### fenster_pixel

Source: https://github.com/zserge/fenster/blob/main/README.md

Sets or gets a pixel color in the framebuffer. Can be used as an lvalue to set a pixel, or as an rvalue to get a pixel.

```APIDOC
## fenster_pixel

### Description
Sets or gets a pixel color in the framebuffer. Can be used as an lvalue to set a pixel, or as an rvalue to get a pixel.

### Method
C macro/function

### Signature
`fenster_pixel(f, x, y)`

### Parameters
- **f** (struct fenster*) - Required - Pointer to the fenster structure.
- **x** (int) - Required - X coordinate of the pixel.
- **y** (int) - Required - Y coordinate of the pixel.

### Return Value
- **uint32_t** - The pixel color in 24-bit RGB format (0xRRGGBB).

```

--------------------------------

### fenster_open

Source: https://github.com/zserge/fenster/blob/main/README.md

Opens a new application window with the specified title, dimensions, and framebuffer. Returns an integer status code.

```APIDOC
## fenster_open

### Description
Opens a new application window with the specified title, dimensions, and framebuffer. Returns an integer status code.

### Method
C function

### Signature
`int fenster_open(struct fenster *f)`

### Parameters
- **f** (struct fenster*) - Required - Pointer to the fenster structure containing window configuration (title, width, height, buffer).

### Return Value
- **int** - Status code (0 on success, non-zero on failure).

```

--------------------------------

### Draw white noise with Fenster

Source: https://github.com/zserge/fenster/blob/main/README.md

Creates a 320x240 window and fills it with random pixels in a polling loop. Compile with the platform-specific linker flags shown below.

```c
// main.c
#include "fenster.h"
#define W 320
#define H 240
int main() {
  uint32_t buf[W * H];
  struct fenster f = { .title = "hello", .width = W, .height = H, .buf = buf };
  fenster_open(&f);
  while (fenster_loop(&f) == 0) {
    for (int i = 0; i < W; i++) {
      for (int j = 0; j < H; j++) {
        fenster_pixel(&f, i, j) = rand();
      }
    }
  }
  fenster_close(&f);
  return 0;
}
```

```bash
# Linux
cc main.c -lX11 -lasound -o main && ./main
# macOS
cc main.c -framework Cocoa -framework AudioToolbox -o main && ./main
# windows
cc main.c -lgdi32 -lwinmm -o main.exe && main.exe
```

--------------------------------

### Fenster struct definition

Source: https://github.com/zserge/fenster/blob/main/README.md

Defines the main window structure with framebuffer, input state, and mouse data. Keys are mostly ASCII with arrows mapped to 17..20; mod is a 4-bit mask (ctrl=1, shift=2, alt=4, meta=8).

```c
struct fenster {
  const char *title; /* window title */
  const int width; /* window width */
  const int height; /* window height */
  uint32_t *buf; /* window pixels, 24-bit RGB, row by row, pixel by pixel */
  int keys[256]; /* keys are mostly ASCII, but arrows are 17..20 */
  int mod;       /* mod is 4 bits mask, ctrl=1, shift=2, alt=4, meta=8 */
  int x;         /* mouse X coordinate */
  int y;         /* mouse Y coordinate */
  int mouse;     /* 0 = no buttons pressed, 1 = left button pressed */
};
```

--------------------------------

### fenster_close

Source: https://github.com/zserge/fenster/blob/main/README.md

Closes the window and exits the graphical application.

```APIDOC
## fenster_close

### Description
Closes the window and exits the graphical application.

### Method
C function

### Signature
`void fenster_close(struct fenster *f)`

### Parameters
- **f** (struct fenster*) - Required - Pointer to the fenster structure.

### Return Value
None.

```

--------------------------------

### fenster_loop

Source: https://github.com/zserge/fenster/blob/main/README.md

Handles system events and refreshes the canvas. Returns a negative value when the application window is closed.

```APIDOC
## fenster_loop

### Description
Handles system events and refreshes the canvas. Returns a negative value when the application window is closed.

### Method
C function

### Signature
`int fenster_loop(struct fenster *f)`

### Parameters
- **f** (struct fenster*) - Required - Pointer to the fenster structure.

### Return Value
- **int** - 0 if the loop should continue, negative if the window is closed.

```

--------------------------------

### fenster_time

Source: https://github.com/zserge/fenster/blob/main/README.md

Returns the current time in milliseconds.

```APIDOC
## fenster_time

### Description
Returns the current time in milliseconds.

### Method
C function

### Signature
`int64_t fenster_time()`

### Parameters
None.

### Return Value
- **int64_t** - Current time in milliseconds.

```

--------------------------------

### fenster_sleep

Source: https://github.com/zserge/fenster/blob/main/README.md

Pauses execution for a specified number of milliseconds.

```APIDOC
## fenster_sleep

### Description
Pauses execution for a specified number of milliseconds.

### Method
C function

### Signature
`void fenster_sleep(int ms)`

### Parameters
- **ms** (int) - Required - Number of milliseconds to pause.

### Return Value
None.

```

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