diff options
| -rwxr-xr-x | slideshow/opengl/vortexVertexShader.glsl | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/slideshow/opengl/vortexVertexShader.glsl b/slideshow/opengl/vortexVertexShader.glsl index fb40e0f48ade..07a00f2aa534 100755 --- a/slideshow/opengl/vortexVertexShader.glsl +++ b/slideshow/opengl/vortexVertexShader.glsl @@ -62,9 +62,15 @@ void main( void ) // A semi-random number 0..1, different for neighbouring tiles. float fuzz = snoise(vec2(float(tileXIndex)/(numTiles.x-1), float(tileYIndex)/(numTiles.y-1))); + // Semi-random rotation direction, identical for tiles that rotate into each other's location + // so that they don't pass through each others in flight, which looks ugly. + float direction = (snoise(vec2(floor(abs(float(numTiles.x-1)/2-tileXIndex))/(float(numTiles.x-1)/2), float(tileYIndex)/(numTiles.y-1))) < 0.5 ? -1 : 1); + float startTime = float(tileXIndex)/(numTiles.x-1) * 0.5 + fuzz*0.2; float endTime = min(startTime + 0.5, 1.0); + const float ALMOST_ONE = 0.999; + if (time <= startTime) { // Still at start location, nothing needed @@ -73,9 +79,10 @@ void main( void ) else if (time > startTime && time <= endTime) { // Moving - float rotation = (time - startTime) / (endTime - startTime); + float rotation = direction * (time - startTime) / (endTime - startTime); - v = rotationMatrix(vec3(0, 1, 0), rotation*M_PI) * v; + // Avoid z fighting + v = rotationMatrix(vec3(0, 1, 0), max(min(rotation, ALMOST_ONE), -ALMOST_ONE)*M_PI) * v; v_textureSelect = float(rotation > 0.5 || rotation < -0.5); } @@ -83,7 +90,8 @@ void main( void ) { // At end location. Tile is 180 degrees rotated - v = rotationMatrix(vec3(0, 1, 0), M_PI) * v; + // Avoid z fighting + v = rotationMatrix(vec3(0, 1, 0), direction*ALMOST_ONE*M_PI) * v; v_textureSelect = 1; } |