diff --git a/tutorial/03_noise.lolfx b/tutorial/03_noise.lolfx index ef9b2d85..de81f956 100644 --- a/tutorial/03_noise.lolfx +++ b/tutorial/03_noise.lolfx @@ -6,8 +6,7 @@ uniform float u_Time; attribute vec2 in_Position; -varying vec2 pass_Position; -varying mat2 pass_Rotation; +varying vec4 pass_Position; varying vec3 water[4]; varying vec3 fire[4]; @@ -30,13 +29,15 @@ void main(void) /* Noise sampling points for fire */ p_pos = 16.0 * p_pos - r * vec3(0.0, mod289(u_Time) * 128.0, 0.0); - fire[0] = p_pos / 2.0 + p_time; - fire[1] = p_pos / 4.0 + p_time; + fire[0] = p_pos / 2.0 + p_time * 2.0; + fire[1] = p_pos / 4.0 + p_time * 1.5; fire[2] = p_pos / 8.0 + p_time; fire[3] = p_pos / 16.0 + p_time; - pass_Position = in_Position; - pass_Rotation = mat2(cos(u_Time), sin(u_Time), -sin(u_Time), cos(u_Time)); + /* Pass rotated screen coordinates */ + pass_Position.xy = in_Position; + mat2 rot = mat2(cos(u_Time), sin(u_Time), -sin(u_Time), cos(u_Time)); + pass_Position.zw = rot * in_Position; gl_Position = vec4(in_Position, 0.0, 1.0); } @@ -47,8 +48,7 @@ void main(void) uniform float u_Time; -varying vec2 pass_Position; -varying mat2 pass_Rotation; +varying vec4 pass_Position; varying vec3 water[4]; varying vec3 fire[4]; @@ -87,15 +87,13 @@ float noise3d(vec3 p) void main(void) { - vec2 tmp = pass_Rotation * pass_Position; - float test = tmp.x * tmp.y + sin(3.0 * u_Time); - - /* Add some garbage noise */ - vec2 d = vec2(16.0, 9.0) * pass_Position; + /* Dither the transition between water and fire */ + float test = pass_Position.z * pass_Position.w + sin(2.0 * u_Time); + vec2 d = vec2(16.0, 9.0) * pass_Position.xy; test += 0.5 * (length(fract(d) - 0.5) - length(fract(d + 0.5) - 0.5)); + /* Compute 4 octaves of noise */ vec3 points[4] = (test > 0.0) ? fire : water; - vec4 n = vec4(noise3d(points[0]), noise3d(points[1]), noise3d(points[2]), @@ -105,9 +103,10 @@ void main(void) if (test > 0.0) { + /* Use noise results for fire */ float p = dot(n, vec4(0.125, 0.125, 0.25, 0.5)); - /* Fade out by adding [-.5,.5] */ + /* Fade to black on top of screen */ p -= pass_Position.y * 0.8 + 0.25; p = max(p, 0.0); p = min(p, 1.0); @@ -121,6 +120,7 @@ void main(void) } else { + /* Use noise results for water */ float p = dot(abs(2.0 * n - 1.0), vec4(0.5, 0.25, 0.125, 0.125)); float q = sqrt(p);