1 files changed, 275 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/src/camera/emscripten/SDL_camera_emscripten.c b/contrib/SDL-3.2.8/src/camera/emscripten/SDL_camera_emscripten.c
new file mode 100644
index 0000000..fa2a511
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/camera/emscripten/SDL_camera_emscripten.c
@@ -0,0 +1,275 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.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.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_CAMERA_DRIVER_EMSCRIPTEN
+
+#include "../SDL_syscamera.h"
+#include "../SDL_camera_c.h"
+#include "../../video/SDL_pixels_c.h"
+#include "../../video/SDL_surface_c.h"
+
+#include <emscripten/emscripten.h>
+
+// just turn off clang-format for this whole file, this INDENT_OFF stuff on
+//  each EM_ASM section is ugly.
+/* *INDENT-OFF* */ // clang-format off
+
+EM_JS_DEPS(sdlcamera, "$dynCall");
+
+static bool EMSCRIPTENCAMERA_WaitDevice(SDL_Camera *device)
+{
+    SDL_assert(!"This shouldn't be called");  // we aren't using SDL's internal thread.
+    return false;
+}
+
+static SDL_CameraFrameResult EMSCRIPTENCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+{
+    void *rgba = SDL_malloc(device->actual_spec.width * device->actual_spec.height * 4);
+    if (!rgba) {
+        return SDL_CAMERA_FRAME_ERROR;
+    }
+
+    *timestampNS = SDL_GetTicksNS();  // best we can do here.
+
+    const int rc = MAIN_THREAD_EM_ASM_INT({
+        const w = $0;
+        const h = $1;
+        const rgba = $2;
+        const SDL3 = Module['SDL3'];
+        if ((typeof(SDL3) === 'undefined') || (typeof(SDL3.camera) === 'undefined') || (typeof(SDL3.camera.ctx2d) === 'undefined')) {
+            return 0;  // don't have something we need, oh well.
+        }
+
+        SDL3.camera.ctx2d.drawImage(SDL3.camera.video, 0, 0, w, h);
+        const imgrgba = SDL3.camera.ctx2d.getImageData(0, 0, w, h).data;
+        Module.HEAPU8.set(imgrgba, rgba);
+
+        return 1;
+    }, device->actual_spec.width, device->actual_spec.height, rgba);
+
+    if (!rc) {
+        SDL_free(rgba);
+        return SDL_CAMERA_FRAME_ERROR;  // something went wrong, maybe shutting down; just don't return a frame.
+    }
+
+    frame->pixels = rgba;
+    frame->pitch = device->actual_spec.width * 4;
+
+    return SDL_CAMERA_FRAME_READY;
+}
+
+static void EMSCRIPTENCAMERA_ReleaseFrame(SDL_Camera *device, SDL_Surface *frame)
+{
+    SDL_free(frame->pixels);
+}
+
+static void EMSCRIPTENCAMERA_CloseDevice(SDL_Camera *device)
+{
+    if (device) {
+        MAIN_THREAD_EM_ASM({
+            const SDL3 = Module['SDL3'];
+            if ((typeof(SDL3) === 'undefined') || (typeof(SDL3.camera) === 'undefined') || (typeof(SDL3.camera.stream) === 'undefined')) {
+                return;  // camera was closed and/or subsystem was shut down, we're already done.
+            }
+            SDL3.camera.stream.getTracks().forEach(track => track.stop());  // stop all recording.
+            SDL3.camera = {};  // dump our references to everything.
+        });
+        SDL_free(device->hidden);
+        device->hidden = NULL;
+    }
+}
+
+static int SDLEmscriptenCameraPermissionOutcome(SDL_Camera *device, int approved, int w, int h, int fps)
+{
+    if (approved) {
+        device->actual_spec.format = SDL_PIXELFORMAT_RGBA32;
+        device->actual_spec.width = w;
+        device->actual_spec.height = h;
+        device->actual_spec.framerate_numerator = fps;
+        device->actual_spec.framerate_denominator = 1;
+
+        if (!SDL_PrepareCameraSurfaces(device)) {
+            // uhoh, we're in trouble. Probably ran out of memory.
+            SDL_LogError(SDL_LOG_CATEGORY_ERROR, "Camera could not prepare surfaces: %s ... revoking approval!", SDL_GetError());
+            approved = 0;  // disconnecting the SDL camera might not be safe here, just mark it as denied by user.
+        }
+    }
+
+    SDL_CameraPermissionOutcome(device, approved ? true : false);
+    return approved;
+}
+
+static bool EMSCRIPTENCAMERA_OpenDevice(SDL_Camera *device, const SDL_CameraSpec *spec)
+{
+    MAIN_THREAD_EM_ASM({
+        // Since we can't get actual specs until we make a move that prompts the user for
+        // permission, we don't list any specs for the device and wrangle it during device open.
+        const device = $0;
+        const w = $1;
+        const h = $2;
+        const framerate_numerator = $3;
+        const framerate_denominator = $4;
+        const outcome = $5;
+        const iterate = $6;
+
+        const constraints = {};
+        if ((w <= 0) || (h <= 0)) {
+            constraints.video = true;   // didn't ask for anything, let the system choose.
+        } else {
+            constraints.video = {};  // asked for a specific thing: request it as "ideal" but take closest hardware will offer.
+            constraints.video.width = w;
+            constraints.video.height = h;
+        }
+
+        if ((framerate_numerator > 0) && (framerate_denominator > 0)) {
+            var fps = framerate_numerator / framerate_denominator;
+            constraints.video.frameRate = { ideal: fps };
+        }
+
+        function grabNextCameraFrame() {  // !!! FIXME: this (currently) runs as a requestAnimationFrame callback, for lack of a better option.
+            const SDL3 = Module['SDL3'];
+            if ((typeof(SDL3) === 'undefined') || (typeof(SDL3.camera) === 'undefined') || (typeof(SDL3.camera.stream) === 'undefined')) {
+                return;  // camera was closed and/or subsystem was shut down, stop iterating here.
+            }
+
+            // time for a new frame from the camera?
+            const nextframems = SDL3.camera.next_frame_time;
+            const now = performance.now();
+            if (now >= nextframems) {
+                dynCall('vi', iterate, [device]);  // calls SDL_CameraThreadIterate, which will call our AcquireFrame implementation.
+
+                // bump ahead but try to stay consistent on timing, in case we dropped frames.
+                while (SDL3.camera.next_frame_time < now) {
+                    SDL3.camera.next_frame_time += SDL3.camera.fpsincrms;
+                }
+            }
+
+            requestAnimationFrame(grabNextCameraFrame);  // run this function again at the display framerate.  (!!! FIXME: would this be better as requestIdleCallback?)
+        }
+
+        navigator.mediaDevices.getUserMedia(constraints)
+            .then((stream) => {
+                const settings = stream.getVideoTracks()[0].getSettings();
+                const actualw = settings.width;
+                const actualh = settings.height;
+                const actualfps = settings.frameRate;
+                console.log("Camera is opened! Actual spec: (" + actualw + "x" + actualh + "), fps=" + actualfps);
+
+                if (dynCall('iiiiii', outcome, [device, 1, actualw, actualh, actualfps])) {
+                    const video = document.createElement("video");
+                    video.width = actualw;
+                    video.height = actualh;
+                    video.style.display = 'none';    // we need to attach this to a hidden video node so we can read it as pixels.
+                    video.srcObject = stream;
+
+                    const canvas = document.createElement("canvas");
+                    canvas.width = actualw;
+                    canvas.height = actualh;
+                    canvas.style.display = 'none';    // we need to attach this to a hidden video node so we can read it as pixels.
+
+                    const ctx2d = canvas.getContext('2d');
+
+                    const SDL3 = Module['SDL3'];
+                    SDL3.camera.width = actualw;
+                    SDL3.camera.height = actualh;
+                    SDL3.camera.fps = actualfps;
+                    SDL3.camera.fpsincrms = 1000.0 / actualfps;
+                    SDL3.camera.stream = stream;
+                    SDL3.camera.video = video;
+                    SDL3.camera.canvas = canvas;
+                    SDL3.camera.ctx2d = ctx2d;
+                    SDL3.camera.next_frame_time = performance.now();
+
+                    video.play();
+                    video.addEventListener('loadedmetadata', () => {
+                        grabNextCameraFrame();  // start this loop going.
+                    });
+                }
+            })
+            .catch((err) => {
+                console.error("Tried to open camera but it threw an error! " + err.name + ": " +  err.message);
+                dynCall('iiiiii', outcome, [device, 0, 0, 0, 0]);   // we call this a permission error, because it probably is.
+            });
+    }, device, spec->width, spec->height, spec->framerate_numerator, spec->framerate_denominator, SDLEmscriptenCameraPermissionOutcome, SDL_CameraThreadIterate);
+
+    return true;  // the real work waits until the user approves a camera.
+}
+
+static void EMSCRIPTENCAMERA_FreeDeviceHandle(SDL_Camera *device)
+{
+    // no-op.
+}
+
+static void EMSCRIPTENCAMERA_Deinitialize(void)
+{
+    MAIN_THREAD_EM_ASM({
+        if (typeof(Module['SDL3']) !== 'undefined') {
+            Module['SDL3'].camera = undefined;
+        }
+    });
+}
+
+static void EMSCRIPTENCAMERA_DetectDevices(void)
+{
+    // `navigator.mediaDevices` is not defined if unsupported or not in a secure context!
+    const int supported = MAIN_THREAD_EM_ASM_INT({ return (navigator.mediaDevices === undefined) ? 0 : 1; });
+
+    // if we have support at all, report a single generic camera with no specs.
+    //  We'll find out if there really _is_ a camera when we try to open it, but querying it for real here
+    //  will pop up a user permission dialog warning them we're trying to access the camera, and we generally
+    //  don't want that during SDL_Init().
+    if (supported) {
+        SDL_AddCamera("Web browser's camera", SDL_CAMERA_POSITION_UNKNOWN, 0, NULL, (void *) (size_t) 0x1);
+    }
+}
+
+static bool EMSCRIPTENCAMERA_Init(SDL_CameraDriverImpl *impl)
+{
+    MAIN_THREAD_EM_ASM({
+        if (typeof(Module['SDL3']) === 'undefined') {
+            Module['SDL3'] = {};
+        }
+        Module['SDL3'].camera = {};
+    });
+
+    impl->DetectDevices = EMSCRIPTENCAMERA_DetectDevices;
+    impl->OpenDevice = EMSCRIPTENCAMERA_OpenDevice;
+    impl->CloseDevice = EMSCRIPTENCAMERA_CloseDevice;
+    impl->WaitDevice = EMSCRIPTENCAMERA_WaitDevice;
+    impl->AcquireFrame = EMSCRIPTENCAMERA_AcquireFrame;
+    impl->ReleaseFrame = EMSCRIPTENCAMERA_ReleaseFrame;
+    impl->FreeDeviceHandle = EMSCRIPTENCAMERA_FreeDeviceHandle;
+    impl->Deinitialize = EMSCRIPTENCAMERA_Deinitialize;
+
+    impl->ProvidesOwnCallbackThread = true;
+
+    return true;
+}
+
+CameraBootStrap EMSCRIPTENCAMERA_bootstrap = {
+    "emscripten", "SDL Emscripten MediaStream camera driver", EMSCRIPTENCAMERA_Init, false
+};
+
+/* *INDENT-ON* */ // clang-format on
+
+#endif // SDL_CAMERA_DRIVER_EMSCRIPTEN
+