1 files changed, 356 insertions, 0 deletions
diff --git a/example/rotation.c b/example/rotation.c
new file mode 100644
index 00000000..d19af224
--- /dev/null
+++ b/example/rotation.c
@@ -0,0 +1,356 @@
+#define _POSIX_C_SOURCE 199309L
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <unistd.h>
+#include <wayland-server.h>
+#include <wayland-server-protocol.h>
+#include <GLES3/gl3.h>
+#include <wlr/backend.h>
+#include <wlr/session.h>
+#include <wlr/types.h>
+#include <math.h>
+
+static const GLchar vert_src[] =
+"#version 310 es\n"
+"precision mediump float;\n"
+"layout(location = 0) uniform mat4 transform;\n"
+"layout(location = 0) in vec2 pos;\n"
+"layout(location = 1) in float angle;\n"
+"out float v_angle;\n"
+"void main() {\n"
+"	v_angle = angle;\n"
+"	gl_Position = transform * vec4(pos, 0.0, 1.0);\n"
+"}\n";
+
+static const GLchar frag_src[] =
+"#version 310 es\n"
+"precision mediump float;\n"
+"in float v_angle;\n"
+"out vec4 f_color;\n"
+"void main() {\n"
+"	f_color = vec4(\n"
+"		cos(v_angle) / 2.0 + 0.5,\n"
+"		cos(v_angle + 2.0944) / 2.0 + 0.5,\n"
+"		cos(v_angle + 4.18879) / 2.0 + 0.5,\n"
+"		1.0);\n"
+"}\n";
+
+struct state {
+	float angle;
+	struct timespec last_frame;
+	struct wl_listener output_add;
+	struct wl_listener output_remove;
+	struct wl_list outputs;
+	struct wl_list config;
+
+	struct gl {
+		GLuint prog;
+		GLuint vao;
+		GLuint vbo;
+	} gl;
+};
+
+struct output_state {
+	struct wl_list link;
+	struct wlr_output *output;
+	struct state *state;
+	struct wl_listener frame;
+};
+
+struct output_config {
+	char *name;
+	enum wl_output_transform transform;
+
+	struct wl_list link;
+};
+
+static GLuint create_shader(GLenum type, const GLchar *src, GLint len) {
+	GLuint shader = glCreateShader(type);
+	glShaderSource(shader, 1, &src, &len);
+	glCompileShader(shader);
+
+	GLint success;
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+
+	if (success == GL_FALSE) {
+		GLint loglen;
+		glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &loglen);
+
+		GLchar msg[loglen];
+		glGetShaderInfoLog(shader, loglen, &loglen, msg);
+
+		fprintf(stderr, "Failed to create shader: %s\n", msg);
+		exit(1);
+	}
+
+	return shader;
+}
+
+static void init_gl(struct gl *gl) {
+	GLuint vert = create_shader(GL_VERTEX_SHADER, vert_src, strlen(vert_src));
+	GLuint frag = create_shader(GL_FRAGMENT_SHADER, frag_src, strlen(frag_src));
+
+	gl->prog = glCreateProgram();
+	glAttachShader(gl->prog, vert);
+	glAttachShader(gl->prog, frag);
+	glLinkProgram(gl->prog);
+
+	GLint success;
+	glGetProgramiv(gl->prog, GL_LINK_STATUS, &success);
+
+	if (success == GL_FALSE) {
+		GLint len;
+		glGetProgramiv(gl->prog, GL_INFO_LOG_LENGTH, &len);
+
+		GLchar msg[len];
+		glGetProgramInfoLog(gl->prog, len, &len, msg);
+
+		fprintf(stderr, "Failed to link program: %s\n", msg);
+		exit(1);
+	}
+
+	glDeleteProgram(vert);
+	glDeleteProgram(frag);
+
+	glGenVertexArrays(1, &gl->vao);
+	glGenBuffers(1, &gl->vbo);
+
+	glBindVertexArray(gl->vao);
+	glBindBuffer(GL_ARRAY_BUFFER, gl->vbo);
+
+	glEnableVertexAttribArray(0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (void *)0);
+	glVertexAttribPointer(1, 1, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (void *)(2 * sizeof(GLfloat)));
+}
+
+static void cleanup_gl(struct gl *gl) {
+	glDeleteProgram(gl->prog);
+	glDeleteVertexArrays(1, &gl->vao);
+	glDeleteBuffers(1, &gl->vbo);
+}
+
+static void output_frame(struct wl_listener *listener, void *data) {
+	struct output_state *ostate = wl_container_of(listener, ostate, frame);
+	struct state *s = ostate->state;
+
+	int32_t width = ostate->output->width;
+	int32_t height = ostate->output->height;
+	glViewport(0, 0, width, height);
+
+	// All of the odd numbered transformations involve a 90 or 270 degree rotation
+	if (ostate->output->transform % 2 == 1) {
+		float tmp = width;
+		width = height;
+		height = tmp;
+	}
+
+	int32_t mid_w = width / 2;
+	int32_t mid_h = height / 2;
+
+	GLfloat vert_data[] = {
+		mid_w - 200, mid_h - 200, s->angle,
+		mid_w, mid_h + 200, s->angle + M_PI * 2.0f / 3.0f, // 120 deg
+		mid_w + 200, mid_h - 200, s->angle + M_PI * 4.0f / 3.0f, // 240 deg
+	};
+
+	glUseProgram(s->gl.prog);
+
+	glBindVertexArray(s->gl.vao);
+	glBindBuffer(GL_ARRAY_BUFFER, s->gl.vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vert_data), vert_data, GL_STATIC_DRAW);
+
+	glUniformMatrix4fv(0, 1, GL_TRUE, ostate->output->transform_matrix);
+
+	glClearColor(0.0, 0.0, 0.0, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	glDrawArrays(GL_TRIANGLE_STRIP, 0, 3);
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	long ms = (now.tv_sec - s->last_frame.tv_sec) * 1000 +
+		(now.tv_nsec - s->last_frame.tv_nsec) / 1000000;
+
+	s->last_frame = now;
+	s->angle += ms / 200.0f;
+	if (s->angle > 2 * M_PI) {
+		s->angle = 0.0f;
+	}
+}
+
+static void output_add(struct wl_listener *listener, void *data) {
+	struct wlr_output *output = data;
+	struct state *state = wl_container_of(listener, state, output_add);
+
+	fprintf(stderr, "Output '%s' added\n", output->name);
+	wlr_output_set_mode(output, output->modes->items[0]);
+
+	struct output_state *ostate = calloc(1, sizeof(struct output_state));
+
+	ostate->output = output;
+	ostate->state = state;
+	ostate->frame.notify = output_frame;
+
+	struct output_config *conf;
+	wl_list_for_each(conf, &state->config, link) {
+		if (strcmp(conf->name, output->name) == 0) {
+			wlr_output_transform(ostate->output, conf->transform);
+			break;
+		}
+	}
+
+	wl_list_init(&ostate->frame.link);
+	wl_signal_add(&output->events.frame, &ostate->frame);
+	wl_list_insert(&state->outputs, &ostate->link);
+}
+
+static void output_remove(struct wl_listener *listener, void *data) {
+	struct wlr_output *output = data;
+	struct state *state = wl_container_of(listener, state, output_remove);
+	struct output_state *ostate;
+
+	wl_list_for_each(ostate, &state->outputs, link) {
+		if (ostate->output == output) {
+			wl_list_remove(&ostate->link);
+			wl_list_remove(&ostate->frame.link);
+			free(ostate);
+			break;
+		}
+	}
+}
+
+static int timer_done(void *data) {
+	*(bool *)data = true;
+	return 1;
+}
+
+static void usage(const char *name, int ret) {
+	fprintf(stderr,
+		"usage: %s [-d <name> [-r <rotation> | -f]]*\n"
+		"\n"
+		" -o <output>    The name of the DRM display. e.g. DVI-I-1.\n"
+		" -r <rotation>  The rotation counter clockwise. Valid values are 90, 180, 270.\n"
+		" -f             Flip the output along the vertical axis.\n", name);
+
+	exit(ret);
+}
+
+static void parse_args(int argc, char *argv[], struct wl_list *config) {
+	struct output_config *oc = NULL;
+
+	int c;
+	while ((c = getopt(argc, argv, "o:r:fh")) != -1) {
+		switch (c) {
+		case 'o':
+			oc = calloc(1, sizeof(*oc));
+			oc->name = optarg;
+			oc->transform = WL_OUTPUT_TRANSFORM_NORMAL;
+			wl_list_insert(config, &oc->link);
+			break;
+		case 'r':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+
+			if (oc->transform != WL_OUTPUT_TRANSFORM_NORMAL
+					&& oc->transform != WL_OUTPUT_TRANSFORM_FLIPPED) {
+				fprintf(stderr, "Rotation for %s already specified\n", oc->name);
+				usage(argv[0], 1);
+			}
+
+			if (strcmp(optarg, "90") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_90;
+			} else if (strcmp(optarg, "180") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_180;
+			} else if (strcmp(optarg, "270") == 0) {
+				oc->transform += WL_OUTPUT_TRANSFORM_270;
+			} else {
+				fprintf(stderr, "Invalid rotation '%s'\n", optarg);
+				usage(argv[0], 1);
+			}
+			break;
+		case 'f':
+			if (!oc) {
+				fprintf(stderr, "You must specify an output first\n");
+				usage(argv[0], 1);
+			}
+
+			if (oc->transform >= WL_OUTPUT_TRANSFORM_FLIPPED) {
+				fprintf(stderr, "Flip for %s already specified\n", oc->name);
+				usage(argv[0], 1);
+			}
+
+			oc->transform += WL_OUTPUT_TRANSFORM_FLIPPED;
+			break;
+		case 'h':
+		case '?':
+			usage(argv[0], c != 'h');
+		}
+	}
+}
+
+int main(int argc, char *argv[]) {
+	struct state state = {
+		.angle = 0.0,
+		.output_add = { .notify = output_add },
+		.output_remove = { .notify = output_remove }
+	};
+
+	wl_list_init(&state.outputs);
+	wl_list_init(&state.config);
+	wl_list_init(&state.output_add.link);
+	wl_list_init(&state.output_remove.link);
+	clock_gettime(CLOCK_MONOTONIC, &state.last_frame);
+
+	parse_args(argc, argv, &state.config);
+
+	struct wl_display *display = wl_display_create();
+	struct wl_event_loop *event_loop = wl_display_get_event_loop(display);
+
+	struct wlr_session *session = wlr_session_start(display);
+	if (!session) {
+		return 1;
+	}
+
+	struct wlr_backend *wlr = wlr_backend_autocreate(display, session);
+	if (!wlr) {
+		return 1;
+	}
+
+	wl_signal_add(&wlr->events.output_add, &state.output_add);
+	wl_signal_add(&wlr->events.output_remove, &state.output_remove);
+
+	if (!wlr_backend_init(wlr)) {
+		return 1;
+	}
+
+	init_gl(&state.gl);
+
+	bool done = false;
+	struct wl_event_source *timer = wl_event_loop_add_timer(event_loop,
+		timer_done, &done);
+
+	wl_event_source_timer_update(timer, 10000);
+
+	while (!done) {
+		wl_event_loop_dispatch(event_loop, 0);
+	}
+
+	cleanup_gl(&state.gl);
+
+	wl_event_source_remove(timer);
+	wlr_backend_destroy(wlr);
+	wlr_session_finish(session);
+	wl_display_destroy(display);
+
+	struct output_config *ptr, *tmp;
+	wl_list_for_each_safe(ptr, tmp, &state.config, link) {
+		free(ptr);
+	}
+}