| //======================================================================== |
| // Cursor animation |
| // Copyright (c) Camilla Berglund <elmindreda@elmindreda.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. |
| // |
| //======================================================================== |
| // |
| // Cursor animation test. |
| // |
| //======================================================================== |
| |
| #include <GLFW/glfw3.h> |
| |
| #include <stdlib.h> |
| #include <math.h> |
| |
| #ifdef min |
| #undef min |
| #endif |
| #ifdef max |
| #undef max |
| #endif |
| |
| #define SIZE 64 // cursor size (width & height) |
| #define N 60 // number of frames |
| |
| unsigned char buffer[4 * SIZE * SIZE]; |
| |
| static float max(float a, float b) { return a > b ? a : b; } |
| static float min(float a, float b) { return a < b ? a : b; } |
| |
| static float star(int x, int y, float t) |
| { |
| float c = SIZE / 2.0f; |
| |
| float i = (0.25f * (float)sin(2.0f * 3.1415926f * t) + 0.75f); |
| float k = SIZE * 0.046875f * i; |
| |
| float dist = (float)sqrt((x - c) * (x - c) + (y - c) * (y - c)); |
| |
| float salpha = 1.0f - dist / c; |
| float xalpha = (float)x == c ? c : k / (float)fabs(x - c); |
| float yalpha = (float)y == c ? c : k / (float)fabs(y - c); |
| |
| return max(0.0f, min(1.0f, i * salpha * 0.2f + salpha * xalpha * yalpha)); |
| } |
| |
| static GLFWcursor* load_frame(float t) |
| { |
| int i = 0, x, y; |
| const GLFWimage image = { SIZE, SIZE, buffer }; |
| |
| for (y = 0; y < image.width; y++) |
| { |
| for (x = 0; x < image.height; x++) |
| { |
| buffer[i++] = 255; |
| buffer[i++] = 255; |
| buffer[i++] = 255; |
| buffer[i++] = (unsigned char)(255 * star(x, y, t)); |
| } |
| } |
| |
| return glfwCreateCursor(&image, image.width / 2, image.height / 2); |
| } |
| |
| int main(void) |
| { |
| int i; |
| double t0, t1, frameTime = 0.0; |
| |
| GLFWwindow* window; |
| GLFWcursor* frames[N]; |
| |
| if (!glfwInit()) |
| exit(EXIT_FAILURE); |
| |
| window = glfwCreateWindow(640, 480, "Cursor animation", NULL, NULL); |
| |
| if (!window) |
| { |
| glfwTerminate(); |
| exit(EXIT_FAILURE); |
| } |
| |
| glfwMakeContextCurrent(window); |
| glfwSwapInterval(1); |
| |
| for (i = 0; i < N; i++) |
| frames[i] = load_frame(i / (float)N); |
| |
| i = 0; |
| |
| t0 = glfwGetTime(); |
| |
| while (!glfwWindowShouldClose(window)) |
| { |
| glClear(GL_COLOR_BUFFER_BIT); |
| glfwSetCursor(window, frames[i]); |
| glfwSwapBuffers(window); |
| glfwPollEvents(); |
| |
| t1 = glfwGetTime(); |
| frameTime += t1 - t0; |
| t0 = t1; |
| |
| while (frameTime > 1.0 / (double)N) |
| { |
| i = (i + 1) % N; |
| frameTime -= 1.0 / (double)N; |
| } |
| } |
| |
| glfwTerminate(); |
| exit(EXIT_SUCCESS); |
| } |
| |