From: Stuart Buchanan Date: Wed, 5 Dec 2012 22:10:45 +0000 (+0000) Subject: Fix RNG so it is passed in from above rather than generating the same X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=66786651b0af97301b9932bc2e387dfbdb63e0c2;p=simgear.git Fix RNG so it is passed in from above rather than generating the same seed continuously. --- diff --git a/simgear/scene/sky/newcloud.cxx b/simgear/scene/sky/newcloud.cxx index 503e1de7..18b7710c 100644 --- a/simgear/scene/sky/newcloud.cxx +++ b/simgear/scene/sky/newcloud.cxx @@ -70,11 +70,11 @@ EffectMap effectMap; float SGNewCloud::sprite_density = 1.0; -SGNewCloud::SGNewCloud(const SGPath &texture_root, const SGPropertyNode *cld_def) +SGNewCloud::SGNewCloud(const SGPath &texture_root, const SGPropertyNode *cld_def, mt* s) { - // Set up a RNG that is repeatable within 10 minutes to ensure that clouds - // are synced up in multi-process deployments. - mt_init_time_10(&seed); + // Set up the RNG with the passed in seed. This allows us to make the RNG repeatable + // if required. + seed = s; min_width = cld_def->getFloatValue("min-cloud-width-m", 500.0); max_width = cld_def->getFloatValue("max-cloud-width-m", min_width*2); @@ -135,7 +135,7 @@ SGNewCloud::~SGNewCloud() { #if 0 // return a random number between -n/2 and n/2, tending to 0 static float Rnd(float n) { - return n * (-0.5f + (mt_rand(&seed) + mt_rand(&seed)) / 2.0f); + return n * (-0.5f + (mt_rand(seed) + mt_rand(seed)) / 2.0f); } #endif @@ -146,17 +146,17 @@ osg::ref_ptr SGNewCloud::genCloud() { // Determine how big this specific cloud instance is. Note that we subtract // the sprite size because the width/height is used to define the limits of // the center of the sprites, not their edges. - float width = min_width + mt_rand(&seed) * (max_width - min_width) - min_sprite_width; - float height = min_height + mt_rand(&seed) * (max_height - min_height) - min_sprite_height; + float width = min_width + mt_rand(seed) * (max_width - min_width) - min_sprite_width; + float height = min_height + mt_rand(seed) * (max_height - min_height) - min_sprite_height; if (width < 0.0) { width = 0.0; } if (height < 0.0) { height = 0.0; } // Determine appropriate shading factors - float top_factor = min_top_lighting_factor + mt_rand(&seed) * (max_top_lighting_factor - min_top_lighting_factor); - float middle_factor = min_middle_lighting_factor + mt_rand(&seed) * (max_middle_lighting_factor - min_middle_lighting_factor); - float bottom_factor = min_bottom_lighting_factor + mt_rand(&seed) * (max_bottom_lighting_factor - min_bottom_lighting_factor); - float shade_factor = min_shade_lighting_factor + mt_rand(&seed) * (max_shade_lighting_factor - min_shade_lighting_factor); + float top_factor = min_top_lighting_factor + mt_rand(seed) * (max_top_lighting_factor - min_top_lighting_factor); + float middle_factor = min_middle_lighting_factor + mt_rand(seed) * (max_middle_lighting_factor - min_middle_lighting_factor); + float bottom_factor = min_bottom_lighting_factor + mt_rand(seed) * (max_bottom_lighting_factor - min_bottom_lighting_factor); + float shade_factor = min_shade_lighting_factor + mt_rand(seed) * (max_shade_lighting_factor - min_shade_lighting_factor); //printf("Cloud: %2f, %2f, %2f, %2f\n", top_factor, middle_factor, bottom_factor, shade_factor); @@ -176,7 +176,7 @@ osg::ref_ptr SGNewCloud::genCloud() { float cull_distance_squared = min_sprite_height * min_sprite_height * 0.1f; // The number of sprites we actually use is a function of the (user-controlled) density - int n_sprites = num_sprites * sprite_density * (0.5f + mt_rand(&seed)); + int n_sprites = num_sprites * sprite_density * (0.5f + mt_rand(seed)); for (int i = 0; i < n_sprites; i++) { @@ -194,16 +194,16 @@ osg::ref_ptr SGNewCloud::genCloud() { y = 0; z = height * 0.5; } else { - float theta = mt_rand(&seed) * SGD_2PI; - float elev = mt_rand(&seed) * SGD_PI; + float theta = mt_rand(seed) * SGD_2PI; + float elev = mt_rand(seed) * SGD_PI; x = width * cos(theta) * 0.5f * sin(elev); y = width * sin(theta) * 0.5f * sin(elev); z = height * cos(elev) * 0.5f + height * 0.5f; } // Determine the height and width - float sprite_width = min_sprite_width + mt_rand(&seed) * (max_sprite_width - min_sprite_width); - float sprite_height = min_sprite_height + mt_rand(&seed) * (max_sprite_height - min_sprite_height); + float sprite_width = min_sprite_width + mt_rand(seed) * (max_sprite_width - min_sprite_width); + float sprite_height = min_sprite_height + mt_rand(seed) * (max_sprite_height - min_sprite_height); // Sprites are never taller than square. if (sprite_height > sprite_width ) @@ -226,10 +226,10 @@ osg::ref_ptr SGNewCloud::genCloud() { } // Determine the sprite texture indexes. - int index_x = (int) floor(mt_rand(&seed) * num_textures_x); + int index_x = (int) floor(mt_rand(seed) * num_textures_x); if (index_x >= num_textures_x) { index_x = num_textures_x - 1; } - int index_y = (int) floor(mt_rand(&seed) * num_textures_y); + int index_y = (int) floor(mt_rand(seed) * num_textures_y); if (height_map_texture) { // The y index depends on the position of the sprite within the cloud. diff --git a/simgear/scene/sky/newcloud.hxx b/simgear/scene/sky/newcloud.hxx index fd7c905a..88edf19c 100644 --- a/simgear/scene/sky/newcloud.hxx +++ b/simgear/scene/sky/newcloud.hxx @@ -41,7 +41,7 @@ using std::vector; class SGNewCloud { public: - SGNewCloud(const SGPath &texture_root, const SGPropertyNode *cld_def); + SGNewCloud(const SGPath &texture_root, const SGPropertyNode *cld_def, mt* s); ~SGNewCloud(); @@ -103,7 +103,7 @@ private: static float sprite_density; // RNG seed for this cloud - mt seed; + mt* seed; osg::Geometry* createOrthQuad(float w, float h, int varieties_x, int varieties_y); };