output: make gamma size a size_t and gamma table const

backend/drm/atomic.c

@@ -200,14 +200,14 @@ static bool atomic_crtc_move_cursor(struct wlr_drm_backend *drm,
 }
 
 static bool atomic_crtc_set_gamma(struct wlr_drm_backend *drm,
-		struct wlr_drm_crtc *crtc, uint16_t *r, uint16_t *g, uint16_t *b,
+		struct wlr_drm_crtc *crtc, size_t size,
-		uint32_t size) {
+		uint16_t *r, uint16_t *g, uint16_t *b) {
 	// Fallback to legacy gamma interface when gamma properties are not available
 	// (can happen on older intel gpu's that support gamma but not degamma)
 	// TEMP: This is broken on AMDGPU. Always fallback to legacy until they get
 	// it fixed. Ref https://bugs.freedesktop.org/show_bug.cgi?id=107459
 	if (crtc->props.gamma_lut == 0 || true) {
-		return legacy_iface.crtc_set_gamma(drm, crtc, r, g, b, size);
+		return legacy_iface.crtc_set_gamma(drm, crtc, size, r, g, b);
 	}
 
 	struct drm_color_lut *gamma = malloc(size * sizeof(struct drm_color_lut));
@@ -216,7 +216,7 @@ static bool atomic_crtc_set_gamma(struct wlr_drm_backend *drm,
 		return false;
 	}
 
-	for (uint32_t i = 0; i < size; i++) {
+	for (size_t i = 0; i < size; i++) {
 		gamma[i].red = r[i];
 		gamma[i].green = g[i];
 		gamma[i].blue = b[i];
@@ -240,21 +240,20 @@ static bool atomic_crtc_set_gamma(struct wlr_drm_backend *drm,
 	return atomic_end(drm->fd, &atom);
 }
 
-static uint32_t atomic_crtc_get_gamma_size(struct wlr_drm_backend *drm,
+static size_t atomic_crtc_get_gamma_size(struct wlr_drm_backend *drm,
 		struct wlr_drm_crtc *crtc) {
-	uint64_t gamma_lut_size;
-
 	if (crtc->props.gamma_lut_size == 0) {
 		return legacy_iface.crtc_get_gamma_size(drm, crtc);
 	}
 
+	uint64_t gamma_lut_size;
 	if (!get_drm_prop(drm->fd, crtc->id, crtc->props.gamma_lut_size,
-			   &gamma_lut_size)) {
+			&gamma_lut_size)) {
 		wlr_log(WLR_ERROR, "Unable to get gamma lut size");
 		return 0;
 	}
 
-	return (uint32_t)gamma_lut_size;
+	return (size_t)gamma_lut_size;
 }
 
 const struct wlr_drm_interface atomic_iface = {

backend/drm/drm.c

@@ -251,7 +251,7 @@ static bool drm_connector_swap_buffers(struct wlr_output *output,
 	return true;
 }
 
-static void fill_empty_gamma_table(uint32_t size,
+static void fill_empty_gamma_table(size_t size,
 		uint16_t *r, uint16_t *g, uint16_t *b) {
 	for (uint32_t i = 0; i < size; ++i) {
 		uint16_t val = (uint32_t)0xffff * i / (size - 1);
@@ -259,7 +259,7 @@ static void fill_empty_gamma_table(uint32_t size,
 	}
 }
 
-static uint32_t drm_connector_get_gamma_size(struct wlr_output *output) {
+static size_t drm_connector_get_gamma_size(struct wlr_output *output) {
 	struct wlr_drm_connector *conn = get_drm_connector_from_output(output);
 	struct wlr_drm_backend *drm = get_drm_backend_from_backend(output->backend);
 
@@ -270,8 +270,8 @@ static uint32_t drm_connector_get_gamma_size(struct wlr_output *output) {
 	return 0;
 }
 
-static bool drm_connector_set_gamma(struct wlr_output *output,
+static bool drm_connector_set_gamma(struct wlr_output *output, size_t size,
-		uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b) {
+		const uint16_t *r, const uint16_t *g, const uint16_t *b) {
 	struct wlr_drm_connector *conn = get_drm_connector_from_output(output);
 	struct wlr_drm_backend *drm = get_drm_backend_from_backend(output->backend);
 
@@ -279,25 +279,37 @@ static bool drm_connector_set_gamma(struct wlr_output *output,
 		return false;
 	}
 
-	uint16_t *reset_table = NULL;
+	bool reset = false;
 	if (size == 0) {
+		reset = true;
 		size = drm_connector_get_gamma_size(output);
-		reset_table = malloc(3 * size * sizeof(uint16_t));
+		if (size == 0) {
-		if (reset_table == NULL) {
-			wlr_log(WLR_ERROR, "Failed to allocate gamma table");
 			return false;
 		}
-		r = reset_table;
-		g = reset_table + size;
-		b = reset_table + 2 * size;
-		fill_empty_gamma_table(size, r, g, b);
 	}
 
-	bool ok = drm->iface->crtc_set_gamma(drm, conn->crtc, r, g, b, size);
+	uint16_t *gamma_table = malloc(3 * size * sizeof(uint16_t));
+	if (gamma_table == NULL) {
+		wlr_log(WLR_ERROR, "Failed to allocate gamma table");
+		return false;
+	}
+	uint16_t *_r = gamma_table;
+	uint16_t *_g = gamma_table + size;
+	uint16_t *_b = gamma_table + 2 * size;
+
+	if (reset) {
+		fill_empty_gamma_table(size, _r, _g, _b);
+	} else {
+		memcpy(_r, r, size * sizeof(uint16_t));
+		memcpy(_g, g, size * sizeof(uint16_t));
+		memcpy(_b, b, size * sizeof(uint16_t));
+	}
+
+	bool ok = drm->iface->crtc_set_gamma(drm, conn->crtc, size, _r, _g, _b);
 	if (ok) {
 		wlr_output_update_needs_swap(output);
 	}
-	free(reset_table);
+	free(gamma_table);
 	return ok;
 }
 

backend/drm/legacy.c

@@ -63,14 +63,14 @@ bool legacy_crtc_move_cursor(struct wlr_drm_backend *drm,
 }
 
 bool legacy_crtc_set_gamma(struct wlr_drm_backend *drm,
-		struct wlr_drm_crtc *crtc, uint16_t *r, uint16_t *g, uint16_t *b,
+		struct wlr_drm_crtc *crtc, size_t size,
-		uint32_t size) {
+		uint16_t *r, uint16_t *g, uint16_t *b) {
-	return !drmModeCrtcSetGamma(drm->fd, crtc->id, size, r, g, b);
+	return !drmModeCrtcSetGamma(drm->fd, crtc->id, (uint32_t)size, r, g, b);
 }
 
-uint32_t legacy_crtc_get_gamma_size(struct wlr_drm_backend *drm,
+size_t legacy_crtc_get_gamma_size(struct wlr_drm_backend *drm,
 		struct wlr_drm_crtc *crtc) {
-	return crtc->legacy_crtc->gamma_size;
+	return (size_t)crtc->legacy_crtc->gamma_size;
 }
 
 const struct wlr_drm_interface legacy_iface = {

include/backend/drm/iface.h

@@ -28,11 +28,11 @@ struct wlr_drm_interface {
 		struct wlr_drm_crtc *crtc, int x, int y);
 	// Set the gamma lut on crtc
 	bool (*crtc_set_gamma)(struct wlr_drm_backend *drm,
-			struct wlr_drm_crtc *crtc, uint16_t *r, uint16_t *g, uint16_t *b,
+		struct wlr_drm_crtc *crtc, size_t size,
-			uint32_t size);
+		uint16_t *r, uint16_t *g, uint16_t *b);
 	// Get the gamma lut size of a crtc
-	uint32_t (*crtc_get_gamma_size)(struct wlr_drm_backend *drm,
+	size_t (*crtc_get_gamma_size)(struct wlr_drm_backend *drm,
-			struct wlr_drm_crtc *crtc);
+		struct wlr_drm_crtc *crtc);
 };
 
 extern const struct wlr_drm_interface atomic_iface;

include/wlr/interfaces/wlr_output.h

@@ -28,9 +28,9 @@ struct wlr_output_impl {
 	void (*destroy)(struct wlr_output *output);
 	bool (*make_current)(struct wlr_output *output, int *buffer_age);
 	bool (*swap_buffers)(struct wlr_output *output, pixman_region32_t *damage);
-	bool (*set_gamma)(struct wlr_output *output,
+	bool (*set_gamma)(struct wlr_output *output, size_t size,
-		uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);
+		const uint16_t *r, const uint16_t *g, const uint16_t *b);
-	uint32_t (*get_gamma_size)(struct wlr_output *output);
+	size_t (*get_gamma_size)(struct wlr_output *output);
 	bool (*export_dmabuf)(struct wlr_output *output,
 		struct wlr_dmabuf_attributes *attribs);
 };

include/wlr/types/wlr_output.h

@@ -182,7 +182,7 @@ void wlr_output_schedule_frame(struct wlr_output *output);
 /**
  * Returns the maximum length of each gamma ramp, or 0 if unsupported.
  */
-uint32_t wlr_output_get_gamma_size(struct wlr_output *output);
+size_t wlr_output_get_gamma_size(struct wlr_output *output);
 /**
  * Sets the gamma table for this output. `r`, `g` and `b` are gamma ramps for
  * red, green and blue. `size` is the length of the ramps and must not exceed
@@ -190,8 +190,8 @@ uint32_t wlr_output_get_gamma_size(struct wlr_output *output);
  *
  * Providing zero-sized ramps resets the gamma table.
  */
-bool wlr_output_set_gamma(struct wlr_output *output,
+bool wlr_output_set_gamma(struct wlr_output *output, size_t size,
-	uint32_t size, uint16_t *r, uint16_t *g, uint16_t *b);
+	const uint16_t *r, const uint16_t *g, const uint16_t *b);
 bool wlr_output_export_dmabuf(struct wlr_output *output,
 	struct wlr_dmabuf_attributes *attribs);
 void wlr_output_set_fullscreen_surface(struct wlr_output *output,

types/wlr_output.c

@@ -560,15 +560,15 @@ void wlr_output_schedule_frame(struct wlr_output *output) {
 		wl_event_loop_add_idle(ev, schedule_frame_handle_idle_timer, output);
 }
 
-bool wlr_output_set_gamma(struct wlr_output *output, uint32_t size,
+bool wlr_output_set_gamma(struct wlr_output *output, size_t size,
-		uint16_t *r, uint16_t *g, uint16_t *b) {
+		const uint16_t *r, const uint16_t *g, const uint16_t *b) {
 	if (!output->impl->set_gamma) {
 		return false;
 	}
 	return output->impl->set_gamma(output, size, r, g, b);
 }
 
-uint32_t wlr_output_get_gamma_size(struct wlr_output *output) {
+size_t wlr_output_get_gamma_size(struct wlr_output *output) {
 	if (!output->impl->get_gamma_size) {
 		return 0;
 	}