| //======================================================================== |
| // Vsync enabling test |
| // Copyright (c) Camilla Löwy <elmindreda@glfw.org> |
| // |
| // This software is provided 'as-is', without any express or implied |
| // warranty. In no event will the authors be held liable for any damages |
| // arising from the use of this software. |
| // |
| // Permission is granted to anyone to use this software for any purpose, |
| // including commercial applications, and to alter it and redistribute it |
| // freely, subject to the following restrictions: |
| // |
| // 1. The origin of this software must not be misrepresented; you must not |
| // claim that you wrote the original software. If you use this software |
| // in a product, an acknowledgment in the product documentation would |
| // be appreciated but is not required. |
| // |
| // 2. Altered source versions must be plainly marked as such, and must not |
| // be misrepresented as being the original software. |
| // |
| // 3. This notice may not be removed or altered from any source |
| // distribution. |
| // |
| //======================================================================== |
| // |
| // This test renders a high contrast, horizontally moving bar, allowing for |
| // visual verification of whether the set swap interval is indeed obeyed |
| // |
| //======================================================================== |
| |
| #include <glad/glad.h> |
| #include <GLFW/glfw3.h> |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <math.h> |
| |
| #include "getopt.h" |
| #include "linmath.h" |
| |
| static const struct |
| { |
| float x, y; |
| } vertices[4] = |
| { |
| { -0.25f, -1.f }, |
| { 0.25f, -1.f }, |
| { 0.25f, 1.f }, |
| { -0.25f, 1.f } |
| }; |
| |
| static const char* vertex_shader_text = |
| "#version 110\n" |
| "uniform mat4 MVP;\n" |
| "attribute vec2 vPos;\n" |
| "void main()\n" |
| "{\n" |
| " gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n" |
| "}\n"; |
| |
| static const char* fragment_shader_text = |
| "#version 110\n" |
| "void main()\n" |
| "{\n" |
| " gl_FragColor = vec4(1.0);\n" |
| "}\n"; |
| |
| static int swap_tear; |
| static int swap_interval; |
| static double frame_rate; |
| |
| static void usage(void) |
| { |
| printf("Usage: tearing [-f] [-h]\n"); |
| printf("Options:\n"); |
| printf(" -f use full screen\n"); |
| printf(" -h show this help\n"); |
| } |
| |
| static void update_window_title(GLFWwindow* window) |
| { |
| char title[256]; |
| |
| snprintf(title, sizeof(title), "Tearing detector (interval %i%s, %0.1f Hz)", |
| swap_interval, |
| (swap_tear && swap_interval < 0) ? " (swap tear)" : "", |
| frame_rate); |
| |
| glfwSetWindowTitle(window, title); |
| } |
| |
| static void set_swap_interval(GLFWwindow* window, int interval) |
| { |
| swap_interval = interval; |
| glfwSwapInterval(swap_interval); |
| update_window_title(window); |
| } |
| |
| static void error_callback(int error, const char* description) |
| { |
| fprintf(stderr, "Error: %s\n", description); |
| } |
| |
| static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) |
| { |
| if (action != GLFW_PRESS) |
| return; |
| |
| switch (key) |
| { |
| case GLFW_KEY_UP: |
| { |
| if (swap_interval + 1 > swap_interval) |
| set_swap_interval(window, swap_interval + 1); |
| break; |
| } |
| |
| case GLFW_KEY_DOWN: |
| { |
| if (swap_tear) |
| { |
| if (swap_interval - 1 < swap_interval) |
| set_swap_interval(window, swap_interval - 1); |
| } |
| else |
| { |
| if (swap_interval - 1 >= 0) |
| set_swap_interval(window, swap_interval - 1); |
| } |
| break; |
| } |
| |
| case GLFW_KEY_ESCAPE: |
| glfwSetWindowShouldClose(window, 1); |
| break; |
| |
| case GLFW_KEY_F11: |
| case GLFW_KEY_ENTER: |
| { |
| static int x, y, width, height; |
| |
| if (mods != GLFW_MOD_ALT) |
| return; |
| |
| if (glfwGetWindowMonitor(window)) |
| glfwSetWindowMonitor(window, NULL, x, y, width, height, 0); |
| else |
| { |
| GLFWmonitor* monitor = glfwGetPrimaryMonitor(); |
| const GLFWvidmode* mode = glfwGetVideoMode(monitor); |
| glfwGetWindowPos(window, &x, &y); |
| glfwGetWindowSize(window, &width, &height); |
| glfwSetWindowMonitor(window, monitor, |
| 0, 0, mode->width, mode->height, |
| mode->refreshRate); |
| } |
| |
| break; |
| } |
| } |
| } |
| |
| int main(int argc, char** argv) |
| { |
| unsigned long frame_count = 0; |
| GLFWmonitor* monitor = NULL; |
| int ch, width, height; |
| double last_time, current_time; |
| GLFWwindow* window; |
| GLuint vertex_buffer, vertex_shader, fragment_shader, program; |
| GLint mvp_location, vpos_location; |
| |
| glfwSetErrorCallback(error_callback); |
| |
| if (!glfwInit()) |
| exit(EXIT_FAILURE); |
| |
| while ((ch = getopt(argc, argv, "hf")) != -1) |
| { |
| switch (ch) |
| { |
| case 'h': |
| usage(); |
| exit(EXIT_SUCCESS); |
| |
| case 'f': |
| monitor = glfwGetPrimaryMonitor(); |
| break; |
| |
| default: |
| usage(); |
| exit(EXIT_FAILURE); |
| } |
| } |
| |
| if (monitor) |
| { |
| const GLFWvidmode* mode = glfwGetVideoMode(monitor); |
| |
| glfwWindowHint(GLFW_REFRESH_RATE, mode->refreshRate); |
| glfwWindowHint(GLFW_RED_BITS, mode->redBits); |
| glfwWindowHint(GLFW_GREEN_BITS, mode->greenBits); |
| glfwWindowHint(GLFW_BLUE_BITS, mode->blueBits); |
| |
| width = mode->width; |
| height = mode->height; |
| } |
| else |
| { |
| width = 640; |
| height = 480; |
| } |
| |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2); |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0); |
| |
| window = glfwCreateWindow(width, height, "Tearing detector", monitor, NULL); |
| if (!window) |
| { |
| glfwTerminate(); |
| exit(EXIT_FAILURE); |
| } |
| |
| glfwMakeContextCurrent(window); |
| gladLoadGLLoader((GLADloadproc) glfwGetProcAddress); |
| set_swap_interval(window, 0); |
| |
| last_time = glfwGetTime(); |
| frame_rate = 0.0; |
| swap_tear = (glfwExtensionSupported("WGL_EXT_swap_control_tear") || |
| glfwExtensionSupported("GLX_EXT_swap_control_tear")); |
| |
| glfwSetKeyCallback(window, key_callback); |
| |
| glGenBuffers(1, &vertex_buffer); |
| glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); |
| glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); |
| |
| vertex_shader = glCreateShader(GL_VERTEX_SHADER); |
| glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL); |
| glCompileShader(vertex_shader); |
| |
| fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); |
| glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL); |
| glCompileShader(fragment_shader); |
| |
| program = glCreateProgram(); |
| glAttachShader(program, vertex_shader); |
| glAttachShader(program, fragment_shader); |
| glLinkProgram(program); |
| |
| mvp_location = glGetUniformLocation(program, "MVP"); |
| vpos_location = glGetAttribLocation(program, "vPos"); |
| |
| glEnableVertexAttribArray(vpos_location); |
| glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE, |
| sizeof(vertices[0]), (void*) 0); |
| |
| while (!glfwWindowShouldClose(window)) |
| { |
| int width, height; |
| mat4x4 m, p, mvp; |
| float position = cosf((float) glfwGetTime() * 4.f) * 0.75f; |
| |
| glfwGetFramebufferSize(window, &width, &height); |
| |
| glViewport(0, 0, width, height); |
| glClear(GL_COLOR_BUFFER_BIT); |
| |
| mat4x4_ortho(p, -1.f, 1.f, -1.f, 1.f, 0.f, 1.f); |
| mat4x4_translate(m, position, 0.f, 0.f); |
| mat4x4_mul(mvp, p, m); |
| |
| glUseProgram(program); |
| glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp); |
| glDrawArrays(GL_TRIANGLE_FAN, 0, 4); |
| |
| glfwSwapBuffers(window); |
| glfwPollEvents(); |
| |
| frame_count++; |
| |
| current_time = glfwGetTime(); |
| if (current_time - last_time > 1.0) |
| { |
| frame_rate = frame_count / (current_time - last_time); |
| frame_count = 0; |
| last_time = current_time; |
| update_window_title(window); |
| } |
| } |
| |
| glfwTerminate(); |
| exit(EXIT_SUCCESS); |
| } |
| |