136 lines
3.4 KiB
C
136 lines
3.4 KiB
C
//========================================================================
|
|
// 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);
|
|
}
|
|
|