Mercurial > hg > ascension / file revision

 /*

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

  * Copyright 2023 Mike Becker. All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   1. Redistributions of source code must retain the above copyright

  *      notice, this list of conditions and the following disclaimer.

  *

  *   2. Redistributions in binary form must reproduce the above copyright

  *      notice, this list of conditions and the following disclaimer in the

  *      documentation and/or other materials provided with the distribution.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  */

 #include "ascension/scene.h"

 #include "ascension/error.h"

 #include "ascension/context.h"

 #include <cx/tree.h>

 #include <cx/utils.h>

 #include "ascension/shader.h"

 #include <GL/glew.h>

 #include <assert.h>

 void asc_scene_init(AscScene *scene) {

     if (scene->root != NULL) {

         asc_error("Scene is already initialized.");

         return;

     }

     // zero everything, first

     memset(scene, 0, sizeof(AscScene));

     // default viewport is the entire viewport of the active window

     scene->viewport.size = asc_context.active_window->dimensions;

     // create the root node

     scene->root = asc_scene_node_empty();

     // initialize the render groups

     cx_array_initialize(scene->rg_none, 8);

     cx_array_initialize(scene->rg_fonts, 8);

 }

 void asc_scene_destroy(AscScene *scene) {

     asc_scene_node_free(scene->root);

 }

 void asc_scene_add(AscScene *scene, AscSceneNode *node) {

     asc_scene_node_link(scene->root, node);

     asc_node_update(node);

 }

 #define asc_scene_draw_render_group(rg) \

     cx_for_n(i, rg##_size) { \

         rg[i].draw(rg[i].node); \

     } (void)0

 void asc_scene_draw(AscScene *scene) {

     // reset render groups

     scene->rg_none_size = 0;

     scene->rg_fonts_size = 0;

     // skip the root node deliberately, we know it's just the container

     CxTreeIterator iter = cx_tree_iterator(

             scene->root, false,

             offsetof(AscSceneNode, children),

             offsetof(AscSceneNode, next)

     );

     cxIteratorNext(iter);

     // update the children and add them to the render groups

     cx_foreach(AscSceneNode*, node, iter) {

         // execute behaviors, first

         AscBehaviorNode *behavior = node->behaviors;

         while (behavior) {

             behavior->func(node);

             behavior = behavior->next;

         }

         // check if geometry needs update

         if (node->need_full_update) {

             assert(node->update_func != NULL);

             node->need_full_update = false;

             node->update_func(node);

         }

         if (node->need_transform_update) {

             assert(node->transform_update_func != NULL);

             node->need_transform_update = false;

             asc_transform_identity(node->transform);

             node->transform_update_func(node);

         }

         // add to render group

         if (node->draw_func != NULL) {

             struct asc_render_group_entry entry = {

                     node->draw_func, node

             };

             switch (node->render_group) {

                 case ASC_RENDER_GROUP_NONE:

                     cx_array_simple_add(scene->rg_none, entry);

                     break;

                 case ASC_RENDER_GROUP_FONTS:

                     cx_array_simple_add(scene->rg_fonts, entry);

                     break;

             }

         }

     }

     // set the viewport (in OpenGL we need to invert the Y axis)

     glViewport(

             scene->viewport.pos.x,

             -scene->viewport.pos.y,

             scene->viewport.size.width,

             scene->viewport.size.height

     );

     // -----------------------------------------

     // process the render groups for each camera

     // -----------------------------------------

     cx_for_n(cam_id, ASC_SCENE_CAMERAS_MAX) {

         // update camera parameters, first

         AscCamera *camera = &scene->cameras[cam_id];

         if (camera->update == NULL) continue;

         camera->update(camera);

         // for the NONE group, the draw func is expected to do everything

         asc_scene_draw_render_group(scene->rg_none);

         // draw the FONTS group

         // TODO: see if we can really always ignore the view matrix

         glUseProgram(ASC_SHADER_FONT.base.id);

         glUniformMatrix4fv(ASC_SHADER_FONT.base.projection, 1,

                            GL_FALSE, camera->projection);

         asc_scene_draw_render_group(scene->rg_fonts);

     }

 }

 AscSceneNode *asc_scene_node_empty(void) {

     AscSceneNode *node = calloc(1, sizeof(AscSceneNode));

     node->free_func = (asc_scene_free_func) free;

     asc_transform_identity(node->transform);

     return node;

 }

 void asc_scene_node_free(AscSceneNode *node) {

     if (node == NULL) return;

     // remove this node from its parent

     asc_scene_node_unlink(node);

     // free the entire subtree

     CxTreeIterator iter = cx_tree_iterator(

             node, true,

             offsetof(AscSceneNode, children),

             offsetof(AscSceneNode, next)

     );

     cx_foreach(AscSceneNode*, child, iter) {

         if (!iter.exiting) continue;

         if (child->free_func != NULL) {

             child->free_func(child);

         } else {

             free(child);

         }

     }

 }

 void asc_scene_node_link(AscSceneNode * restrict parent, AscSceneNode * restrict node) {

     cx_tree_link(

             parent, node,

             offsetof(AscSceneNode, parent),

             offsetof(AscSceneNode, children),

             offsetof(AscSceneNode, prev),

             offsetof(AscSceneNode, next)

     );

 }

 void asc_scene_node_unlink(AscSceneNode *node) {

     cx_tree_unlink(

             node,

             offsetof(AscSceneNode, parent),

             offsetof(AscSceneNode, children),

             offsetof(AscSceneNode, prev),

             offsetof(AscSceneNode, next)

     );

 }

 AscBehaviorNode *asc_scene_add_behavior(AscSceneNode *node, asc_scene_update_func behavior) {

     AscBehaviorNode *behavior_node = calloc(1, sizeof(AscBehaviorNode));

     behavior_node->func = behavior;

     cx_tree_link(

             node,

             behavior_node,

             offsetof(AscBehaviorNode, parent),

             offsetof(AscSceneNode, behaviors),

             offsetof(AscBehaviorNode, prev),

             offsetof(AscBehaviorNode, next)

     );

     return behavior_node;

 }

 void asc_scene_remove_behavior(AscBehaviorNode *node) {

     cx_tree_unlink(

             node,

             offsetof(AscBehaviorNode, parent),

             offsetof(AscSceneNode, behaviors),

             offsetof(AscBehaviorNode, prev),

             offsetof(AscBehaviorNode, next)

     );

 }