ascension: src/scene.c@7cf310cc47cb

     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_none, 8);

    69     cx_array_initialize(scene->rg_fonts, 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 void asc_scene_draw(AscScene *scene) {

    87     // reset render groups

    88     scene->rg_none_size = 0;

    89     scene->rg_fonts_size = 0;

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

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

    93     cxIteratorNext(iter);

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

    96     cx_foreach(AscSceneNode*, node, iter) {

    97         // execute behaviors, first

    98         AscBehaviorNode *behavior = node->behaviors;

    99         while (behavior) {

   100             behavior->func(node);

   101             behavior = behavior->next;

   102         }

   104         // check if geometry needs update

   105         if (node->need_graphics_update) {

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

   107             node->need_graphics_update = false;

   108             node->update_func(node);

   109         }

   110         if (node->need_transform_update) {

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

   112             node->need_transform_update = false;

   113             asc_transform_identity(node->local_transform);

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

   115             node->transform_update_func(node);

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

   117         }

   119         // add to render group

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

   121             struct asc_render_group_entry entry = {

   122                     node->draw_func, node

   123             };

   124             switch (node->render_group) {

   125                 case ASC_RENDER_GROUP_NONE:

   126                     cx_array_simple_add(scene->rg_none, entry);

   127                     break;

   128                 case ASC_RENDER_GROUP_FONTS:

   129                     cx_array_simple_add(scene->rg_fonts, entry);

   130                     break;

   131             }

   132         }

   133     }

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

   136     glViewport(

   137             scene->viewport.pos.x,

   138             -scene->viewport.pos.y,

   139             scene->viewport.size.width,

   140             scene->viewport.size.height

   141     );

   143     // -----------------------------------------

   144     // process the render groups for each camera

   145     // -----------------------------------------

   146     cx_for_n(cam_id, ASC_SCENE_CAMERAS_MAX) {

   147         // update camera parameters, first

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

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

   150         camera->update(camera);

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

   153         glEnable(GL_DEPTH_TEST);

   154         glDisable(GL_BLEND);

   155         asc_scene_draw_render_group(scene->rg_none);

   157         // draw the FONTS group

   158         glDisable(GL_DEPTH_TEST);

   159         glEnable(GL_BLEND);

   160         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

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

   162         // TODO: compute render order for alpha blending to work correctly

   163         glUseProgram(ASC_SHADER_FONT.base.id);

   164         glUniformMatrix4fv(ASC_SHADER_FONT.base.projection, 1,

   165                            GL_FALSE, camera->projection);

   166         asc_scene_draw_render_group(scene->rg_fonts);

   167     }

   168 }

   170 AscSceneNode *asc_scene_node_empty(void) {

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

   172     node->free_func = (asc_scene_free_func) free;

   173     asc_transform_identity(node->local_transform);

   174     asc_transform_identity(node->world_transform);

   175     asc_transform_identity(node->final_transform);

   176     return node;

   177 }

   179 void asc_scene_node_free(AscSceneNode *node) {

   180     if (node == NULL) return;

   182     // remove this node from its parent

   183     asc_scene_node_unlink(node);

   185     // free the entire subtree

   186     CxTreeIterator iter = asc_scene_node_iterator(node, true);

   187     cx_foreach(AscSceneNode*, child, iter) {

   188         if (!iter.exiting) continue;

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

   190             child->free_func(child);

   191         } else {

   192             free(child);

   193         }

   194     }

   195 }

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

   198     cx_tree_link(

   199             parent, node,

   200             offsetof(AscSceneNode, parent),

   201             offsetof(AscSceneNode, children),

   202             offsetof(AscSceneNode, prev),

   203             offsetof(AscSceneNode, next)

   204     );

   205 }

   207 void asc_scene_node_unlink(AscSceneNode *node) {

   208     cx_tree_unlink(

   209             node,

   210             offsetof(AscSceneNode, parent),

   211             offsetof(AscSceneNode, children),

   212             offsetof(AscSceneNode, prev),

   213             offsetof(AscSceneNode, next)

   214     );

   215 }

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

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

   219     behavior_node->func = behavior;

   220     cx_tree_link(

   221             node,

   222             behavior_node,

   223             offsetof(AscBehaviorNode, parent),

   224             offsetof(AscSceneNode, behaviors),

   225             offsetof(AscBehaviorNode, prev),

   226             offsetof(AscBehaviorNode, next)

   227     );

   228     return behavior_node;

   229 }

   231 void asc_scene_remove_behavior(AscBehaviorNode *node) {

   232     cx_tree_unlink(

   233             node,

   234             offsetof(AscBehaviorNode, parent),

   235             offsetof(AscSceneNode, behaviors),

   236             offsetof(AscBehaviorNode, prev),

   237             offsetof(AscBehaviorNode, next)

   238     );

   239 }

   241 void asc_node_update_transform(AscSceneNode *node) {

   242     CxTreeIterator iter = asc_scene_node_iterator(node, false);

   243     cx_foreach(AscSceneNode*, n, iter) {

   244         n->need_transform_update = true;

   245     }

   246 }

Mercurial > hg > ascension / file revision

src/scene.c@7cf310cc47cb

src/scene.c