SSAO experiments (unfinihsed)

client/aux.js

@@ -265,3 +265,11 @@ function grid_snap_step(state) {
         return 32 / zoom_next;
     }
 }
+
+function canvas_css_rect(context) {
+    const el = context.canvas;
+    return {
+        'width': el.clientWidth,
+        'height': el.clientHeight
+    };
+}

client/bvh.js

@@ -220,8 +220,10 @@ function bvh_clip(state, context) {
 
     tv_clear(context.clipped_indices);
 
+    const canvas = canvas_css_rect(context);
+
     const screen_topleft     = screen_to_canvas(state, {'x': 0, 'y': 0});
-    const screen_bottomright = screen_to_canvas(state, {'x': context.canvas.width, 'y': context.canvas.height});
+    const screen_bottomright = screen_to_canvas(state, {'x': canvas.width, 'y': canvas.height});
     const screen_topright    = { 'x': screen_bottomright.x, 'y': screen_topleft.y };
     const screen_bottomleft  = { 'x': screen_topleft.x,     'y': screen_bottomright.y };
 

client/index.js

@@ -31,6 +31,7 @@ const config = {
     pattern_fadeout_min: 0.3,
     pattern_fadeout_max: 0.75,
     min_pressure: 50,
+    ssao: 0.5, 
     benchmark: {
         zoom_level: -75,
         offset: { x: 425, y: -1195 },

client/webgl_draw.js

@@ -86,6 +86,8 @@ async function draw(state, context, animate, ts) {
     const width = window.innerWidth;
     const height = window.innerHeight;
 
+    const canvas = canvas_css_rect(context);
+
     bvh_clip(state, context); 
 
     const segment_count = await geometry_write_instances(state, context);
@@ -100,10 +102,10 @@ async function draw(state, context, animate, ts) {
     }
 
     // Only clear once we have the data, this might not always be on the same frame?
-    gl.viewport(0, 0, context.canvas.width, context.canvas.height);
+    gl.viewport(0, 0, canvas.width, canvas.height);
     gl.clearColor(context.bgcolor.r, context.bgcolor.g, context.bgcolor.b, 1);
     gl.clearDepth(0.0);
-    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
+    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT | gl.STENCIL_BUFFER_BIT);
 
     // Draw the background pattern
     if (state.background_pattern === 'dots') {
@@ -116,7 +118,7 @@ async function draw(state, context, animate, ts) {
         gl.vertexAttribPointer(locations['a_center'], 2, gl.FLOAT, false, 2 * 4, 0);
         gl.vertexAttribDivisor(locations['a_center'], 1);
 
-        gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+        gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
         gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
         gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
 
@@ -124,11 +126,12 @@ async function draw(state, context, animate, ts) {
         const zoom_log2 = Math.log2(zoom);
         const zoom_previous = Math.pow(2, Math.floor(zoom_log2));
         const zoom_next = Math.pow(2, Math.ceil(zoom_log2));
+        const grid_step = 32;
 
         // Previous level
         {
             const one_dot = new Float32Array(geometry_gen_quad(0, 0, 1 / zoom_previous));
-            const dot_instances = new Float32Array(geometry_gen_fullscreen_grid(state, context, 32 / zoom_previous, 32 / zoom_previous));
+            const dot_instances = new Float32Array(geometry_gen_fullscreen_grid(state, context, grid_step / zoom_previous, grid_step / zoom_previous));
             const t = Math.min(1.0, 1.0 - (zoom / zoom_previous) / 2.0);
 
             gl.uniform1f(locations['u_fadeout'], t);
@@ -141,7 +144,7 @@ async function draw(state, context, animate, ts) {
 
         // Next level
         if (zoom_previous != zoom_next) {
-            const dot_instances = new Float32Array(geometry_gen_fullscreen_grid(state, context, 32 / zoom_next, 32 / zoom_next));
+            const dot_instances = new Float32Array(geometry_gen_fullscreen_grid(state, context, grid_step / zoom_next, grid_step / zoom_next));
             const t = Math.min(1.0, 1.0 - (zoom_next / zoom) / 2.0);
 
             gl.uniform1f(locations['u_fadeout'], t);
@@ -155,7 +158,7 @@ async function draw(state, context, animate, ts) {
         const zoom = state.canvas.zoom;
 
         let zoom_log8 = Math.log(zoom) / Math.log(8);
-        //if (zoom_log2 === Math.floor(zoom_log2)) {
+        //if (zoom_log2 === Math.floor(zoom_log2)) 
         //    zoom_log2 -= 0.001;
         //}
 
@@ -175,14 +178,14 @@ async function draw(state, context, animate, ts) {
         gl.vertexAttribPointer(locations['a_data'], 2, gl.FLOAT, false, 2 * 4, 0);
         gl.vertexAttribDivisor(locations['a_data'], 1);
 
-        gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+        gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
         gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
         gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
         gl.uniform1f(locations['u_fadeout'], 1.0);
 
         // Previous level (major lines)
         {
-            const grid_instances = new Float32Array(geometry_gen_fullscreen_grid_1d(state, context, 32 / zoom_previous, 32 / zoom_previous));
+            const grid_instances = new Float32Array(geometry_gen_fullscreen_grid_1d(state, context, grid_step / zoom_previous, grid_step / zoom_previous));
             let t = (zoom / zoom_previous - 1) / -7 + 1;
             t = 0.25;
 
@@ -196,7 +199,7 @@ async function draw(state, context, animate, ts) {
 
         // Next level (minor lines)
         {
-            const grid_instances = new Float32Array(geometry_gen_fullscreen_grid_1d(state, context, 32 / zoom_next, 32 / zoom_next));
+            const grid_instances = new Float32Array(geometry_gen_fullscreen_grid_1d(state, context, grid_step / zoom_next, grid_step / zoom_next));
             let t = (zoom_next / zoom - 1) / 7;
             t = Math.min(0.1, -t + 1); // slight fade-in
 
@@ -226,7 +229,7 @@ async function draw(state, context, animate, ts) {
         gl.vertexAttribPointer(locations['a_pos'], 2, gl.FLOAT, false, 2 * 4, 0);
 
         for (const entry of context.images) {
-            gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+            gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
             gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
             gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
             gl.uniform1i(locations['u_texture'], 0); // Only 1 active texture for each drawcall
@@ -266,7 +269,7 @@ async function draw(state, context, animate, ts) {
         gl.bindTexture(gl.TEXTURE_2D, context.textures['stroke_data']);
         upload_square_rgba16ui_texture(gl, context.stroke_data, config.stroke_texture_size);
 
-        gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+        gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
         gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
         gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
         gl.uniform1i(locations['u_stroke_count'], state.events.length);
@@ -274,6 +277,7 @@ async function draw(state, context, animate, ts) {
         gl.uniform1i(locations['u_stroke_data'], 0);
         gl.uniform1i(locations['u_stroke_texture_size'], config.stroke_texture_size);
         gl.uniform1f(locations['u_fixed_pixel_width'], 0);
+        gl.uniform2f(locations['u_ssao'], config.ssao, config.ssao);
 
         gl.enableVertexAttribArray(locations['a_a']);
         gl.enableVertexAttribArray(locations['a_b']);
@@ -326,7 +330,7 @@ async function draw(state, context, animate, ts) {
         gl.bindTexture(gl.TEXTURE_2D, context.textures['dynamic_stroke_data']);
         upload_square_rgba16ui_texture(gl, context.dynamic_stroke_data, config.dynamic_stroke_texture_size);
 
-        gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+        gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
         gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
         gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
             
@@ -335,6 +339,7 @@ async function draw(state, context, animate, ts) {
         gl.uniform1i(locations['u_stroke_data'], 0);
         gl.uniform1i(locations['u_stroke_texture_size'], config.dynamic_stroke_texture_size);
         gl.uniform1f(locations['u_fixed_pixel_width'], 0);
+        gl.uniform2f(locations['u_ssao'], config.ssao, config.ssao);
 
         gl.enableVertexAttribArray(locations['a_a']);
         gl.enableVertexAttribArray(locations['a_b']);
@@ -374,7 +379,7 @@ async function draw(state, context, animate, ts) {
         gl.bindTexture(gl.TEXTURE_2D, context.textures['ui']);
         upload_square_rgba16ui_texture(gl, handles.stroke_data, config.ui_texture_size);
 
-        gl.uniform2f(locations['u_res'], context.canvas.width, context.canvas.height);
+        gl.uniform2f(locations['u_res'], canvas.width, canvas.height);
         gl.uniform2f(locations['u_scale'], state.canvas.zoom, state.canvas.zoom);
         gl.uniform2f(locations['u_translation'], state.canvas.offset.x, state.canvas.offset.y);
         gl.uniform1i(locations['u_stroke_count'], 8);

client/webgl_shaders.js

@@ -12,6 +12,7 @@ const sdf_vs_src = `#version 300 es
     uniform int u_stroke_texture_size;
     uniform highp usampler2D u_stroke_data;
     uniform float u_fixed_pixel_width;
+    uniform vec2 u_ssao;
     
     out vec4 v_line;
     out vec2 v_texcoord;
@@ -62,8 +63,9 @@ const sdf_vs_src = `#version 300 es
         }
       
         vec2 pos = origin + normalize(outwards) * radius * 2.0 * max(a_pressure.x, a_pressure.y); // doubling is to account for max possible pressure
-        screen02 = (pos.xy * u_scale + u_translation) / u_res * 2.0 + outwards * pixel * apron;
-        v_texcoord = pos.xy + outwards * rscale;
+        screen02 = (pos.xy * u_scale + u_translation) / u_res * u_ssao * 2.0 + outwards * pixel * apron;
+        v_texcoord = pos.xy;
+       // v_texcoord = pos.xy + outwards * rscale;
         screen02.y = 2.0 - screen02.y;
         v_line = vec4(a_a, a_b);        
         v_thickness = radius * a_pressure; // pressure 0.5 is the "neutral" pressure
@@ -97,10 +99,20 @@ const sdf_fs_src = `#version 300 es
             float h = clamp(dot(pa, ba) / dot(ba, ba), 0.0, 1.0);
             float dist = length(v_texcoord - (a + ba * h)) - mix(v_thickness.x, v_thickness.y, h);
 
+/*
             float fade = 0.5 * length(fwidth(v_texcoord));
             float alpha = 1.0 - smoothstep(-fade, fade, dist);
+*/
 
-            FragColor = vec4(v_color * alpha, alpha);
+            float alpha = 1.0 - step(0.0, dist);
+            alpha = clamp(0.0, 1.0, alpha);
+
+            if (alpha == 0.0) {
+                discard;
+            } else {
+                alpha = 0.5;
+                FragColor = vec4(v_color * alpha, alpha);
+            }
         } else {
             FragColor = vec4(0.2, 0.0, 0.0, 0.2);
         }
@@ -273,7 +285,7 @@ function init_webgl(state, context) {
     context.gl = context.canvas.getContext('webgl2', {
         'preserveDrawingBuffer': true,
         'desynchronized': true,
-        'antialias': false,
+        'antialias': true,
     });
 
     const gl = context.gl;
@@ -282,7 +294,7 @@ function init_webgl(state, context) {
     gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
 
     gl.enable(gl.DEPTH_TEST);
-    gl.depthFunc(gl.GEQUAL);
+    gl.depthFunc(gl.NOTEQUAL);
 
     context.gpu_timer_ext = gl.getExtension('EXT_disjoint_timer_query_webgl2');
     if (context.gpu_timer_ext === null) {
@@ -334,7 +346,8 @@ function init_webgl(state, context) {
             'u_stroke_count':    gl.getUniformLocation(context.programs['sdf'].main, 'u_stroke_count'),
             'u_stroke_data':     gl.getUniformLocation(context.programs['sdf'].main, 'u_stroke_data'),
             'u_stroke_texture_size': gl.getUniformLocation(context.programs['sdf'].main, 'u_stroke_texture_size'),
-            'u_fixed_pixel_width': gl.getUniformLocation(context.programs['sdf'].main, 'u_fixed_pixel_width'),
+            'u_fixed_pixel_width':   gl.getUniformLocation(context.programs['sdf'].main, 'u_fixed_pixel_width'),
+            'u_ssao':                gl.getUniformLocation(context.programs['sdf'].main, 'u_ssao'),
         }
     };
 
@@ -411,8 +424,8 @@ function init_webgl(state, context) {
             height = Math.round(entry.contentBoxSize[0].blockSize * devicePixelRatio);
         }
 
-        context.canvas.width = width;
-        context.canvas.height = height;
+        context.canvas.width = width * config.ssao;
+        context.canvas.height = height * config.ssao;
 
         schedule_draw(state, context);
     }