ascension: src/scene.c@18de2af03531

     1 /*

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

     3  * Copyright 2023 Mike Becker. All rights reserved.

     4  *

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

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

     7  *

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

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

    10  *

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

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

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

    14  *

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

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

    17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

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

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

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

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

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

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

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

    25  * POSSIBILITY OF SUCH DAMAGE.

    26  */

    28 #include "ascension/scene.h"

    29 #include "ascension/error.h"

    31 #include "ascension/context.h"

    33 #include <cx/tree.h>

    34 #include <cx/utils.h>

    36 #include "ascension/shader.h"

    37 #include <GL/glew.h>

    39 #include <assert.h>

    41 static CxTreeIterator asc_scene_node_iterator(

    42         AscSceneNode *node,

    43         bool visit_on_exit

    44 ) {

    45     return cx_tree_iterator(

    46             node, visit_on_exit,

    47             offsetof(AscSceneNode, children),

    48             offsetof(AscSceneNode, next)

    49     );

    50 }

    52 static CxTreeVisitor asc_scene_node_visitor(AscSceneNode *node) {

    53     return cx_tree_visitor(node,

    54             offsetof(AscSceneNode, children),

    55             offsetof(AscSceneNode, next)

    56     );

    57 }

    59 void asc_scene_init(AscScene *scene) {

    60     if (scene->root != NULL) {

    61         asc_error("Scene is already initialized.");

    62         return;

    63     }

    65     // zero everything, first

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

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

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

    71     // create the root node

    72     scene->root = asc_scene_node_empty();

    74     // initialize the render groups

    75     cx_array_initialize(scene->rg_sprites_opaque, 8);

    76     cx_array_initialize(scene->rg_sprites_blended, 8);

    77 }

    79 void asc_scene_destroy(AscScene *scene) {

    80     asc_scene_node_free(scene->root);

    81 }

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

    84     asc_scene_node_link(scene->root, node);

    85     asc_node_update(node);

    86 }

    88 #define asc_scene_draw_render_group(rg) \

    89     cx_for_n(i, rg##_size) { \

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

    91     } (void)0

    93 #define asc_scene_draw_render_group_reversed(rg) \

    94     for(size_t i = rg##_size ; i > 0 ; i--) { \

    95         rg[i-1].draw(rg[i-1].node); \

    96     } (void)0

    98 void asc_scene_draw(AscScene *scene) {

    99     // reset render groups

   100     // TODO: avoid recalculating the groups, if possible

   101     scene->rg_sprites_opaque_size = 0;

   102     scene->rg_sprites_blended_size = 0;

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

   105     CxTreeVisitor iter = asc_scene_node_visitor(scene->root);

   106     cxIteratorNext(iter);

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

   109     cx_foreach(AscSceneNode*, node, iter) {

   110         node->depth = iter.depth;

   112         // execute behaviors, first

   113         AscBehaviorNode *behavior = node->behaviors;

   114         while (behavior) {

   115             behavior->func(node);

   116             behavior = behavior->next;

   117         }

   119         // check if geometry needs update

   120         if (node->need_graphics_update) {

   121             assert(node->update_func != NULL);

   122             node->need_graphics_update = false;

   123             node->update_func(node);

   124         }

   125         if (node->need_transform_update) {

   126             node->need_transform_update = false;

   127             asc_transform_from_parts(

   128                     node->transform,

   129                     node->position,

   130                     node->scale,

   131                     node->rotation

   132             );

   133             asc_mat4f_mulst(

   134                     node->world_transform,

   135                     node->transform,

   136                     node->parent->world_transform

   137             );

   138         }

   140         // add to render group

   141         if (node->draw_func != NULL) {

   142             struct asc_render_group_entry entry = {

   143                     node->draw_func, node

   144             };

   145             switch (node->render_group) {

   146                 case ASC_RENDER_GROUP_SPRITE_OPAQUE:

   147                     cx_array_simple_add(scene->rg_sprites_opaque, entry);

   148                     break;

   149                 case ASC_RENDER_GROUP_SPRITE_BLEND:

   150                     cx_array_simple_add(scene->rg_sprites_blended, entry);

   151                     break;

   152             }

   153         }

   154     }

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

   157     glViewport(

   158             scene->viewport.pos.x,

   159             -scene->viewport.pos.y,

   160             scene->viewport.size.width,

   161             scene->viewport.size.height

   162     );

   163     glClear(GL_COLOR_BUFFER_BIT);

   165     // -----------------------------------------

   166     // process the render groups for each camera

   167     // -----------------------------------------

   168     AscShaderProgram *shader;

   169     cx_for_n(cam_id, ASC_SCENE_CAMERAS_MAX) {

   170         // update camera parameters, first

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

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

   173         camera->update(camera);

   175         // 2D Elements

   176         // ===========

   177         glEnable(GL_DEPTH_TEST);

   178         glClear(GL_DEPTH_BUFFER_BIT);

   180         // Sprites

   181         // -------

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

   183         shader = &asc_context.active_window->glctx.shader.sprite.base;

   184         glUseProgram(shader->id);

   185         glUniformMatrix4fv(shader->projection, 1,

   186                            GL_FALSE, camera->projection);

   188         // render opaque sprites from front to back

   189         glDisable(GL_BLEND);

   190         asc_scene_draw_render_group_reversed(scene->rg_sprites_opaque);

   191         // render sprites with alpha value from back to front

   192         glEnable(GL_BLEND);

   193         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   194         asc_scene_draw_render_group(scene->rg_sprites_blended);

   195     }

   196 }

   198 AscSceneNode *asc_scene_node_empty(void) {

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

   200     node->free_func = (asc_scene_free_func) free;

   201     asc_transform_identity(node->transform);

   202     asc_transform_identity(node->world_transform);

   203     return node;

   204 }

   206 void asc_scene_node_free(AscSceneNode *node) {

   207     if (node == NULL) return;

   209     // remove this node from its parent

   210     asc_scene_node_unlink(node);

   212     // free the entire subtree

   213     CxTreeIterator iter = asc_scene_node_iterator(node, true);

   214     cx_foreach(AscSceneNode*, child, iter) {

   215         if (!iter.exiting) continue;

   216         if (child->free_func != NULL) {

   217             child->free_func(child);

   218         } else {

   219             free(child);

   220         }

   221     }

   222 }

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

   225     cx_tree_link(

   226             parent, node,

   227             offsetof(AscSceneNode, parent),

   228             offsetof(AscSceneNode, children),

   229             offsetof(AscSceneNode, prev),

   230             offsetof(AscSceneNode, next)

   231     );

   232 }

   234 void asc_scene_node_unlink(AscSceneNode *node) {

   235     cx_tree_unlink(

   236             node,

   237             offsetof(AscSceneNode, parent),

   238             offsetof(AscSceneNode, children),

   239             offsetof(AscSceneNode, prev),

   240             offsetof(AscSceneNode, next)

   241     );

   242 }

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

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

   246     behavior_node->func = behavior;

   247     cx_tree_link(

   248             node,

   249             behavior_node,

   250             offsetof(AscBehaviorNode, parent),

   251             offsetof(AscSceneNode, behaviors),

   252             offsetof(AscBehaviorNode, prev),

   253             offsetof(AscBehaviorNode, next)

   254     );

   255     return behavior_node;

   256 }

   258 void asc_scene_remove_behavior(AscBehaviorNode *node) {

   259     cx_tree_unlink(

   260             node,

   261             offsetof(AscBehaviorNode, parent),

   262             offsetof(AscSceneNode, behaviors),

   263             offsetof(AscBehaviorNode, prev),

   264             offsetof(AscBehaviorNode, next)

   265     );

   266 }

   268 void asc_update_transform(AscSceneNode *node) {

   269     if (node->need_transform_update) return;

   271     CxTreeIterator iter = asc_scene_node_iterator(node, false);

   272     cx_foreach(AscSceneNode*, n, iter) {

   273         // TODO: break/continue when subtree is already marked for update

   274         n->need_transform_update = true;

   275     }

   276 }

Mercurial > hg > ascension / file revision

src/scene.c@18de2af03531

src/scene.c