	GLint NAME##_shader_uniforms[ vg_list_size( NAME##_shader_names ) ];	\
+	struct vg_shader NAME##_static_shader = {										\
+		.src_vert = VERT, .src_frag = FRAG,											\
+		.sym = #NAME "_static.shader",												\
+		.uniform_names = NAME##_shader_names,										\
+		.uniforms = NAME##_shader_uniforms,											\
+		.uniform_count = vg_list_size( NAME##_shader_names ),					\
+	};
+
+#define SHADER_INIT( NAME ) arrpush( vg_shaders_active, &NAME##_static_shader )
+
+#define SHADER_STATUS_NONE 0x00
+#define SHADER_STATUS_COMPILED 0x1
+
+struct vg_shader
+{
+	GLuint program;
+
+	const char *src_vert;
+	const char *src_frag;
+	const char *src_geo;
+	const char *sym;
+	
+	const char **uniform_names;
+	GLint *uniforms;
+	u32 uniform_count;
+	u32 status;
+}
+** vg_shaders_active = NULL;
+
+static GLuint vg_shader_subshader( const char *src, GLint gliShaderType )
+{
+	GLint shader = glCreateShader( gliShaderType );
+	glShaderSource( shader, 2, (const char *[2]){ vg_shader_gl_ver, src }, NULL );
+	glCompileShader( shader );
+
+	int success;
+	char infoLog[512];
+	glGetShaderiv( shader, GL_COMPILE_STATUS, &success );
+
+	if( !success )
+	{
+		glGetShaderInfoLog( shader, 512, NULL, infoLog );
+		vg_error( "Error info:\n%s\n", infoLog );
+		return 0;
+	}
+
+	return shader;
+}
+
+static int vg_shader_compile( struct vg_shader *shader )
+{
+	vg_info( "Compile shader '%s'\n", shader->sym );
+	
+	GLuint vert, frag, geo = 0;
+	
+	vert = vg_shader_subshader( shader->src_vert, GL_VERTEX_SHADER );
+	frag = vg_shader_subshader( shader->src_frag, GL_FRAGMENT_SHADER );
+	
+	if( !vert || !frag )
+		return 0;
+	
+	if( shader->src_geo )
+	{
+		geo = vg_shader_subshader( shader->src_geo, GL_GEOMETRY_SHADER );
+		
+		if( !geo )
+			return 0;
+	}
+	
+	shader->program = glCreateProgram();
+	if( geo )
+		glAttachShader( shader->program, geo );
+		
+	glAttachShader( shader->program, vert );
+	glAttachShader( shader->program, frag );
+	glLinkProgram( shader->program );
+	
+	glDeleteShader( vert );
+	glDeleteShader( frag );
+	
+	if( geo )
+		glDeleteShader( geo );
+		
+	// Check for link errors
+	char infoLog[ 512 ];
+	int success_link = 1;
+	
+	glGetProgramiv( shader->program, GL_LINK_STATUS, &success_link );
+	if( !success_link )
+	{
+		glGetProgramInfoLog( shader->program, 512, NULL, infoLog );
+		vg_error( "Link failed: %s\n", infoLog );
+		glDeleteProgram( shader->program );
+		
+		return 0;
+	}
+	
+	// Complete linkeage
+	for( int i = 0; i < shader->uniform_count; i ++ )
+		shader->uniforms[ i ] = glGetUniformLocation( shader->program, shader->uniform_names[i] );
+
+	shader->status |= SHADER_STATUS_COMPILED;
+	return 1;
+}
+
+static void vg_shaders_free(void)
+{
+	for( int i = 0; i < arrlen( vg_shaders_active ); i ++ )
+	{
+		struct vg_shader *shader = vg_shaders_active[i];
+		
+		if( shader->status & SHADER_STATUS_COMPILED )
+			glDeleteProgram( shader->program );
+	}
+	
+	arrfree( vg_shaders_active );
+}
+
+static int vg_shaders_compile(void)
+{
+	vg_info( "Compiling shaders\n" );
+
+	for( int i = 0; i < arrlen( vg_shaders_active ); i ++ )
+	{
+		struct vg_shader *shader = vg_shaders_active[i];
+		if( !vg_shader_compile( shader ) )
+		{
+			vg_shaders_free();
+			return 0;
+		}
+	}
+	
+	vg_register_exit( &vg_shaders_free, "vg_shaders_free" );
+	return 1;
+}