Let backend track transform state

This will be necessary to provide it to clients via wl_output.

backend/drm/drm.c

@@ -178,6 +178,28 @@ static int find_id(const void *item, const void *cmp_to) {
 	}
 }
 
+static void wlr_drm_output_enable(struct wlr_output_state *output, bool enable) {
+	struct wlr_backend_state *state =
+		wl_container_of(output->renderer, state, renderer);
+	if (output->state != DRM_OUTPUT_CONNECTED) {
+		return;
+	}
+
+	if (enable) {
+		drmModeConnectorSetProperty(state->fd, output->connector, output->props.dpms,
+			DRM_MODE_DPMS_ON);
+
+		// Start rendering loop again by drawing a black frame
+		wlr_drm_output_begin(output);
+		glClearColor(0.0, 0.0, 0.0, 1.0);
+		glClear(GL_COLOR_BUFFER_BIT);
+		wlr_drm_output_end(output);
+	} else {
+		drmModeConnectorSetProperty(state->fd, output->connector, output->props.dpms,
+			DRM_MODE_DPMS_STANDBY);
+	}
+}
+
 static bool wlr_drm_output_set_mode(struct wlr_output_state *output,
 		struct wlr_output_mode *mode) {
 	struct wlr_backend_state *state =
@@ -251,26 +273,9 @@ error:
 	return false;
 }
 
-static void wlr_drm_output_enable(struct wlr_output_state *output, bool enable) {
-	struct wlr_backend_state *state =
-		wl_container_of(output->renderer, state, renderer);
-	if (output->state != DRM_OUTPUT_CONNECTED) {
-		return;
-	}
-
-	if (enable) {
-		drmModeConnectorSetProperty(state->fd, output->connector, output->props.dpms,
-			DRM_MODE_DPMS_ON);
-
-		// Start rendering loop again by drawing a black frame
-		wlr_drm_output_begin(output);
-		glClearColor(0.0, 0.0, 0.0, 1.0);
-		glClear(GL_COLOR_BUFFER_BIT);
-		wlr_drm_output_end(output);
-	} else {
-		drmModeConnectorSetProperty(state->fd, output->connector, output->props.dpms,
-			DRM_MODE_DPMS_STANDBY);
-	}
+static void wlr_drm_output_transform(struct wlr_output_state *output,
+		enum wl_output_transform transform) {
+	output->wlr_output->transform = transform;
 }
 
 static void wlr_drm_output_destroy(struct wlr_output_state *output) {
@@ -279,8 +284,9 @@ static void wlr_drm_output_destroy(struct wlr_output_state *output) {
 }
 
 static struct wlr_output_impl output_impl = {
-	.set_mode = wlr_drm_output_set_mode,
 	.enable = wlr_drm_output_enable,
+	.set_mode = wlr_drm_output_set_mode,
+	.transform = wlr_drm_output_transform,
 	.destroy = wlr_drm_output_destroy,
 };
 

example/rotation.c

@@ -1,4 +1,5 @@
 #define _POSIX_C_SOURCE 199309L
+#define _XOPEN_SOURCE 500
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
@@ -10,7 +11,7 @@
 #include <wlr/backend.h>
 #include <wlr/session.h>
 #include <wlr/types.h>
-#include <tgmath.h>
+#include <math.h>
 
 static const GLchar vert_src[] =
 "#version 310 es\n"
@@ -92,7 +93,6 @@ struct output_state {
 	struct wlr_output *output;
 	struct state *state;
 	struct wl_listener frame;
-	enum wl_output_transform transform;
 };
 
 struct output_config {
@@ -177,7 +177,7 @@ static void output_frame(struct wl_listener *listener, void *data) {
 	glViewport(0, 0, width, height);
 
 	// All of the odd numbered transformations involve a 90 or 270 degree rotation
-	if (ostate->transform % 2 == 1) {
+	if (ostate->output->transform % 2 == 1) {
 		float tmp = width;
 		width = height;
 		height = tmp;
@@ -199,7 +199,7 @@ static void output_frame(struct wl_listener *listener, void *data) {
 	glBindBuffer(GL_ARRAY_BUFFER, s->gl.vbo);
 	glBufferData(GL_ARRAY_BUFFER, sizeof(vert_data), vert_data, GL_STATIC_DRAW);
 
-	glUniformMatrix2fv(0, 1, GL_FALSE, transforms[ostate->transform]);
+	glUniformMatrix2fv(0, 1, GL_FALSE, transforms[ostate->output->transform]);
 
 	glClearColor(0.0, 0.0, 0.0, 1.0);
 	glClear(GL_COLOR_BUFFER_BIT);
@@ -214,7 +214,7 @@ static void output_frame(struct wl_listener *listener, void *data) {
 
 	s->last_frame = now;
 	s->angle += ms / 200.0f;
-	if (s->angle > 6.28318530718f) { // 2 pi
+	if (s->angle > 2 * M_PI) {
 		s->angle = 0.0f;
 	}
 }
@@ -231,12 +231,11 @@ static void output_add(struct wl_listener *listener, void *data) {
 	ostate->output = output;
 	ostate->state = state;
 	ostate->frame.notify = output_frame;
-	ostate->transform = WL_OUTPUT_TRANSFORM_NORMAL;
 
 	struct output_config *conf;
 	wl_list_for_each(conf, &state->config, link) {
 		if (strcmp(conf->name, output->name) == 0) {
-			ostate->transform = conf->transform;
+			wlr_output_transform(ostate->output, conf->transform);
 			break;
 		}
 	}

include/types.h

@@ -6,8 +6,11 @@
 #include <stdbool.h>
 
 struct wlr_output_impl {
-	bool (*set_mode)(struct wlr_output_state *state, struct wlr_output_mode *mode);
 	void (*enable)(struct wlr_output_state *state, bool enable);
+	bool (*set_mode)(struct wlr_output_state *state,
+			struct wlr_output_mode *mode);
+	void (*transform)(struct wlr_output_state *state,
+			enum wl_output_transform transform);
 	void (*destroy)(struct wlr_output_state *state);
 };
 

include/wlr/types.h

@@ -40,8 +40,11 @@ struct wlr_output {
 	} events;
 };
 
-bool wlr_output_set_mode(struct wlr_output *output, struct wlr_output_mode *mode);
 void wlr_output_enable(struct wlr_output *output, bool enable);
+bool wlr_output_set_mode(struct wlr_output *output,
+		struct wlr_output_mode *mode);
+void wlr_output_transform(struct wlr_output *output,
+		enum wl_output_transform transform);
 void wlr_output_destroy(struct wlr_output *output);
 
 #endif

types/wlr_output.c

@@ -10,10 +10,24 @@ struct wlr_output *wlr_output_create(struct wlr_output_impl *impl,
 	output->impl = impl;
 	output->state = state;
 	output->modes = list_create();
+	output->transform = WL_OUTPUT_TRANSFORM_NORMAL;
 	wl_signal_init(&output->events.frame);
 	return output;
 }
 
+void wlr_output_enable(struct wlr_output *output, bool enable) {
+	output->impl->enable(output->state, enable);
+}
+
+bool wlr_output_set_mode(struct wlr_output *output, struct wlr_output_mode *mode) {
+	return output->impl->set_mode(output->state, mode);
+}
+
+void wlr_output_transform(struct wlr_output *output,
+		enum wl_output_transform transform) {
+	output->impl->transform(output->state, transform);
+}
+
 void wlr_output_destroy(struct wlr_output *output) {
 	if (!output) return;
 	output->impl->destroy(output->state);
@@ -25,11 +39,3 @@ void wlr_output_destroy(struct wlr_output *output) {
 	list_free(output->modes);
 	free(output);
 }
-
-bool wlr_output_set_mode(struct wlr_output *output, struct wlr_output_mode *mode) {
-	return output->impl->set_mode(output->state, mode);
-}
-
-void wlr_output_enable(struct wlr_output *output, bool enable) {
-	output->impl->enable(output->state, enable);
-}