ascension: src/scene.c@44457f6cb0a2

     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/linked_list.h>

    34 #include <cx/array_list.h>

    35 #include <cx/tree.h>

    36 #include <cx/utils.h>

    38 #include "ascension/shader.h"

    39 #include <GL/glew.h>

    41 #include <assert.h>

    43 static CxTreeIterator asc_scene_node_iterator(

    44         AscSceneNode *node,

    45         bool visit_on_exit

    46 ) {

    47     return cx_tree_iterator(

    48             node, visit_on_exit,

    49             offsetof(AscSceneNode, children),

    50             offsetof(AscSceneNode, next)

    51     );

    52 }

    54 static CxTreeVisitor asc_scene_node_visitor(AscSceneNode *node) {

    55     return cx_tree_visitor(node,

    56             offsetof(AscSceneNode, children),

    57             offsetof(AscSceneNode, next)

    58     );

    59 }

    61 struct asc_render_group_entry {

    62     asc_scene_draw_func draw;

    63     AscSceneNode const *node;

    64 };

    66 #define asc_draw_render_group(iter) \

    67     cx_foreach(struct asc_render_group_entry*, entry, iter) { \

    68         entry->draw(entry->node); \

    69     }

    71 void asc_scene_draw(AscSceneNode *root, asc_recti viewport, AscCamera *camera) {

    72     // create render groups

    73     CxList *render_group[ASC_RENDER_GROUP_COUNT];

    74     cx_for_n(i, ASC_RENDER_GROUP_COUNT) {

    75         render_group[i] = cxArrayListCreateSimple(

    76                 sizeof(struct asc_render_group_entry), 32);

    77     }

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

    80     CxTreeVisitor iter = asc_scene_node_visitor(root);

    81     cxIteratorNext(iter);

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

    84     cx_foreach(AscSceneNode*, node, iter) {

    85         node->depth = iter.depth;

    87         // execute behaviors, first

    88         if (node->behaviors != NULL) {

    89             CxIterator behavior_iter = cxListIterator(node->behaviors);

    90             cx_foreach(asc_scene_update_func, behavior, behavior_iter) {

    91                 behavior(node);

    92             }

    93         }

    95         // TODO: implement culling

    96         // TODO: implement a hidden flag (requires UCX tree-continue function)

    98         // check if geometry needs update

    99         if (node->need_graphics_update) {

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

   101             node->need_graphics_update = false;

   102             node->update_func(node);

   103         }

   104         if (node->need_transform_update) {

   105             node->need_transform_update = false;

   106             asc_transform_from_parts(

   107                     node->transform,

   108                     node->position,

   109                     node->scale,

   110                     node->rotation

   111             );

   112             asc_mat4f_mulst(

   113                     node->world_transform,

   114                     node->transform,

   115                     node->parent->world_transform

   116             );

   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             cxListAdd(render_group[node->render_group], &entry);

   125         }

   126     }

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

   129     glViewport(

   130             viewport.pos.x,

   131             -viewport.pos.y,

   132             viewport.size.width,

   133             viewport.size.height

   134     );

   136     // -------------------------

   137     // process the render groups

   138     // -------------------------

   139     AscShaderProgram *shader;

   140     CxIterator render_iter;

   142     // 2D Elements

   143     // ===========

   144     glEnable(GL_DEPTH_TEST);

   145     glClear(GL_DEPTH_BUFFER_BIT);

   147     // Sprites

   148     // -------

   149     // TODO: implement view matrix for 2D worlds

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

   151     glUseProgram(shader->id);

   152     glUniformMatrix4fv(shader->projection, 1,

   153                        GL_FALSE, camera->projection);

   155     // render opaque sprites from front to back

   156     glDisable(GL_BLEND);

   157     render_iter = cxListBackwardsIterator(render_group[ASC_RENDER_GROUP_SPRITE_OPAQUE]);

   158     asc_draw_render_group(render_iter);

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

   161     glEnable(GL_BLEND);

   162     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

   163     render_iter = cxListIterator(render_group[ASC_RENDER_GROUP_SPRITE_BLEND]);

   164     asc_draw_render_group(render_iter);

   166     // destroy render groups

   167     cx_for_n(i, ASC_RENDER_GROUP_COUNT) {

   168         cxListDestroy(render_group[i]);

   169     }

   170 }

   172 AscSceneNode *asc_scene_node_empty(void) {

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

   174     node->free_func = (asc_scene_free_func) free;

   175     asc_transform_identity(node->transform);

   176     asc_transform_identity(node->world_transform);

   177     return node;

   178 }

   180 void asc_scene_node_free(AscSceneNode *node) {

   181     if (node == NULL) return;

   183     // remove this node from its parent

   184     asc_scene_node_unlink(node);

   186     // free the entire subtree

   187     CxTreeIterator iter = asc_scene_node_iterator(node, true);

   188     cx_foreach(AscSceneNode*, child, iter) {

   189         if (!iter.exiting) continue;

   190         if (child->behaviors != NULL) {

   191             cxListDestroy(child->behaviors);

   192         }

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

   194             child->free_func(child);

   195         } else {

   196             free(child);

   197         }

   198     }

   199 }

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

   202     cx_tree_link(

   203             parent, node,

   204             offsetof(AscSceneNode, parent),

   205             offsetof(AscSceneNode, children),

   206             offsetof(AscSceneNode, prev),

   207             offsetof(AscSceneNode, next)

   208     );

   209 }

   211 void asc_scene_node_unlink(AscSceneNode *node) {

   212     cx_tree_unlink(

   213             node,

   214             offsetof(AscSceneNode, parent),

   215             offsetof(AscSceneNode, children),

   216             offsetof(AscSceneNode, prev),

   217             offsetof(AscSceneNode, next)

   218     );

   219 }

   221 void asc_scene_add_behavior(

   222         AscSceneNode *node,

   223         asc_scene_update_func behavior

   224 ) {

   225     if (node->behaviors == NULL) {

   226         node->behaviors = cxLinkedListCreateSimple(CX_STORE_POINTERS);

   227     }

   228     cxListAdd(node->behaviors, behavior);

   229 }

   231 void asc_scene_remove_behavior(

   232         AscSceneNode *node,

   233         asc_scene_update_func behavior

   234 ) {

   235     if (node->behaviors != NULL) {

   236         cxListFindRemove(node->behaviors, behavior);

   237     }

   238 }

   240 void asc_update_transform(AscSceneNode *node) {

   241     if (node->need_transform_update) return;

   243     CxTreeIterator iter = asc_scene_node_iterator(node, false);

   244     cx_foreach(AscSceneNode*, n, iter) {

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

   246         n->need_transform_update = true;

   247     }

   248 }

Mercurial > hg > ascension / file revision

src/scene.c@44457f6cb0a2

src/scene.c