finished shallow water sample

include/cute_draw.h

@@ -1301,6 +1301,7 @@ CF_INLINE void draw_quad_fill(Aabb bb, float chubbiness = 0) { cf_draw_quad_fill
 CF_INLINE void draw_quad_fill(v2 p0, v2 p1, v2 p2, v2 p3, float chubbiness = 0) { cf_draw_quad_fill2(p0, p1, p2, p3, chubbiness); }
 CF_INLINE void draw_box(Aabb bb, float thickness = 1.0f, float chubbiness = 0) { cf_draw_quad(bb, thickness, chubbiness); }
 CF_INLINE void draw_box(v2 p0, v2 p1, v2 p2, v2 p3, float thickness = 1.0f, float chubbiness = 0) { cf_draw_quad2(p0, p1, p2, p3, thickness, chubbiness); }
+CF_INLINE void draw_box(v2 p, float w, float h, float thickness = 1.0f, float chubbiness = 0) { cf_draw_quad(make_aabb(p, w, h), thickness, chubbiness); }
 CF_INLINE void draw_box_fill(Aabb bb, float chubbiness = 0) { cf_draw_quad_fill(bb, chubbiness); }
 CF_INLINE void draw_box_fill(v2 p0, v2 p1, v2 p2, v2 p3, float chubbiness = 0) { cf_draw_quad_fill2(p0, p1, p2, p3, chubbiness); }
 CF_INLINE void draw_circle(Circle circle, float thickness = 1.0f) { cf_draw_circle(circle, thickness); }

include/shaders/draw.glsl

@@ -335,7 +335,7 @@ float distance_triangle(vec2 p, vec2 a, vec2 b, vec2 c)
 		c = (!is_sprite && !is_text && !is_tri) ? sdf(c, v_col, d - v_radius) : c;
 
 		c *= v_alpha;
-		vec2 screen_position = (v_posH + vec2(1,1)) * 0.5;
+		vec2 screen_position = (v_posH + vec2(1,1)) * 0.5 * vec2(1,-1);
 		c = shader(c, v_pos, screen_position, v_user);
 		if (c.a == 0) discard;
 		result = c;

samples/shallow_water.cpp

@@ -13,6 +13,17 @@ void mount_content_directory_as(const char* dir)
 	fs_mount(path.c_str(), dir);
 }
 
+CF_Pixel* get_noise(int w, int h, float time)
+{
+	float scale = 2.5f;
+	float lacunarity = 2.0f;
+	int octaves = 3;
+	float falloff = 0.5f;
+	float frequency = 0.5f;
+	float time_amplitude = 0.05f;
+	return cf_noise_fbm_pixels_wrapped(w, h, 0, scale, lacunarity, octaves, falloff, time * frequency, time_amplitude);
+}
+
 int main(int argc, char* argv[])
 {
 	int options = APP_OPTIONS_DEFAULT_GFX_CONTEXT | APP_OPTIONS_WINDOW_POS_CENTERED | APP_OPTIONS_RESIZABLE;
@@ -22,8 +33,12 @@ int main(int argc, char* argv[])
 	mount_content_directory_as("/");
 	app_init_imgui();
 
+	int W = 160;
+	int H = 120;
+
 	CF_Shader shader = CF_MAKE_SOKOL_SHADER(shallow_water_shader);
 	CF_Canvas offscreen = make_canvas(canvas_defaults(160, 120));
+	CF_Canvas scene_canvas = make_canvas(canvas_defaults(160, 120));
 
 	struct Wavelet
 	{
@@ -35,33 +50,98 @@ int main(int argc, char* argv[])
 
 	Array<Wavelet> wavelets;
 
-	auto add_wavelet = [&](int x, int y) {
-		Wavelet w;
-		w.p = V2(x*0.25f - 80, (-y+480)*0.25f - 60);
-		wavelets.add(w);
+	struct Spawner
+	{
+		v2 p = V2(0,0);
+		int count = 3;
+		float opacity = 1.0f;
+		Routine rt = { };
+	};
+
+	Array<Spawner> spawners;
+
+	auto add_wavelet = [&](v2 p, float opacity) {
+		Wavelet& w = wavelets.add();
+		w.p = p;
+		w.opacity = opacity;
+	};
+
+	auto add_spawner = [&](int x, int y) {
+		Spawner& s = spawners.add();
+		s.p = V2(x*0.25f - 80, (-y+480)*0.25f - 60);
 	};
 
+	float time = 0;
+	CF_TextureParams tex_params = texture_defaults(W, H);
+	tex_params.usage = USAGE_TYPE_STREAM;
+	CF_Texture noise_tex = make_texture(tex_params);
+	CF_Sprite scene = make_sprite("/scene.ase");
+
 	while (app_is_running()) {
+		time += CF_DELTA_TIME;
+		CF_Pixel* noise = get_noise(W, H, time);
+		update_texture(noise_tex, noise, sizeof(CF_Pixel) * W * H);
+		cf_free(noise);
+
 		app_update();
 		camera_dimensions(160, 120);
 
+		ImGui::Begin("Shallow Water Sample");
+		static bool show_noise;
+		ImGui::Checkbox("Show noise", &show_noise);
+		static bool show_normals;
+		ImGui::Checkbox("Show normals", &show_normals);
+		ImGui::End();
+
 		if (mouse_just_pressed(MOUSE_BUTTON_LEFT)) {
-			add_wavelet(mouse_x(), mouse_y());
+			add_spawner(mouse_x(), mouse_y());
 		}
 
-		for (int i = 0; i < wavelets.size(); ++i) {
+		for (int i = 0; i < spawners.size(); ++i) {
+			Spawner& s = spawners[i];
+			s.opacity = max(0.0f, s.opacity - 0.6f * CF_DELTA_TIME);
+
+			rt_begin(s.rt, CF_DELTA_TIME)
+			{
+				add_wavelet(s.p, s.opacity);
+				s.count--;
+				if (!s.count) {
+					spawners.unordered_remove(i--);
+				}
+			}
+			rt_wait(0.75f)
+			{
+				nav_restart();
+			}
+			rt_end();
+		}
+
+		for (int i = 0; i < wavelets.count(); ++i) {
 			Wavelet& w = wavelets[i];
 			draw_push_antialias_scale(w.blur);
 			draw_push_color(make_color(1.0f, 1.0f, 1.0f, w.opacity));
 			draw_circle(w.p, w.r, 0);
 			w.r += 10.0f * CF_DELTA_TIME;
-			w.opacity -= 0.5f * CF_DELTA_TIME;
+			w.opacity -= 0.4f * CF_DELTA_TIME;
 			w.blur += 20.0f * CF_DELTA_TIME;
 			if (w.opacity < 0) {
-				wavelets.unordered_remove(i++);
+				wavelets.unordered_remove(i--);
 			}
 		}
 
+		render_to(offscreen, true);
+
+		draw_sprite(scene);
+		render_to(scene_canvas, true);
+
+		render_settings_push_shader(shader);
+		render_settings_push_texture("wavelets_tex", canvas_get_target(offscreen));
+		render_settings_push_texture("noise_tex", noise_tex);
+		render_settings_push_texture("scene_tex", canvas_get_target(scene_canvas));
+		render_settings_push_uniform("show_noise", show_noise ? 1.0f : 0.0f);
+		render_settings_push_uniform("show_normals", show_normals ? 1.0f : 0.0f);
+		draw_push_antialias(false);
+		draw_box(V2(0,0), (float)W, (float)H);
 		app_draw_onto_screen();
 	}
 

samples/shallow_water_data/shallow_water.glsl

@@ -5,24 +5,42 @@
 @ctype vec2 CF_V2
 
 @block shader_block
-uniform sampler2D water_tex;
+uniform sampler2D wavelets_tex;
 uniform sampler2D noise_tex;
+uniform sampler2D scene_tex;
 
 uniform shader_uniforms {
-	float amplitude;
-	float time;
+	float show_normals;
 	float show_noise;
 };
 
+vec2 normal_from_heightmap(sampler2D tex, vec2 uv)
+{
+	float ha = textureOffset(tex, uv, ivec2(-1, 1)).r;
+	float hb = textureOffset(tex, uv, ivec2( 1, 1)).r;
+	float hc = textureOffset(tex, uv, ivec2( 0,-1)).r;
+	vec2 n = vec2(ha-hc, hb-hc);
+	return n;
+}
+
+vec4 normal_to_color(vec2 n)
+{
+	return vec4(n * 0.5 + 0.5, 1.0, 1.0);
+}
+
 vec4 shader(vec4 color, vec2 pos, vec2 uv, vec4 params)
 {
-	vec2 noise_uv = uv;
-	noise_uv.x *= 640.0 / 128.0;
-	noise_uv.y *= 480.0 / 128.0;
-	vec4 noise_c = vec4(texture(noise_tex, noise_uv * 0.5 + time).r - 0.5);
-	vec2 offset = vec2(1.0/640.0, 1.0/480.0) * noise_c.r * amplitude;
-	vec4 c = texture(water_tex, uv + offset);
-	c = show_noise > 0 ? noise_c + 0.5 : c;
+	vec2 dim = vec2(1.0/160.0,1.0/120.0);
+	vec2 n = normal_from_heightmap(noise_tex, uv);
+	vec2 w = normal_from_heightmap(wavelets_tex, uv+n*dim*10.0);
+	vec4 c = mix(normal_to_color(n), normal_to_color(w), 0.25);
+	c = texture(scene_tex, uv+(n+w)*dim*10.0);
+	c = mix(c, vec4(1), length(n+w) > 0.2 ? 0.1 : 0.0);
+
+	c = show_normals > 0.0 ? mix(normal_to_color(n), normal_to_color(w), 0.25) : c;
+
+	c = show_noise > 0.0 ? texture(noise_tex, uv) : c;
+
 	return c;
 }
 @end