medfall

commit cb20f91d3b7b9ad57f2829869df738dd03327818
parent ad69870125f9d260a4d667396d469b8662c089ad
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Mon, 26 Mar 2018 23:48:33 +0300

stb_truetype font supersampling

Diffstat:
main.cc
 | 
2
+-
text_renderer.cc
 | 
66
++++++++++++++++++++++++++++++++++++------------------------------
text_renderer.h
 | 
7
+++++--

3 files changed, 42 insertions(+), 33 deletions(-)
diff --git a/main.cc b/main.cc
@@ -45,7 +45,7 @@ int main( int argc, char ** argv ) {
 	GLFWwindow * window = gl_init( WINDOW_GAME );
 	renderer_init();
 	shaders_init();
-	text_renderer_init();
+	text_renderer_init( &mem.persistent_arena );
 	workqueue_init( &state.background_tasks, &mem.persistent_arena, 4 );
 	game_init( &state, &mem );
 
diff --git a/text_renderer.cc b/text_renderer.cc
@@ -1,4 +1,5 @@
 #include "intrinsics.h"
+#include "memory_arena.h"
 #include "immediate.h"
 #include "gl.h"
 #include "renderer.h"
@@ -11,18 +12,22 @@
 struct FontSize {
 	float pixel_size;
 	float ascent;
-	Texture atlas;
-	stbtt_bakedchar baked_chars[ 256 ];
+	stbtt_packedchar baked_chars[ 256 ];
 };
 
-static stbtt_fontinfo font_info;
+constexpr u32 atlas_width = 1024;
+constexpr u32 atlas_height = 512;
+static Texture atlas;
 
 static const float pixel_sizes[] = { 16.0f, 32.0f, 48.0f };
 static FontSize sizes[ ARRAY_COUNT( pixel_sizes ) ];
 
-void text_renderer_init() {
-	const u8 * ttf = LiberationSans_Regular_ttf;
+void text_renderer_init( MemoryArena * arena ) {
+	MEMARENA_SCOPED_CHECKPOINT( arena );
 
+	u8 * ttf = ( u8 * ) LiberationSans_Regular_ttf;
+
+	stbtt_fontinfo font_info;
 	int offset = stbtt_GetFontOffsetForIndex( ttf, 0 );
 	{
 		int ok = stbtt_InitFont( &font_info, ttf, offset );
@@ -32,28 +37,35 @@ void text_renderer_init() {
 	int ascent;
 	stbtt_GetFontVMetrics( &font_info, &ascent, NULL, NULL );
 
-	for( size_t i = 0; i < ARRAY_COUNT( sizes ); i++ ) {
-		const u32 width = 512;
-		const u32 height = 256;
-		u8 texture[ width * height ];
-		float pixel_size = pixel_sizes[ i ];
+	u8 * texture = memarena_push_many( arena, u8, atlas_width * atlas_height );
+	stbtt_pack_context pack_context;
+	int begin_ok = stbtt_PackBegin( &pack_context, texture, atlas_width, atlas_height, 0, 1, NULL );
+	if( begin_ok == 0 )
+		FATAL( "stbtt_PackBegin" );
 
-		int ok = stbtt_BakeFontBitmap( ttf, offset, pixel_size, texture, width, height, ' ', 127 - ' ', sizes[ i ].baked_chars );
+	for( size_t i = 0; i < ARRAY_COUNT( sizes ); i++ ) {
+		stbtt_PackSetOversampling( &pack_context, 2, 2 );
+		int ok = stbtt_PackFontRange( &pack_context, ttf, 0, pixel_sizes[ i ], ' ', 127 - ' ', sizes[ i ].baked_chars );
 		ASSERT( ok != 0 );
 
-		float scale = stbtt_ScaleForPixelHeight( &font_info, pixel_size );
-
-		TextureConfig texture_config;
-		texture_config.width = width;
-		texture_config.height = height;
-		texture_config.format = TEXFMT_R_U8;
-		texture_config.data = texture;
-		texture_config.data_size = sizeof( texture );
-
-		sizes[ i ].pixel_size = pixel_size;
+		float scale = stbtt_ScaleForPixelHeight( &font_info, pixel_sizes[ i ] );
+		sizes[ i ].pixel_size = pixel_sizes[ i ];
 		sizes[ i ].ascent = ascent * scale;
-		sizes[ i ].atlas = renderer_new_texture( texture_config );
 	}
+
+	stbtt_PackEnd( &pack_context );
+
+	TextureConfig texture_config;
+	texture_config.width = atlas_width;
+	texture_config.height = atlas_height;
+	texture_config.format = TEXFMT_R_U8;
+	texture_config.data = texture;
+	texture_config.data_size = sizeof( texture );
+	atlas = renderer_new_texture( texture_config );
+}
+
+void text_renderer_term() {
+	renderer_delete_texture( atlas );
 }
 
 void draw_text( const char * str, int x, int y, float pixel_size ) {
@@ -77,7 +89,7 @@ void draw_text( const char * str, int x, int y, float pixel_size ) {
 
 	while( *str != '\0' ) {
 		stbtt_aligned_quad q;
-		stbtt_GetBakedQuad( sizes[ size_idx ].baked_chars, 512, 256, *str - ' ', &fx, &fy, &q, 1 );
+		stbtt_GetPackedQuad( sizes[ size_idx ].baked_chars, atlas_width, atlas_height, *str - ' ', &fx, &fy, &q, 0 );
 
 		ImmediateVertex tl = {
 			v3( left + scale * ( q.x0 - left ), top + scale * ( q.y0 - y ), 0 ),
@@ -112,7 +124,7 @@ void draw_text( const char * str, int x, int y, float pixel_size ) {
 
 	RenderState render_state;
 	render_state.shader = get_shader( SHADER_TEXT );
-	render_state.textures[ 0 ] = sizes[ size_idx ].atlas;
+	render_state.textures[ 0 ] = atlas;
 	render_state.uniforms[ UNIFORMS_WINDOW ] = renderer_uniforms( get_window_size() );
 	render_state.depth_func = DEPTHFUNC_DISABLED;
 	render_state.enable_alpha_blending = true;
@@ -120,9 +132,3 @@ void draw_text( const char * str, int x, int y, float pixel_size ) {
 
 	immediate_render( render_state );
 }
-
-void text_renderer_term() {
-	for( size_t i = 0; i < ARRAY_COUNT( sizes ); i++ ) {
-		renderer_delete_texture( sizes[ i ].atlas );
-	}
-}
diff --git a/text_renderer.h b/text_renderer.h
@@ -1,5 +1,8 @@
 #pragma once
 
-void text_renderer_init();
-void draw_text( const char * str, int x, int y, float pixel_size );
+#include "memory_arena.h"
+
+void text_renderer_init( MemoryArena * arena );
 void text_renderer_term();
+
+void draw_text( const char * str, int x, int y, float pixel_size );