Add colored quad and ellipse rendering primitives

example/CMakeLists.txt

@@ -53,3 +53,15 @@ target_link_libraries(touch
     wlr-render
     ${XKBCOMMON_LIBRARIES}
 )
+
+add_executable(tablet
+    tablet.c
+    shared.c
+)
+
+target_link_libraries(tablet
+    wlr-backend
+    wlr-session
+    wlr-render
+    ${XKBCOMMON_LIBRARIES}
+)

example/tablet.c

@@ -0,0 +1,63 @@
+#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 <xkbcommon/xkbcommon.h>
+#include <GLES3/gl3.h>
+#include <wlr/render/matrix.h>
+#include <wlr/render/gles3.h>
+#include <wlr/render.h>
+#include <wlr/backend.h>
+#include <wlr/session.h>
+#include <wlr/types.h>
+#include <math.h>
+#include "shared.h"
+#include "cat.h"
+
+struct sample_state {
+	struct wlr_renderer *renderer;
+};
+
+static void handle_output_frame(struct output_state *output, struct timespec *ts) {
+	struct compositor_state *state = output->compositor;
+	struct sample_state *sample = state->data;
+	struct wlr_output *wlr_output = output->output;
+
+	wlr_renderer_begin(sample->renderer, wlr_output);
+
+	float matrix[16];
+	float color[4] = { 0, 1.0, 0, 1.0 };
+	wlr_matrix_scale(&matrix, 128, 128, 1);
+	wlr_matrix_mul(&wlr_output->transform_matrix, &matrix, &matrix);
+	wlr_render_colored_ellipse(sample->renderer, &color, &matrix);
+
+	wlr_renderer_end(sample->renderer);
+}
+
+static void handle_keyboard_key(struct keyboard_state *kbstate,
+		xkb_keysym_t sym, enum wlr_key_state key_state) {
+	if (sym == XKB_KEY_Escape) {
+		kbstate->compositor->exit = true;
+	}
+}
+
+int main(int argc, char *argv[]) {
+	struct sample_state state = { 0 };
+	struct compositor_state compositor;
+
+	compositor_init(&compositor);
+	compositor.output_frame_cb = handle_output_frame;
+	compositor.keyboard_key_cb = handle_keyboard_key;
+
+	state.renderer = wlr_gles3_renderer_init();
+
+	compositor.data = &state;
+	compositor_run(&compositor);
+
+	wlr_renderer_destroy(state.renderer);
+}

include/render/gles3.h

@@ -13,6 +13,9 @@ struct wlr_surface_state {
 
 struct wlr_surface *gles3_surface_init();
 
+extern const GLchar quad_vertex_src[];
+extern const GLchar quad_fragment_src[];
+extern const GLchar ellipse_fragment_src[];
 extern const GLchar vertex_src[];
 extern const GLchar fragment_src_RGB[];
 extern const GLchar fragment_src_RGBA[];

include/wlr/render.h

@@ -28,6 +28,16 @@ struct wlr_surface *wlr_render_surface_init(struct wlr_renderer *r);
  */
 bool wlr_render_with_matrix(struct wlr_renderer *r,
 		struct wlr_surface *surface, const float (*matrix)[16]);
+/**
+ * Renders a solid quad in the specified color.
+ */
+void wlr_render_colored_quad(struct wlr_renderer *r,
+		const float (*color)[4], const float (*matrix)[16]);
+/**
+ * Renders a solid ellipse in the specified color.
+ */
+void wlr_render_colored_ellipse(struct wlr_renderer *r,
+		const float (*color)[4], const float (*matrix)[16]);
 /**
  * Destroys this wlr_renderer. Surfaces must be destroyed separately.
  */

include/wlr/render/interface.h

@@ -19,6 +19,10 @@ struct wlr_renderer_impl {
 	struct wlr_surface *(*surface_init)(struct wlr_renderer_state *state);
 	bool (*render_with_matrix)(struct wlr_renderer_state *state,
 		struct wlr_surface *surface, const float (*matrix)[16]);
+	void (*render_quad)(struct wlr_renderer_state *state,
+			const float (*color)[4], const float (*matrix)[16]);
+	void (*render_ellipse)(struct wlr_renderer_state *state,
+			const float (*color)[4], const float (*matrix)[16]);
 	void (*destroy)(struct wlr_renderer_state *state);
 };
 

render/gles3/renderer.c

@@ -13,6 +13,8 @@
 static struct {
 	bool initialized;
 	GLuint rgb, rgba;
+	GLuint quad;
+	GLuint ellipse;
 } shaders;
 static GLuint vao, vbo, ebo;
 
@@ -28,6 +30,9 @@ static bool compile_shader(GLuint type, const GLchar *src, GLuint *shader) {
 		GL_CALL(glGetShaderiv(*shader, GL_INFO_LOG_LENGTH, &loglen));
 		GLchar msg[loglen];
 		GL_CALL(glGetShaderInfoLog(*shader, loglen, &loglen, msg));
+		wlr_log(L_ERROR, "Shader compilation failed");
+		wlr_log(L_ERROR, "%s", msg);
+		exit(1);
 		return false;
 	}
 	return true;
@@ -60,6 +65,12 @@ static void init_default_shaders() {
 	if (!compile_program(vertex_src, fragment_src_RGBA, &shaders.rgba)) {
 		goto error;
 	}
+	if (!compile_program(quad_vertex_src, quad_fragment_src, &shaders.quad)) {
+		goto error;
+	}
+	if (!compile_program(quad_vertex_src, ellipse_fragment_src, &shaders.ellipse)) {
+		goto error;
+	}
 	return;
 error:
 	wlr_log(L_ERROR, "Failed to set up default shaders!");
@@ -141,6 +152,28 @@ static bool wlr_gles3_render_surface(struct wlr_renderer_state *state,
 	return true;
 }
 
+static void wlr_gles3_render_quad(struct wlr_renderer_state *state,
+		const float (*color)[4], const float (*matrix)[16]) {
+	GL_CALL(glUseProgram(shaders.quad));
+	GL_CALL(glBindVertexArray(vao));
+	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
+	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
+	GL_CALL(glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0));
+}
+
+static void wlr_gles3_render_ellipse(struct wlr_renderer_state *state,
+		const float (*color)[4], const float (*matrix)[16]) {
+	GL_CALL(glUseProgram(shaders.ellipse));
+	GL_CALL(glBindVertexArray(vao));
+	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
+	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
+	GL_CALL(glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0));
+}
+
 static void wlr_gles3_destroy(struct wlr_renderer_state *state) {
 	// no-op
 }
@@ -150,6 +183,8 @@ static struct wlr_renderer_impl wlr_renderer_impl = {
 	.end = wlr_gles3_end,
 	.surface_init = wlr_gles3_surface_init,
 	.render_with_matrix = wlr_gles3_render_surface,
+	.render_quad = wlr_gles3_render_quad,
+	.render_ellipse = wlr_gles3_render_ellipse,
 	.destroy = wlr_gles3_destroy
 };
 

render/gles3/shaders.c

@@ -1,28 +1,63 @@
 #include "render/gles3.h"
 #include <GLES3/gl3.h>
 
+// Colored quads
+const GLchar quad_vertex_src[] =
+"uniform mat4 proj;"
+"uniform vec4 color;"
+"attribute vec2 pos;"
+"attribute vec2 texcoord;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  gl_Position = proj * vec4(pos, 0.0, 1.0);"
+"  v_color = color;"
+"  v_texcoord = texcoord;"
+"}";
+
+const GLchar quad_fragment_src[] =
+"precision mediump float;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  gl_FragColor = v_color;"
+"}";
+
+// Colored ellipses (TODO)
+
+const GLchar ellipse_fragment_src[] =
+"precision mediump float;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  float l = length(v_texcoord - vec2(0.5, 0.5));"
+"  if (l > 0.5) discard;"
+"  gl_FragColor = v_color;"
+"}";
+
+// Textured quads
 const GLchar vertex_src[] =
-"uniform mat4 proj;\n"
+"uniform mat4 proj;"
-"attribute vec2 pos;\n"
+"attribute vec2 pos;"
-"attribute vec2 texcoord;\n"
+"attribute vec2 texcoord;"
-"varying vec2 v_texcoord;\n"
+"varying vec2 v_texcoord;"
-"void main() {\n"
+"void main() {"
-"	gl_Position = proj * vec4(pos, 0.0, 1.0);\n"
+"	gl_Position = proj * vec4(pos, 0.0, 1.0);"
-"	v_texcoord = texcoord;\n"
+"	v_texcoord = texcoord;"
-"}\n";
+"}";
 
 const GLchar fragment_src_RGB[] =
-"precision mediump float;\n"
+"precision mediump float;"
-"varying vec2 v_texcoord;\n"
+"varying vec2 v_texcoord;"
-"uniform sampler2D tex;\n"
+"uniform sampler2D tex;"
-"void main() {\n"
+"void main() {"
-"	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0);\n"
+"	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0);"
-"}\n";
+"}";
 
 const GLchar fragment_src_RGBA[] =
-"precision mediump float;\n"
+"precision mediump float;"
-"varying vec2 v_texcoord;\n"
+"varying vec2 v_texcoord;"
-"uniform sampler2D tex;\n"
+"uniform sampler2D tex;"
-"void main() {\n"
+"void main() {"
-"	gl_FragColor = texture2D(tex, v_texcoord);\n"
+"	gl_FragColor = texture2D(tex, v_texcoord);"
-"}\n";
+"}";

render/wlr_renderer.c

@@ -31,3 +31,13 @@ bool wlr_render_with_matrix(struct wlr_renderer *r,
 		struct wlr_surface *surface, const float (*matrix)[16]) {
 	return r->impl->render_with_matrix(r->state, surface, matrix);
 }
+
+void wlr_render_colored_quad(struct wlr_renderer *r,
+		const float (*color)[4], const float (*matrix)[16]) {
+	r->impl->render_quad(r->state, color, matrix);
+}
+
+void wlr_render_colored_ellipse(struct wlr_renderer *r,
+		const float (*color)[4], const float (*matrix)[16]) {
+	r->impl->render_ellipse(r->state, color, matrix);
+}