From 67d0a44f61c582d4a9886f91d86512253440b32b Mon Sep 17 00:00:00 2001
From: hgn <hgodden00@gmail.com>
Date: Thu, 14 Dec 2023 03:35:36 +0000
Subject: [PATCH] frosting ui style

---
 vg.h       |  6 ++--
 vg_imgui.h | 87 +++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/vg.h b/vg.h
index 04578f7..e62eb24 100644
--- a/vg.h
+++ b/vg.h
@@ -291,12 +291,12 @@ void async_internal_complete( void *payload, u32 size )
    SDL_AtomicUnlock( &vg.sl_status );
 }
 
-static void _vg_load_full( void *data )
-{
+static void _vg_load_full( void *data ){
    vg_preload();
+   vg_tex2d_replace_with_error( &vg.tex_missing );
+   vg_ui.tex_bg = vg.tex_missing;
 
    /* internal */
-   vg_tex2d_replace_with_error( &vg.tex_missing );
    vg_loader_step( vg_input_init, vg_input_free );
    vg_loader_step( vg_lines_init, NULL );
 #ifndef VG_NO_AUDIO
diff --git a/vg_imgui.h b/vg_imgui.h
index 750ebfb..c6553e6 100644
--- a/vg_imgui.h
+++ b/vg_imgui.h
@@ -200,7 +200,8 @@ struct{
 	}
    modal;
 	
-	GLuint tex_glyphs, vao, vbo, ebo;
+	GLuint tex_glyphs, vao, vbo, ebo, tex_bg;
+   v2f bg_inverse_ratio;
 
 	ui_px mouse[2], mouse_click[2];
    u32 mouse_state[2];
@@ -209,6 +210,7 @@ struct{
 
    ui_rect click_fader, click_fader_end;
    float click_fade_opacity;
+   f32 frosting;
 
    ui_scheme scheme;
    const ui_font *font;
@@ -222,7 +224,6 @@ struct{
    cursor;
 
    SDL_Cursor *cursor_map[ k_ui_cursor_max ];
-
    v4f colour;
 } 
 static vg_ui = {
@@ -263,59 +264,76 @@ static vg_ui = {
       [ k_ui_gray   + k_ui_brighter ] = UI_RGB( 0xa89984 ),
    },
    .font = &vg_ui_font_small,
-   .colour = {1.0f,1.0f,1.0f,1.0f}
+   .colour = {1.0f,1.0f,1.0f,1.0f},
+   .bg_inverse_ratio = {1,1}
 };
 
-static struct vg_shader _shader_ui =
-{
-   .name = "[vg] ui",
+static struct vg_shader _shader_ui ={
+   .name = "[vg] ui - transparent",
    .link = NULL,
-   .vs = 
-   {
+   .vs = {
       .orig_file = NULL,
       .static_src = 
 	"layout (location=0) in vec2 a_co;"
 	"layout (location=1) in vec2 a_uv;"
 	"layout (location=2) in vec4 a_colour;"
 	"uniform mat3 uPv;"
+   "uniform vec2 uBGInverseRatio;"
 	""
-	"out vec2 aTexCoords;"
+	"out vec4 aTexCoords;"
 	"out vec4 aColour;"
-	"out vec2 aWsp;"
 	""
-	"void main()"
-	"{"
-		"gl_Position = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
-		"aTexCoords = a_uv * 0.00390625;" /* TODO: Uniform */
+	"void main(){"
+      "vec4 proj_pos = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
+		"gl_Position = proj_pos;"
+		"aTexCoords = vec4( a_uv * 0.00390625, "
+                        " (proj_pos.xy*0.5+0.5) * uBGInverseRatio );"
 		"aColour = a_colour;"
-		
-		"aWsp = a_co;"
 	"}",
    },
-   .fs = 
-   {
+   .fs = {
       .orig_file = NULL,
       .static_src = 
-	"uniform sampler2D uTexGlyphs;"
+   "uniform sampler2D uTexGlyphs;"
+	"uniform sampler2D uTexBG;"
    "uniform vec4 uColour;"
+   "uniform float uSpread;"
 	"out vec4 FragColor;"
 	""
-	"in vec2 aTexCoords;"
+	"in vec4 aTexCoords;"
 	"in vec4 aColour;"
 	""
-	"in vec2 aWsp;"
-
+   "vec2 rand_hash22( vec2 p ){"
+      "vec3 p3 = fract(vec3(p.xyx) * 213.8976123);"
+      "p3 += dot(p3, p3.yzx+19.19);"
+      "return fract(vec2((p3.x + p3.y)*p3.z, (p3.x+p3.z)*p3.y));"
+   "}"
 	""
-	"void main()"
-	"{"
+	"void main(){"
 		"vec4 diffuse = aColour;"
 		
-		"if( diffuse.a == 0.0 )"
-		"{"
-			"diffuse.a = texture( uTexGlyphs, aTexCoords ).r;"
+      "vec4 avg = vec4(0.0);"
+
+		"if( aColour.a == 0.0 ){"
+         "avg = aColour;"
+			"avg.a = texture( uTexGlyphs, aTexCoords.xy ).r;"
 		"}"
-		
-		"FragColor = diffuse * uColour;"
+      "else{"
+         "if( uSpread > 0.0001 ){"
+            "for( int i=0; i<4; i ++ ){"
+               "vec2 spread = rand_hash22(aTexCoords.zw+vec2(float(i)));"
+               "avg += texture( uTexBG, aTexCoords.zw + (spread-0.5)*uSpread );"
+            "}"
+            "avg *= 0.25;"
+            "avg.a = 1.0;"
+            "avg.rgb = mix( avg.rgb, aColour.rgb, aColour.a );"
+         "}"
+         "else{"
+            "avg = aColour;"
+         "}"
+      "}"
+
+		"FragColor = avg * uColour;"
 	"}"
    }
 };
@@ -367,8 +385,9 @@ static struct vg_shader _shader_ui_image = {
 
 static void _vg_ui_init(void){
    if( !vg_shader_compile( &_shader_ui ) ||
-       !vg_shader_compile( &_shader_ui_image ) ) 
+       !vg_shader_compile( &_shader_ui_image ) ){
       vg_fatal_error( "Failed to compile ui shader" );
+   }
 
    /*
     * Vertex buffer
@@ -525,6 +544,14 @@ static void ui_flush( enum ui_shader shader, f32 w, f32 h ){
       glActiveTexture( GL_TEXTURE0 );
       glBindTexture( GL_TEXTURE_2D, vg_ui.tex_glyphs );
       glUniform1i( glGetUniformLocation( _shader_ui.id, "uTexGlyphs" ), 0 );
+
+      glActiveTexture( GL_TEXTURE1 );
+      glBindTexture( GL_TEXTURE_2D, vg_ui.tex_bg );
+      glUniform1i( glGetUniformLocation( _shader_ui.id, "uTexBG" ), 1 );
+      glUniform1f( glGetUniformLocation( _shader_ui.id, "uSpread" ), 
+                   vg_ui.frosting );
+      glUniform2fv( glGetUniformLocation( _shader_ui.id, "uBGInverseRatio" ),
+                     1, vg_ui.bg_inverse_ratio );
    }
    else if( shader == k_ui_shader_image ){
       glUseProgram( _shader_ui_image.id );
-- 
2.25.1