diff options
Diffstat (limited to 'examples/pugl_shader_demo.c')
| -rw-r--r-- | examples/pugl_shader_demo.c | 702 |
1 files changed, 343 insertions, 359 deletions
diff --git a/examples/pugl_shader_demo.c b/examples/pugl_shader_demo.c index 8ebbe60..d038b3f 100644 --- a/examples/pugl_shader_demo.c +++ b/examples/pugl_shader_demo.c @@ -56,30 +56,28 @@ static const int defaultWidth = 512; static const int defaultHeight = 512; static const uintptr_t resizeTimerId = 1u; -typedef struct -{ - mat4 projection; +typedef struct { + mat4 projection; } RectUniforms; -typedef struct -{ - const char* programPath; - PuglWorld* world; - PuglView* view; - PuglTestOptions opts; - size_t numRects; - Rect* rects; - Program drawRect; - GLuint vao; - GLuint vbo; - GLuint instanceVbo; - GLuint ibo; - double lastDrawDuration; - double lastFrameEndTime; - unsigned framesDrawn; - int glMajorVersion; - int glMinorVersion; - int quit; +typedef struct { + const char* programPath; + PuglWorld* world; + PuglView* view; + PuglTestOptions opts; + size_t numRects; + Rect* rects; + Program drawRect; + GLuint vao; + GLuint vbo; + GLuint instanceVbo; + GLuint ibo; + double lastDrawDuration; + double lastFrameEndTime; + unsigned framesDrawn; + int glMajorVersion; + int glMinorVersion; + int quit; } PuglTestApp; static PuglStatus @@ -91,393 +89,379 @@ teardownGl(PuglTestApp* app); static void onConfigure(PuglView* view, double width, double height) { - (void)view; + (void)view; - glEnable(GL_BLEND); - glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO); - glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD); - glClearColor(0.0f, 0.0f, 0.0f, 1.0f); - glViewport(0, 0, (int)width, (int)height); + glEnable(GL_BLEND); + glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO); + glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD); + glClearColor(0.0f, 0.0f, 0.0f, 1.0f); + glViewport(0, 0, (int)width, (int)height); } static void onExpose(PuglView* view) { - PuglTestApp* app = (PuglTestApp*)puglGetHandle(view); - const PuglRect frame = puglGetFrame(view); - const float width = (float)frame.width; - const float height = (float)frame.height; - const double time = puglGetTime(puglGetWorld(view)); - - // Construct projection matrix for 2D window surface (in pixels) - mat4 proj; - mat4Ortho(proj, - 0.0f, - (float)frame.width, - 0.0f, - (float)frame.height, - -1.0f, - 1.0f); - - // Clear and bind everything that is the same for every rect - glClear(GL_COLOR_BUFFER_BIT); - glUseProgram(app->drawRect.program); - glBindVertexArray(app->vao); - - for (size_t i = 0; i < app->numRects; ++i) { - moveRect(&app->rects[i], i, app->numRects, width, height, time); - } - - glBufferData(GL_UNIFORM_BUFFER, sizeof(proj), &proj, GL_STREAM_DRAW); - - glBufferSubData(GL_ARRAY_BUFFER, - 0, - (GLsizeiptr)(app->numRects * sizeof(Rect)), - app->rects); - - glDrawElementsInstanced(GL_TRIANGLE_STRIP, - 4, - GL_UNSIGNED_INT, - NULL, - (GLsizei)(app->numRects * 4)); - - ++app->framesDrawn; - - app->lastFrameEndTime = puglGetTime(puglGetWorld(view)); - app->lastDrawDuration = app->lastFrameEndTime - time; + PuglTestApp* app = (PuglTestApp*)puglGetHandle(view); + const PuglRect frame = puglGetFrame(view); + const float width = (float)frame.width; + const float height = (float)frame.height; + const double time = puglGetTime(puglGetWorld(view)); + + // Construct projection matrix for 2D window surface (in pixels) + mat4 proj; + mat4Ortho( + proj, 0.0f, (float)frame.width, 0.0f, (float)frame.height, -1.0f, 1.0f); + + // Clear and bind everything that is the same for every rect + glClear(GL_COLOR_BUFFER_BIT); + glUseProgram(app->drawRect.program); + glBindVertexArray(app->vao); + + for (size_t i = 0; i < app->numRects; ++i) { + moveRect(&app->rects[i], i, app->numRects, width, height, time); + } + + glBufferData(GL_UNIFORM_BUFFER, sizeof(proj), &proj, GL_STREAM_DRAW); + + glBufferSubData( + GL_ARRAY_BUFFER, 0, (GLsizeiptr)(app->numRects * sizeof(Rect)), app->rects); + + glDrawElementsInstanced( + GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_INT, NULL, (GLsizei)(app->numRects * 4)); + + ++app->framesDrawn; + + app->lastFrameEndTime = puglGetTime(puglGetWorld(view)); + app->lastDrawDuration = app->lastFrameEndTime - time; } static PuglStatus onEvent(PuglView* view, const PuglEvent* event) { - PuglTestApp* app = (PuglTestApp*)puglGetHandle(view); - - printEvent(event, "Event: ", app->opts.verbose); - - switch (event->type) { - case PUGL_CREATE: - setupGl(app); - break; - case PUGL_DESTROY: - teardownGl(app); - break; - case PUGL_CONFIGURE: - onConfigure(view, event->configure.width, event->configure.height); - break; - case PUGL_UPDATE: - puglPostRedisplay(view); - break; - case PUGL_EXPOSE: onExpose(view); break; - case PUGL_CLOSE: app->quit = 1; break; - case PUGL_LOOP_ENTER: - puglStartTimer(view, - resizeTimerId, - 1.0 / (double)puglGetViewHint(view, PUGL_REFRESH_RATE)); - break; - case PUGL_LOOP_LEAVE: - puglStopTimer(view, resizeTimerId); - break; - case PUGL_KEY_PRESS: - if (event->key.key == 'q' || event->key.key == PUGL_KEY_ESCAPE) { - app->quit = 1; - } - break; - case PUGL_TIMER: - if (event->timer.id == resizeTimerId) { - puglPostRedisplay(view); - } - break; - default: break; - } - - return PUGL_SUCCESS; + PuglTestApp* app = (PuglTestApp*)puglGetHandle(view); + + printEvent(event, "Event: ", app->opts.verbose); + + switch (event->type) { + case PUGL_CREATE: + setupGl(app); + break; + case PUGL_DESTROY: + teardownGl(app); + break; + case PUGL_CONFIGURE: + onConfigure(view, event->configure.width, event->configure.height); + break; + case PUGL_UPDATE: + puglPostRedisplay(view); + break; + case PUGL_EXPOSE: + onExpose(view); + break; + case PUGL_CLOSE: + app->quit = 1; + break; + case PUGL_LOOP_ENTER: + puglStartTimer(view, + resizeTimerId, + 1.0 / (double)puglGetViewHint(view, PUGL_REFRESH_RATE)); + break; + case PUGL_LOOP_LEAVE: + puglStopTimer(view, resizeTimerId); + break; + case PUGL_KEY_PRESS: + if (event->key.key == 'q' || event->key.key == PUGL_KEY_ESCAPE) { + app->quit = 1; + } + break; + case PUGL_TIMER: + if (event->timer.id == resizeTimerId) { + puglPostRedisplay(view); + } + break; + default: + break; + } + + return PUGL_SUCCESS; } static Rect* makeRects(const size_t numRects) { - Rect* rects = (Rect*)calloc(numRects, sizeof(Rect)); - for (size_t i = 0; i < numRects; ++i) { - rects[i] = makeRect(i, (float)defaultWidth); - } + Rect* rects = (Rect*)calloc(numRects, sizeof(Rect)); + for (size_t i = 0; i < numRects; ++i) { + rects[i] = makeRect(i, (float)defaultWidth); + } - return rects; + return rects; } static char* loadShader(const char* const programPath, const char* const name) { - char* const path = resourcePath(programPath, name); - fprintf(stderr, "Loading shader %s\n", path); + char* const path = resourcePath(programPath, name); + fprintf(stderr, "Loading shader %s\n", path); - FILE* const file = fopen(path, "r"); - if (!file) { - logError("Failed to open '%s'\n", path); - return NULL; - } + FILE* const file = fopen(path, "r"); + if (!file) { + logError("Failed to open '%s'\n", path); + return NULL; + } - free(path); - fseek(file, 0, SEEK_END); - const size_t fileSize = (size_t)ftell(file); + free(path); + fseek(file, 0, SEEK_END); + const size_t fileSize = (size_t)ftell(file); - fseek(file, 0, SEEK_SET); - char* source = (char*)calloc(1, fileSize + 1u); + fseek(file, 0, SEEK_SET); + char* source = (char*)calloc(1, fileSize + 1u); - fread(source, 1, fileSize, file); - fclose(file); + fread(source, 1, fileSize, file); + fclose(file); - return source; + return source; } static int parseOptions(PuglTestApp* app, int argc, char** argv) { - char* endptr = NULL; - - // Parse command line options - app->numRects = 1024; - app->opts = puglParseTestOptions(&argc, &argv); - if (app->opts.help) { - return 1; - } - - // Parse number of rectangles argument, if given - if (argc >= 1) { - app->numRects = (size_t)strtol(argv[0], &endptr, 10); - if (endptr != argv[0] + strlen(argv[0])) { - logError("Invalid number of rectangles: %s\n", argv[0]); - return 1; - } - } - - // Parse OpenGL major version argument, if given - if (argc >= 2) { - app->glMajorVersion = (int)strtol(argv[1], &endptr, 10); - if (endptr != argv[1] + strlen(argv[1])) { - logError("Invalid GL major version: %s\n", argv[1]); - return 1; - } else if (app->glMajorVersion == 4) { - app->glMinorVersion = 2; - } else if (app->glMajorVersion != 3) { - logError("Unsupported GL major version %d\n", app->glMajorVersion); - return 1; - } - } - - return 0; + char* endptr = NULL; + + // Parse command line options + app->numRects = 1024; + app->opts = puglParseTestOptions(&argc, &argv); + if (app->opts.help) { + return 1; + } + + // Parse number of rectangles argument, if given + if (argc >= 1) { + app->numRects = (size_t)strtol(argv[0], &endptr, 10); + if (endptr != argv[0] + strlen(argv[0])) { + logError("Invalid number of rectangles: %s\n", argv[0]); + return 1; + } + } + + // Parse OpenGL major version argument, if given + if (argc >= 2) { + app->glMajorVersion = (int)strtol(argv[1], &endptr, 10); + if (endptr != argv[1] + strlen(argv[1])) { + logError("Invalid GL major version: %s\n", argv[1]); + return 1; + } else if (app->glMajorVersion == 4) { + app->glMinorVersion = 2; + } else if (app->glMajorVersion != 3) { + logError("Unsupported GL major version %d\n", app->glMajorVersion); + return 1; + } + } + + return 0; } static void setupPugl(PuglTestApp* app) { - // Create world, view, and rect data - app->world = puglNewWorld(PUGL_PROGRAM, 0); - app->view = puglNewView(app->world); - app->rects = makeRects(app->numRects); - - // Set up world and view - puglSetClassName(app->world, "PuglGL3Demo"); - puglSetWindowTitle(app->view, "Pugl OpenGL 3"); - puglSetDefaultSize(app->view, defaultWidth, defaultHeight); - puglSetMinSize(app->view, defaultWidth / 4, defaultHeight / 4); - puglSetAspectRatio(app->view, 1, 1, 16, 9); - puglSetBackend(app->view, puglGlBackend()); - puglSetViewHint(app->view, PUGL_USE_COMPAT_PROFILE, PUGL_FALSE); - puglSetViewHint(app->view, PUGL_USE_DEBUG_CONTEXT, app->opts.errorChecking); - puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MAJOR, app->glMajorVersion); - puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MINOR, app->glMinorVersion); - puglSetViewHint(app->view, PUGL_RESIZABLE, app->opts.resizable); - puglSetViewHint(app->view, PUGL_SAMPLES, app->opts.samples); - puglSetViewHint(app->view, PUGL_DOUBLE_BUFFER, app->opts.doubleBuffer); - puglSetViewHint(app->view, PUGL_SWAP_INTERVAL, app->opts.sync); - puglSetViewHint(app->view, PUGL_IGNORE_KEY_REPEAT, PUGL_TRUE); - puglSetHandle(app->view, app); - puglSetEventFunc(app->view, onEvent); + // Create world, view, and rect data + app->world = puglNewWorld(PUGL_PROGRAM, 0); + app->view = puglNewView(app->world); + app->rects = makeRects(app->numRects); + + // Set up world and view + puglSetClassName(app->world, "PuglGL3Demo"); + puglSetWindowTitle(app->view, "Pugl OpenGL 3"); + puglSetDefaultSize(app->view, defaultWidth, defaultHeight); + puglSetMinSize(app->view, defaultWidth / 4, defaultHeight / 4); + puglSetAspectRatio(app->view, 1, 1, 16, 9); + puglSetBackend(app->view, puglGlBackend()); + puglSetViewHint(app->view, PUGL_USE_COMPAT_PROFILE, PUGL_FALSE); + puglSetViewHint(app->view, PUGL_USE_DEBUG_CONTEXT, app->opts.errorChecking); + puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MAJOR, app->glMajorVersion); + puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MINOR, app->glMinorVersion); + puglSetViewHint(app->view, PUGL_RESIZABLE, app->opts.resizable); + puglSetViewHint(app->view, PUGL_SAMPLES, app->opts.samples); + puglSetViewHint(app->view, PUGL_DOUBLE_BUFFER, app->opts.doubleBuffer); + puglSetViewHint(app->view, PUGL_SWAP_INTERVAL, app->opts.sync); + puglSetViewHint(app->view, PUGL_IGNORE_KEY_REPEAT, PUGL_TRUE); + puglSetHandle(app->view, app); + puglSetEventFunc(app->view, onEvent); } static PuglStatus setupGl(PuglTestApp* app) { - // Load GL functions via GLAD - if (!gladLoadGLLoader((GLADloadproc)&puglGetProcAddress)) { - logError("Failed to load GL\n"); - return PUGL_FAILURE; - } - - const char* const headerFile = (app->glMajorVersion == 3 - ? "shaders/header_330.glsl" - : "shaders/header_420.glsl"); - - // Load shader sources - char* const headerSource = loadShader(app->programPath, headerFile); - - char* const vertexSource = loadShader(app->programPath, - "shaders/rect.vert"); - - char* const fragmentSource = loadShader(app->programPath, - "shaders/rect.frag"); - - if (!vertexSource || !fragmentSource) { - logError("Failed to load shader sources\n"); - return PUGL_FAILURE; - } - - // Compile rectangle shaders and program - app->drawRect = compileProgram(headerSource, vertexSource, fragmentSource); - free(fragmentSource); - free(vertexSource); - free(headerSource); - if (!app->drawRect.program) { - return PUGL_FAILURE; - } - - // Get location of rectangle shader uniform block - const GLuint globalsIndex = glGetUniformBlockIndex(app->drawRect.program, - "UniformBufferObject"); - - // Generate/bind a uniform buffer for setting rectangle properties - GLuint uboHandle = 0; - glGenBuffers(1, &uboHandle); - glBindBuffer(GL_UNIFORM_BUFFER, uboHandle); - glBindBufferBase(GL_UNIFORM_BUFFER, globalsIndex, uboHandle); - - // Generate/bind a VAO to track state - glGenVertexArrays(1, &app->vao); - glBindVertexArray(app->vao); - - // Generate/bind a VBO to store vertex position data - glGenBuffers(1, &app->vbo); - glBindBuffer(GL_ARRAY_BUFFER, app->vbo); - glBufferData(GL_ARRAY_BUFFER, - sizeof(rectVertices), - rectVertices, - GL_STATIC_DRAW); - - // Attribute 0 is position, 2 floats from the VBO - glEnableVertexAttribArray(0); - glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), NULL); - - // Generate/bind a VBO to store instance attribute data - glGenBuffers(1, &app->instanceVbo); - glBindBuffer(GL_ARRAY_BUFFER, app->instanceVbo); - glBufferData(GL_ARRAY_BUFFER, - (GLsizeiptr)(app->numRects * sizeof(Rect)), - app->rects, - GL_STREAM_DRAW); - - // Attribute 1 is Rect::position - glEnableVertexAttribArray(1); - glVertexAttribDivisor(1, 4); - glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Rect), NULL); - - // Attribute 2 is Rect::size - glEnableVertexAttribArray(2); - glVertexAttribDivisor(2, 4); - glVertexAttribPointer(2, - 2, - GL_FLOAT, - GL_FALSE, - sizeof(Rect), - (const void*)offsetof(Rect, size)); - - // Attribute 3 is Rect::fillColor - glEnableVertexAttribArray(3); - glVertexAttribDivisor(3, 4); - glVertexAttribPointer(3, - 4, - GL_FLOAT, - GL_FALSE, - sizeof(Rect), - (const void*)offsetof(Rect, fillColor)); - - // Set up the IBO to index into the VBO - glGenBuffers(1, &app->ibo); - glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, app->ibo); - glBufferData(GL_ELEMENT_ARRAY_BUFFER, - sizeof(rectIndices), - rectIndices, - GL_STATIC_DRAW); - - return PUGL_SUCCESS; + // Load GL functions via GLAD + if (!gladLoadGLLoader((GLADloadproc)&puglGetProcAddress)) { + logError("Failed to load GL\n"); + return PUGL_FAILURE; + } + + const char* const headerFile = + (app->glMajorVersion == 3 ? "shaders/header_330.glsl" + : "shaders/header_420.glsl"); + + // Load shader sources + char* const headerSource = loadShader(app->programPath, headerFile); + + char* const vertexSource = loadShader(app->programPath, "shaders/rect.vert"); + + char* const fragmentSource = + loadShader(app->programPath, "shaders/rect.frag"); + + if (!vertexSource || !fragmentSource) { + logError("Failed to load shader sources\n"); + return PUGL_FAILURE; + } + + // Compile rectangle shaders and program + app->drawRect = compileProgram(headerSource, vertexSource, fragmentSource); + free(fragmentSource); + free(vertexSource); + free(headerSource); + if (!app->drawRect.program) { + return PUGL_FAILURE; + } + + // Get location of rectangle shader uniform block + const GLuint globalsIndex = + glGetUniformBlockIndex(app->drawRect.program, "UniformBufferObject"); + + // Generate/bind a uniform buffer for setting rectangle properties + GLuint uboHandle = 0; + glGenBuffers(1, &uboHandle); + glBindBuffer(GL_UNIFORM_BUFFER, uboHandle); + glBindBufferBase(GL_UNIFORM_BUFFER, globalsIndex, uboHandle); + + // Generate/bind a VAO to track state + glGenVertexArrays(1, &app->vao); + glBindVertexArray(app->vao); + + // Generate/bind a VBO to store vertex position data + glGenBuffers(1, &app->vbo); + glBindBuffer(GL_ARRAY_BUFFER, app->vbo); + glBufferData( + GL_ARRAY_BUFFER, sizeof(rectVertices), rectVertices, GL_STATIC_DRAW); + + // Attribute 0 is position, 2 floats from the VBO + glEnableVertexAttribArray(0); + glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat), NULL); + + // Generate/bind a VBO to store instance attribute data + glGenBuffers(1, &app->instanceVbo); + glBindBuffer(GL_ARRAY_BUFFER, app->instanceVbo); + glBufferData(GL_ARRAY_BUFFER, + (GLsizeiptr)(app->numRects * sizeof(Rect)), + app->rects, + GL_STREAM_DRAW); + + // Attribute 1 is Rect::position + glEnableVertexAttribArray(1); + glVertexAttribDivisor(1, 4); + glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Rect), NULL); + + // Attribute 2 is Rect::size + glEnableVertexAttribArray(2); + glVertexAttribDivisor(2, 4); + glVertexAttribPointer( + 2, 2, GL_FLOAT, GL_FALSE, sizeof(Rect), (const void*)offsetof(Rect, size)); + + // Attribute 3 is Rect::fillColor + glEnableVertexAttribArray(3); + glVertexAttribDivisor(3, 4); + glVertexAttribPointer(3, + 4, + GL_FLOAT, + GL_FALSE, + sizeof(Rect), + (const void*)offsetof(Rect, fillColor)); + + // Set up the IBO to index into the VBO + glGenBuffers(1, &app->ibo); + glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, app->ibo); + glBufferData( + GL_ELEMENT_ARRAY_BUFFER, sizeof(rectIndices), rectIndices, GL_STATIC_DRAW); + + return PUGL_SUCCESS; } static void teardownGl(PuglTestApp* app) { - glDeleteBuffers(1, &app->ibo); - glDeleteBuffers(1, &app->vbo); - glDeleteBuffers(1, &app->instanceVbo); - glDeleteVertexArrays(1, &app->vao); - deleteProgram(app->drawRect); + glDeleteBuffers(1, &app->ibo); + glDeleteBuffers(1, &app->vbo); + glDeleteBuffers(1, &app->instanceVbo); + glDeleteVertexArrays(1, &app->vao); + deleteProgram(app->drawRect); } int main(int argc, char** argv) { - PuglTestApp app = {0}; - - app.programPath = argv[0]; - app.glMajorVersion = 3; - app.glMinorVersion = 3; - - // Parse command line options - if (parseOptions(&app, argc, argv)) { - puglPrintTestUsage("pugl_shader_demo", "[NUM_RECTS] [GL_MAJOR]"); - return 1; - } - - // Create and configure world and view - setupPugl(&app); - - // Create window (which will send a PUGL_CREATE event) - const PuglStatus st = puglRealize(app.view); - if (st) { - return logError("Failed to create window (%s)\n", puglStrerror(st)); - } - - // Show window - printViewHints(app.view); - puglShow(app.view); - - // Calculate ideal frame duration to drive the main loop at a good rate - const int refreshRate = puglGetViewHint(app.view, PUGL_REFRESH_RATE); - const double frameDuration = 1.0 / (double)refreshRate; - - // Grind away, drawing continuously - const double startTime = puglGetTime(app.world); - PuglFpsPrinter fpsPrinter = {startTime}; - while (!app.quit) { - /* To minimize input latency and get smooth performance during window - resizing, we want to poll for events as long as possible before - starting to draw the next frame. This ensures that as many events - are consumed as possible before starting to draw, or, equivalently, - that the next rendered frame represents the latest events possible. - This is particularly important for mouse input and "live" window - resizing, where many events tend to pile up within a frame. - - To do this, we keep track of the time when the last frame was - finished drawing, and how long it took to expose (and assume this is - relatively stable). Then, we can calculate how much time there is - from now until the time when we should start drawing to not miss the - deadline, and use that as the timeout for puglUpdate(). - */ - - const double now = puglGetTime(app.world); - const double nextFrameEndTime = app.lastFrameEndTime + frameDuration; - const double nextExposeTime = nextFrameEndTime - app.lastDrawDuration; - const double timeUntilNext = nextExposeTime - now; - const double timeout = app.opts.sync ? timeUntilNext : 0.0; - - puglUpdate(app.world, fmax(0.0, timeout)); - puglPrintFps(app.world, &fpsPrinter, &app.framesDrawn); - } - - // Destroy window (which will send a PUGL_DESTROY event) - puglFreeView(app.view); - - // Free everything else - puglFreeWorld(app.world); - free(app.rects); - - return 0; + PuglTestApp app = {0}; + + app.programPath = argv[0]; + app.glMajorVersion = 3; + app.glMinorVersion = 3; + + // Parse command line options + if (parseOptions(&app, argc, argv)) { + puglPrintTestUsage("pugl_shader_demo", "[NUM_RECTS] [GL_MAJOR]"); + return 1; + } + + // Create and configure world and view + setupPugl(&app); + + // Create window (which will send a PUGL_CREATE event) + const PuglStatus st = puglRealize(app.view); + if (st) { + return logError("Failed to create window (%s)\n", puglStrerror(st)); + } + + // Show window + printViewHints(app.view); + puglShow(app.view); + + // Calculate ideal frame duration to drive the main loop at a good rate + const int refreshRate = puglGetViewHint(app.view, PUGL_REFRESH_RATE); + const double frameDuration = 1.0 / (double)refreshRate; + + // Grind away, drawing continuously + const double startTime = puglGetTime(app.world); + PuglFpsPrinter fpsPrinter = {startTime}; + while (!app.quit) { + /* To minimize input latency and get smooth performance during window + resizing, we want to poll for events as long as possible before + starting to draw the next frame. This ensures that as many events + are consumed as possible before starting to draw, or, equivalently, + that the next rendered frame represents the latest events possible. + This is particularly important for mouse input and "live" window + resizing, where many events tend to pile up within a frame. + + To do this, we keep track of the time when the last frame was + finished drawing, and how long it took to expose (and assume this is + relatively stable). Then, we can calculate how much time there is + from now until the time when we should start drawing to not miss the + deadline, and use that as the timeout for puglUpdate(). + */ + + const double now = puglGetTime(app.world); + const double nextFrameEndTime = app.lastFrameEndTime + frameDuration; + const double nextExposeTime = nextFrameEndTime - app.lastDrawDuration; + const double timeUntilNext = nextExposeTime - now; + const double timeout = app.opts.sync ? timeUntilNext : 0.0; + + puglUpdate(app.world, fmax(0.0, timeout)); + puglPrintFps(app.world, &fpsPrinter, &app.framesDrawn); + } + + // Destroy window (which will send a PUGL_DESTROY event) + puglFreeView(app.view); + + // Free everything else + puglFreeWorld(app.world); + free(app.rects); + + return 0; } |