Waves generated with Perlin-type noise #8994

1 files changed, 53 insertions, 6 deletions

diff --git a/client/shaders/nodes_shader/opengl_vertex.glsl b/client/shaders/nodes_shader/opengl_vertex.glsl
index bbf7b1d65..f56aaefaa 100644
--- a/client/shaders/nodes_shader/opengl_vertex.glsl
+++ b/client/shaders/nodes_shader/opengl_vertex.glsl
@@ -46,6 +46,43 @@ float smoothTriangleWave(float x)
 	return smoothCurve(triangleWave(x)) * 2.0 - 1.0;
 }
 
+#if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_TRANSPARENT || \
+	MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_OPAQUE || \
+	MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_BASIC) && ENABLE_WAVING_WATER
+
+//
+// Simple, fast noise function.
+// See: https://gist.github.com/patriciogonzalezvivo/670c22f3966e662d2f83
+//
+vec4 perm(vec4 x)
+{
+	return mod(((x * 34.0) + 1.0) * x, 289.0);
+}
+
+float snoise(vec3 p)
+{
+	vec3 a = floor(p);
+	vec3 d = p - a;
+	d = d * d * (3.0 - 2.0 * d);
+
+	vec4 b = a.xxyy + vec4(0.0, 1.0, 0.0, 1.0);
+	vec4 k1 = perm(b.xyxy);
+	vec4 k2 = perm(k1.xyxy + b.zzww);
+
+	vec4 c = k2 + a.zzzz;
+	vec4 k3 = perm(c);
+	vec4 k4 = perm(c + 1.0);
+
+	vec4 o1 = fract(k3 * (1.0 / 41.0));
+	vec4 o2 = fract(k4 * (1.0 / 41.0));
+
+	vec4 o3 = o2 * d.z + o1 * (1.0 - d.z);
+	vec2 o4 = o3.yw * d.x + o3.xz * (1.0 - d.x);
+
+	return o4.y * d.y + o4.x * (1.0 - d.y);
+}
+
+#endif
 
 void main(void)
 {
@@ -65,7 +102,8 @@ void main(void)
 
 float disp_x;
 float disp_z;
-#if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES) || (MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS)
+#if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES) || \
+	(MATERIAL_TYPE == TILE_MATERIAL_WAVING_PLANTS && ENABLE_WAVING_PLANTS)
 	vec4 pos2 = mWorld * gl_Vertex;
 	float tOffset = (pos2.x + pos2.y) * 0.001 + pos2.z * 0.002;
 	disp_x = (smoothTriangleWave(animationTimer * 23.0 + tOffset) +
@@ -75,12 +113,22 @@ float disp_z;
 		smoothTriangleWave(animationTimer * 13.0 + tOffset)) * 0.5;
 #endif
 
+	worldPosition = (mWorld * gl_Vertex).xyz;
 
-#if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_OPAQUE || MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_BASIC) && ENABLE_WAVING_WATER
+#if (MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_TRANSPARENT || \
+	MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_OPAQUE || \
+	MATERIAL_TYPE == TILE_MATERIAL_WAVING_LIQUID_BASIC) && ENABLE_WAVING_WATER
+	// Generate waves with Perlin-type noise.
+	// The constants are calibrated such that they roughly
+	// correspond to the old sine waves.
 	vec4 pos = gl_Vertex;
-	pos.y -= 2.0;
-	float posYbuf = (pos.z / WATER_WAVE_LENGTH + animationTimer * WATER_WAVE_SPEED * WATER_WAVE_LENGTH);
-	pos.y -= sin(posYbuf) * WATER_WAVE_HEIGHT + sin(posYbuf / 7.0) * WATER_WAVE_HEIGHT;
+	vec3 wavePos = worldPosition + cameraOffset;
+	// The waves are slightly compressed along the z-axis to get
+	// wave-fronts along the x-axis.
+	wavePos.x /= WATER_WAVE_LENGTH * 3;
+	wavePos.z /= WATER_WAVE_LENGTH * 2;
+	wavePos.z += animationTimer * WATER_WAVE_SPEED * 10;
+	pos.y += (snoise(wavePos) - 1) * WATER_WAVE_HEIGHT * 5;
 	gl_Position = mWorldViewProj * pos;
 #elif MATERIAL_TYPE == TILE_MATERIAL_WAVING_LEAVES && ENABLE_WAVING_LEAVES
 	vec4 pos = gl_Vertex;
@@ -101,7 +149,6 @@ float disp_z;
 
 
 	vPosition = gl_Position.xyz;
-	worldPosition = (mWorld * gl_Vertex).xyz;
 
 	// Don't generate heightmaps when too far from the eye
 	float dist = distance (vec3(0.0, 0.0, 0.0), vPosition);