1 files changed, 144 insertions, 0 deletions
diff --git a/state.c b/state.c
new file mode 100644
index 0000000..4e7b00d
--- /dev/null
+++ b/state.c
@@ -0,0 +1,144 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+/**
+ * The framebuffers on the system
+ */
+framebuffer_t *restrict framebuffers = NULL;
+
+/**
+ * The number of elements in `framebuffers`
+ */
+size_t framebuffer_count = 0;
+
+/**
+ * The graphics cards on the system
+ */
+drm_card_t *restrict cards = NULL;
+
+/**
+ * The number of elements in `cards`
+ */
+size_t card_count = 0;
+
+/**
+ * The connected CRT controllers on the system
+ */
+drm_crtc_t *restrict crtcs = NULL;
+
+/**
+ * The software brightness setting on each connected CRT controller, on each channel
+ */
+double *restrict brightnesses[3];
+
+/**
+ * The software contrast setting on each connected CRT controller, on each channel
+ */
+double *restrict contrasts[3];
+
+/**
+ * The gamma correction on each connected CRT controller, on each channel
+ */
+double *restrict gammas[3];
+
+/**
+ * The number of elements in `crtcs`, `brightnesses[]`, `contrasts[]` and `gammas[]`
+ */
+size_t crtc_count = 0;
+
+
+
+/**
+ * Acquire video control
+ * 
+ * @return  Zero on success, -1 on error
+ */
+int
+acquire_video(void)
+{
+	size_t f, c, i, fn = fb_count(), cn = drm_card_count();
+	drm_crtc_t *restrict old_crtcs, crtc;
+	drm_card_t card;
+	framebuffer_t fb;
+
+	framebuffers = malloc(fn * sizeof(framebuffer_t));
+	if (!framebuffers)
+		return -1;
+
+	for (f = 0; f < fn; f++) {
+		if (fb_open(f, &fb) < 0)
+			return -1;
+		framebuffers[framebuffer_count++] = fb;
+	}
+
+	cards = malloc(cn * sizeof(drm_card_t));
+	if (!cards)
+		return -1;
+
+	for (c = 0; c < cn; c++) {
+		if (drm_card_open(c, &card) < 0)
+			return -1;
+		cards[card_count++] = card;
+
+		old_crtcs = crtcs;
+		crtcs = realloc(crtcs, (crtc_count + card.crtc_count) * sizeof(drm_crtc_t));
+		if (!crtcs) {
+			crtcs = old_crtcs;
+			return -1;
+		}
+
+		for (i = 0; i < card.crtc_count; i++) {
+			if (drm_crtc_open(i, cards + c, &crtc) < 0)
+				return -1;
+			if (crtc.connected)
+				crtcs[crtc_count++] = crtc;
+			else
+				drm_crtc_close(&crtc);
+		}
+	}
+
+	for (c = 0; c < 3; c++) {
+		brightnesses[c] = malloc(crtc_count * sizeof(double));
+		if (!brightnesses[c])
+			return -1;
+		contrasts[c] = malloc(crtc_count * sizeof(double));
+		if (!contrasts[c])
+			return -1;
+		gammas[c] = malloc(crtc_count * sizeof(double));
+		if (!gammas[c])
+			return -1;
+	}
+
+	return 0;
+}
+
+
+/**
+ * Release video control
+ */
+void
+release_video(void)
+{
+	size_t i;
+	while (crtc_count)
+		drm_crtc_close(&crtcs[--crtc_count]);
+	while (card_count)
+		drm_card_close(&cards[--card_count]);
+	while (framebuffer_count)
+		fb_close(&framebuffers[--framebuffer_count]);
+	for (i = 0; i < 3; i++) {
+		free(brightnesses[i]);
+		free(contrasts[i]);
+		free(gammas[i]);
+		brightnesses[i] = NULL;
+		contrasts[i] = NULL;
+		gammas[i] = NULL;
+	}
+	free(crtcs);
+	free(cards);
+	free(framebuffers);
+	crtcs = NULL;
+	cards = NULL;
+	framebuffers = NULL;
+}