universe@0: /*
universe@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@0:  * Copyright 2023 Mike Becker. All rights reserved.
universe@0:  *
universe@0:  * Redistribution and use in source and binary forms, with or without
universe@0:  * modification, are permitted provided that the following conditions are met:
universe@0:  *
universe@0:  *   1. Redistributions of source code must retain the above copyright
universe@0:  *      notice, this list of conditions and the following disclaimer.
universe@0:  *
universe@0:  *   2. Redistributions in binary form must reproduce the above copyright
universe@0:  *      notice, this list of conditions and the following disclaimer in the
universe@0:  *      documentation and/or other materials provided with the distribution.
universe@0:  *
universe@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@0:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@0:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@0:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@0:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@0:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@0:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@0:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@0:  * POSSIBILITY OF SUCH DAMAGE.
universe@0:  */
universe@0: 
universe@0: #include "ascension/core.h"
universe@0: #include "ascension/utils.h"
universe@0: 
universe@0: #include <cx/linked_list.h>
universe@0: #include <cx/printf.h>
universe@0: 
universe@0: static void asc_gl_debug_callback(
universe@0:         GLenum source, GLenum type, GLuint id, GLenum severity,
universe@0:         GLsizei length, const GLchar* message,
universe@0:         const void* userParam
universe@0: ) {
universe@0:     cxmutstr buf = cx_asprintf(
universe@0:             "source = %d, id = %u, type = %d, severity= %d, message = %.*s",
universe@0:             source, id, type, severity, length, message);
universe@0:     if (type == GL_DEBUG_TYPE_ERROR) {
universe@0:         asc_error(buf.ptr);
universe@0:     } else {
universe@0:         asc_dprintf("GL debug: %*.s", (int)buf.length, buf.ptr);
universe@0:     }
universe@0:     cx_strfree(&buf);
universe@0: }
universe@0: 
universe@0: AscContext asc_context;
universe@0: 
universe@0: // forward declarations
universe@0: static void asc_window_destroy_impl(AscWindow* window);
universe@0: 
universe@0: void asc_context_initialize(void) {
universe@0:     if (asc_test_flag(asc_context.flags, ASC_FLAG_INITILIZED))
universe@0:         return;
universe@0:     asc_clear_flag(&asc_context.flags, ASC_FLAG_HAS_ERROR);
universe@0: 
universe@0:     // initialize error buffer
universe@0:     cxBufferInit(
universe@0:             &asc_context.error_buffer,
universe@0:             NULL,
universe@0:             256,
universe@0:             NULL,
universe@0:             CX_BUFFER_AUTO_EXTEND
universe@0:     );
universe@0: 
universe@0:     // initialize lists
universe@0:     asc_context.windows = cxLinkedListCreateSimple(CX_STORE_POINTERS);
universe@0:     asc_context.windows->simple_destructor =
universe@0:             (cx_destructor_func)asc_window_destroy_impl;
universe@0: 
universe@0:     // initialize SDL
universe@0:     if (SDL_Init(SDL_INIT_VIDEO) < 0) {
universe@0:         asc_error(SDL_GetError());
universe@0:     } else {
universe@0:         if (TTF_Init() < 0) {
universe@0:             asc_error(TTF_GetError());
universe@0:         }
universe@0:     }
universe@0:     SDL_ClearError();
universe@0:     asc_set_flag(&asc_context.flags, ASC_FLAG_INITILIZED);
universe@0:     asc_dprintf("Ascension context initialized.");
universe@0: }
universe@0: 
universe@0: void asc_context_destroy(void) {
universe@0:     // destroy lists
universe@0:     cxListDestroy(asc_context.windows);
universe@0: 
universe@0:     // quit SDL
universe@0:     if (TTF_WasInit())
universe@0:         TTF_Quit();
universe@0:     SDL_Quit();
universe@0: 
universe@0:     // destroy the error buffer
universe@0:     cxBufferDestroy(&asc_context.error_buffer);
universe@0:     asc_context.flags = 0;
universe@0:     asc_dprintf("Ascension context destroyed.");
universe@0: }
universe@0: 
universe@0: void asc_error_cchar(char const* text) {
universe@0:     asc_error_cxstr(cx_str(text));
universe@0: }
universe@0: 
universe@0: void asc_error_cuchar(unsigned char const* text) {
universe@0:     asc_error_cxstr(cx_str((char const*)text));
universe@0: }
universe@0: 
universe@0: void asc_error_cxstr(cxstring text) {
universe@0:     if (text.length == 0) return;
universe@0: 
universe@0:     // write error to debug output
universe@0:     asc_dprintf("ERROR: %*.s", (int)text.length, text.ptr);
universe@0: 
universe@0:     // write error to buffer
universe@0:     CxBuffer* buf = &asc_context.error_buffer;
universe@0:     cxBufferWrite(text.ptr, 1, text.length, buf);
universe@0:     cxBufferPut(buf, '\n');
universe@0: 
universe@0:     asc_set_flag(&asc_context.flags, ASC_FLAG_HAS_ERROR);
universe@0: }
universe@0: 
universe@0: bool asc_has_error(void) {
universe@0:     return asc_test_flag(asc_context.flags, ASC_FLAG_HAS_ERROR);
universe@0: }
universe@0: 
universe@0: char const* asc_get_error(void) {
universe@0:     // we zero-terminate the current buffer contents before providing them
universe@0:     cxBufferPut(&asc_context.error_buffer, 0);
universe@0:     --asc_context.error_buffer.pos;
universe@0:     --asc_context.error_buffer.size;
universe@0:     return asc_context.error_buffer.space;
universe@0: }
universe@0: 
universe@0: void asc_clear_error(void) {
universe@0:     cxBufferClear(&asc_context.error_buffer);
universe@0:     asc_clear_flag(&asc_context.flags, ASC_FLAG_HAS_ERROR);
universe@0: }
universe@0: 
universe@0: static void asc_event_window_resized(Uint32 id, Sint32 width, Sint32 height) {
universe@0:     CxIterator iter = cxListIterator(asc_context.windows);
universe@0:     cx_foreach(AscWindow*, w, iter) {
universe@0:         if (w->id == id) {
universe@0:             w->width = width;
universe@0:             w->height = height;
universe@0:             return;
universe@0:         }
universe@0:     }
universe@0: }
universe@0: 
universe@0: bool asc_loop_next(void) {
universe@0:     // dispatch SDL events
universe@0:     SDL_Event event;
universe@0:     while (SDL_PollEvent(&event)) {
universe@0:         switch (event.type) {
universe@0:         case SDL_QUIT:return false;
universe@0:         case SDL_WINDOWEVENT: {
universe@0:             if (event.window.type == SDL_WINDOWEVENT_RESIZED)
universe@0:                 asc_event_window_resized(
universe@0:                         event.window.windowID,
universe@0:                         event.window.data1,
universe@0:                         event.window.data2
universe@0:                 );
universe@0:             break;
universe@0:         }
universe@0:         case SDL_KEYDOWN:
universe@0:             // TODO: remove this code and implement key press map instead
universe@0:             if (event.key.keysym.sym == SDLK_ESCAPE)
universe@0:                 return false;
universe@0:             break;
universe@0:         case SDL_KEYUP:
universe@0:             // TODO: implement key press map
universe@0:             break;
universe@0:         }
universe@0:     }
universe@0: 
universe@0:     // sync the windows
universe@0:     CxMutIterator windows = cxListMutIterator(asc_context.windows);
universe@0:     cx_foreach(AscWindow*, w, windows) {
universe@0:         asc_window_sync(w);
universe@0:     }
universe@0:     return true;
universe@0: }
universe@0: 
universe@0: void asc_window_settings_init_defaults(AscWindowSettings* settings) {
universe@0:     settings->depth_size = 24;
universe@0:     settings->vsync = 1;
universe@0:     settings->width = 800;
universe@0:     settings->height = 600;
universe@0:     settings->fullscreen = 0;
universe@0:     settings->gl_major_version = 3;
universe@0:     settings->gl_minor_version = 3;
universe@0:     settings->title = "Ascended Window";
universe@0: }
universe@0: 
universe@0: void asc_window_initialize(AscWindow* window, AscWindowSettings const* settings) {
universe@0:     Uint32 flags = SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN;
universe@0:     flags |= settings->fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : SDL_WINDOW_RESIZABLE;
universe@0: 
universe@0:     window->window = SDL_CreateWindow(
universe@0:             settings->title,
universe@0:             SDL_WINDOWPOS_CENTERED,
universe@0:             SDL_WINDOWPOS_CENTERED,
universe@0:             settings->width,
universe@0:             settings->height,
universe@0:             flags
universe@0:     );
universe@0:     if (window->window == NULL) {
universe@0:         asc_error(SDL_GetError());
universe@0:         return;
universe@0:     }
universe@0: 
universe@0:     window->id = SDL_GetWindowID(window->window);
universe@0:     SDL_GetWindowSize(window->window, &window->width, &window->height);
universe@0: 
universe@0:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
universe@0:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, settings->gl_major_version);
universe@0:     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, settings->gl_minor_version);
universe@0:     SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, settings->depth_size);
universe@0:     SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
universe@0:     window->glctx = SDL_GL_CreateContext(window->window);
universe@0:     if (window->glctx == NULL) {
universe@0:         asc_dprintf("Creating GL context failed for window %u", window->id);
universe@0:     } else {
universe@0:         glewExperimental = GL_TRUE;
universe@0:         GLenum err = glewInit();
universe@0:         if (err == GLEW_OK) {
universe@0:             SDL_GL_SetSwapInterval(settings->vsync);
universe@0:             glEnable(GL_DEPTH_TEST);
universe@0:             glEnable(GL_BLEND);
universe@0:             glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
universe@0:             glEnable(GL_DEBUG_OUTPUT);
universe@0:             glDebugMessageCallback(asc_gl_debug_callback, NULL);
universe@0:             asc_dprintf("Window %u initialized", window->id);
universe@0:             cxListAdd(asc_context.windows, window);
universe@0:             return;
universe@0:         } else {
universe@0:             asc_error(glewGetErrorString(err));
universe@0:         }
universe@0:     }
universe@0: 
universe@0:     // cleanup on error
universe@0:     if (window->glctx != NULL) {
universe@0:         SDL_GL_DeleteContext(window->glctx);
universe@0:     }
universe@0:     window->glctx = NULL;
universe@0:     SDL_DestroyWindow(window->window);
universe@0:     window->window = NULL;
universe@0:     window->id = 0;
universe@0: }
universe@0: 
universe@0: void asc_window_destroy_impl(AscWindow* window) {
universe@0:     // destory the GL context and the window
universe@0:     if (window->glctx != NULL) {
universe@0:         SDL_GL_DeleteContext(window->glctx);
universe@0:     }
universe@0:     if (window->window != NULL) {
universe@0:         SDL_DestroyWindow(window->window);
universe@0:     }
universe@0: 
universe@0:     // clean the data
universe@0:     asc_dprintf("Window %u and its OpenGL context destroyed.", window->id);
universe@0:     memset(window, 0, sizeof(AscWindow));
universe@0: }
universe@0: 
universe@0: void asc_window_destroy(AscWindow* window) {
universe@0:     // find the window in the context and remove it
universe@2:     bool found = false;
universe@0:     CxMutIterator iter = cxListMutIterator(asc_context.windows);
universe@0:     cx_foreach(AscWindow*, w, iter) {
universe@0:         if (w == window) {
universe@2:             found = true;
universe@0:             cxIteratorFlagRemoval(iter);
universe@0:         }
universe@0:     }
universe@2:     if (!found) asc_window_destroy_impl(window);
universe@0: }
universe@0: 
universe@0: void asc_window_sync(AscWindow const* window) {
universe@0:     SDL_GL_MakeCurrent(window->window, window->glctx);
universe@0:     SDL_GL_SwapWindow(window->window);
universe@0:     glViewport(0, 0, window->width, window->height);
universe@0:     glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
universe@0:     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
universe@0: }