ascension: src/scene.c@df81d493716e

     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 void asc_scene_init(AscScene *scene) {

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

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

    55         return;

    56     }

    58     // zero everything, first

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

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

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

    64     // create the root node

    65     scene->root = asc_scene_node_empty();

    67     // initialize the render groups

    68     cx_array_initialize(scene->rg_sprites_opaque, 8);

    69     cx_array_initialize(scene->rg_sprites_blended, 8);

    70 }

    72 void asc_scene_destroy(AscScene *scene) {

    73     asc_scene_node_free(scene->root);

    74 }

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

    77     asc_scene_node_link(scene->root, node);

    78     asc_node_update(node);

    79 }

    81 #define asc_scene_draw_render_group(rg) \

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

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

    84     } (void)0

    86 #define asc_scene_draw_render_group_reversed(rg) \

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

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

    89     } (void)0

    91 void asc_scene_draw(AscScene *scene) {

    92     // reset render groups

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

    94     scene->rg_sprites_opaque_size = 0;

    95     scene->rg_sprites_blended_size = 0;

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

    98     CxTreeIterator iter = asc_scene_node_iterator(scene->root, false);

    99     cxIteratorNext(iter);

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

   102     cx_foreach(AscSceneNode*, node, iter) {

   103         node->depth = iter.depth;

   105         // execute behaviors, first

   106         AscBehaviorNode *behavior = node->behaviors;

   107         while (behavior) {

   108             behavior->func(node);

   109             behavior = behavior->next;

   110         }

   112         // check if geometry needs update

   113         if (node->need_graphics_update) {

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

   115             node->need_graphics_update = false;

   116             node->update_func(node);

   117         }

   118         if (node->need_transform_update) {

   119             assert(node->transform_update_func != NULL);

   120             node->need_transform_update = false;

   121             asc_transform_identity(node->local_transform);

   122             asc_transform_copy(node->world_transform, node->parent->world_transform);

   123             node->transform_update_func(node);

   124             asc_mat4f_mulst(node->final_transform, node->local_transform, node->world_transform);

   125         }

   127         // add to render group

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

   129             struct asc_render_group_entry entry = {

   130                     node->draw_func, node

   131             };

   132             switch (node->render_group) {

   133                 case ASC_RENDER_GROUP_SPRITE_OPAQUE:

   134                     cx_array_simple_add(scene->rg_sprites_opaque, entry);

   135                     break;

   136                 case ASC_RENDER_GROUP_SPRITE_BLEND:

   137                     cx_array_simple_add(scene->rg_sprites_blended, entry);

   138                     break;

   139             }

   140         }

   141     }

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

   144     glViewport(

   145             scene->viewport.pos.x,

   146             -scene->viewport.pos.y,

   147             scene->viewport.size.width,

   148             scene->viewport.size.height

   149     );

   150     glClear(GL_COLOR_BUFFER_BIT);

   152     // -----------------------------------------

   153     // process the render groups for each camera

   154     // -----------------------------------------

   155     cx_for_n(cam_id, ASC_SCENE_CAMERAS_MAX) {

   156         // update camera parameters, first

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

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

   159         camera->update(camera);

   161         // 2D Elements

   162         // ===========

   163         glEnable(GL_DEPTH_TEST);

   164         glClear(GL_DEPTH_BUFFER_BIT);

   166         // Sprites

   167         // -------

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

   169         glUseProgram(ASC_SHADER_SPRITE.base.id);

   170         glUniformMatrix4fv(ASC_SHADER_SPRITE.base.projection, 1,

   171                            GL_FALSE, camera->projection);

   173         // render opaque sprites from front to back

   174         glDisable(GL_BLEND);

   175         asc_scene_draw_render_group_reversed(scene->rg_sprites_opaque);

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

   177         glEnable(GL_BLEND);

   178         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   179         asc_scene_draw_render_group(scene->rg_sprites_blended);

   180     }

   181 }

   183 AscSceneNode *asc_scene_node_empty(void) {

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

   185     node->free_func = (asc_scene_free_func) free;

   186     asc_transform_identity(node->local_transform);

   187     asc_transform_identity(node->world_transform);

   188     asc_transform_identity(node->final_transform);

   189     return node;

   190 }

   192 void asc_scene_node_free(AscSceneNode *node) {

   193     if (node == NULL) return;

   195     // remove this node from its parent

   196     asc_scene_node_unlink(node);

   198     // free the entire subtree

   199     CxTreeIterator iter = asc_scene_node_iterator(node, true);

   200     cx_foreach(AscSceneNode*, child, iter) {

   201         if (!iter.exiting) continue;

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

   203             child->free_func(child);

   204         } else {

   205             free(child);

   206         }

   207     }

   208 }

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

   211     cx_tree_link(

   212             parent, node,

   213             offsetof(AscSceneNode, parent),

   214             offsetof(AscSceneNode, children),

   215             offsetof(AscSceneNode, prev),

   216             offsetof(AscSceneNode, next)

   217     );

   218 }

   220 void asc_scene_node_unlink(AscSceneNode *node) {

   221     cx_tree_unlink(

   222             node,

   223             offsetof(AscSceneNode, parent),

   224             offsetof(AscSceneNode, children),

   225             offsetof(AscSceneNode, prev),

   226             offsetof(AscSceneNode, next)

   227     );

   228 }

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

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

   232     behavior_node->func = behavior;

   233     cx_tree_link(

   234             node,

   235             behavior_node,

   236             offsetof(AscBehaviorNode, parent),

   237             offsetof(AscSceneNode, behaviors),

   238             offsetof(AscBehaviorNode, prev),

   239             offsetof(AscBehaviorNode, next)

   240     );

   241     return behavior_node;

   242 }

   244 void asc_scene_remove_behavior(AscBehaviorNode *node) {

   245     cx_tree_unlink(

   246             node,

   247             offsetof(AscBehaviorNode, parent),

   248             offsetof(AscSceneNode, behaviors),

   249             offsetof(AscBehaviorNode, prev),

   250             offsetof(AscBehaviorNode, next)

   251     );

   252 }

   254 void asc_node_update_transform(AscSceneNode *node) {

   255     CxTreeIterator iter = asc_scene_node_iterator(node, false);

   256     cx_foreach(AscSceneNode*, n, iter) {

   257         n->need_transform_update = true;

   258     }

   259 }

Mercurial > hg > ascension / file revision

src/scene.c@df81d493716e

src/scene.c