render: Get damage checking working

include/render.h

@@ -18,6 +18,7 @@
 
 #include <GLES2/gl2.h>
 #include <EGL/egl.h>
+#include <pixman.h>
 
 struct dmabuf_frame;
 
@@ -25,12 +26,15 @@ struct renderer {
 	EGLDisplay display;
 	EGLSurface surface;
 	EGLContext context;
+	GLuint last_texture;
 	GLuint dmabuf_shader_program;
 	GLuint texture_shader_program;
+	GLuint damage_shader_program;
 	uint32_t width;
 	uint32_t height;
 	GLint read_format;
 	GLint read_type;
+	struct pixman_region16 current_damage;
 };
 
 int renderer_init(struct renderer* self, uint32_t width, uint32_t height);
@@ -43,3 +47,5 @@ int render_framebuffer(struct renderer* self, const void* addr, uint32_t format,
 /* Copy a horizontal stripe from the GL frame into a pixel buffer */
 void render_copy_pixels(struct renderer* self, void* dst, uint32_t y,
                         uint32_t height);
+
+void render_check_damage(struct renderer* self, GLenum target, GLuint tex);

shaders/dmabuf-fragment.glsl

@@ -0,0 +1,12 @@
+#extension GL_OES_EGL_image_external: require
+
+precision mediump float;
+
+uniform samplerExternalOES u_tex;
+
+varying vec2 v_texture;
+
+void main()
+{
+	gl_FragColor = texture2D(u_tex, v_texture);
+}

shaders/dmabuf-vertex.glsl

@@ -0,0 +1,10 @@
+attribute vec2 pos;
+attribute vec2 texture;
+
+varying vec2 v_texture;
+
+void main()
+{
+	v_texture = vec2(texture.s, 1.0 - texture.t);
+	gl_Position = vec4(pos, 0, 1);
+}

shaders/texture-damage-fragment.glsl

@@ -0,0 +1,44 @@
+precision mediump float;
+
+uniform sampler2D tex0;
+uniform sampler2D tex1;
+
+varying vec2 v_texture;
+varying float v_width;
+varying float v_height;
+
+float get_pixel_damage(vec2 coord)
+{
+	vec3 diff = texture2D(tex0, coord).rgb - texture2D(tex1, coord).rgb;
+
+	vec3 absdiff = ceil(abs(diff));
+
+	return clamp(absdiff.r + absdiff.g + absdiff.b, 0.0, 1.0);
+}
+
+float get_damage(vec2 coord)
+{
+	float x_off = 2.0 / v_width;
+	float y_off = 2.0 / v_height;
+
+	float ix = v_width * (1.0 + coord.x) * 2.0;
+	float iy = v_height * (1.0 + coord.y) * 2.0;
+
+	float x_start = mod(ix, 32.0) / v_width / 2.0;
+	float y_start = mod(iy, 32.0) / v_height / 2.0;
+
+	float color = 0.0;
+	for (float y = 0.0; y < 32.0; y += 1.0)
+		for (float x = 0.0; x < 32.0; x += 1.0) {
+			color += get_pixel_damage(vec2(coord.x - x_start + x * x_off,
+						       coord.y - y_start + y * y_off));
+		}
+
+	return clamp(color, 0.0, 1.0);
+}
+
+void main()
+{
+	float color = get_damage(v_texture);
+	gl_FragColor = vec4(color, color, color, 1.0);
+}

shaders/texture-damage-vertex.glsl

@@ -0,0 +1,15 @@
+attribute vec2 pos;
+attribute vec2 texture;
+attribute float width;
+attribute float height;
+
+varying vec2 v_texture;
+varying float v_width;
+varying float v_height;
+
+void main() {
+	v_texture = texture;
+	v_width = width;
+	v_height = height;
+	gl_Position = vec4(pos, 0, 1);
+}

shaders/texture-fragment.glsl

@@ -0,0 +1,10 @@
+precision mediump float;
+
+uniform sampler2D u_tex;
+
+varying vec2 v_texture;
+
+void main()
+{
+	gl_FragColor = texture2D(u_tex, v_texture);
+}

shaders/texture-vertex.glsl

@@ -0,0 +1,10 @@
+attribute vec2 pos;
+attribute vec2 texture;
+
+varying vec2 v_texture;
+
+void main()
+{
+	v_texture = texture;
+	gl_Position = vec4(pos, 0, 1);
+}

src/render.c

@@ -33,6 +33,13 @@
 
 #define MAYBE_UNUSED __attribute__((unused))
 
+enum {
+	ATTR_INDEX_POS = 0,
+	ATTR_INDEX_TEXTURE,
+	ATTR_INDEX_WIDTH,
+	ATTR_INDEX_HEIGHT,
+};
+
 #define XSTR(s) STR(s)
 #define STR(s) #s
 
@@ -158,52 +165,74 @@ static int gl_load_shader(GLuint* dst, const char* source, GLenum type)
 	return 0;
 }
 
-static const char dmabuf_vertex_src[] =
-"attribute vec2 pos;\n"
-"attribute vec2 texture;\n"
-"varying vec2 v_texture;\n"
-"void main() {\n"
-"    v_texture = vec2(texture.s, 1.0 - texture.t);\n"
-"    gl_Position = vec4(pos, 0, 1);\n"
-"}\n";
-
-static const char dmabuf_fragment_src[] =
-"#extension GL_OES_EGL_image_external: require\n\n"
-"precision mediump float;\n"
-"uniform samplerExternalOES u_tex;\n"
-"varying vec2 v_texture;\n"
-"void main() {\n"
-"    gl_FragColor = texture2D(u_tex, v_texture);\n"
-"}\n";
-
-static const char texture_vertex_src[] =
-"attribute vec2 pos;\n"
-"attribute vec2 texture;\n"
-"varying vec2 v_texture;\n"
-"void main() {\n"
-"    v_texture = texture;\n"
-"    gl_Position = vec4(pos, 0, 1);\n"
-"}\n";
-
-static const char texture_fragment_src[] =
-"precision mediump float;\n"
-"uniform sampler2D u_tex;\n"
-"varying vec2 v_texture;\n"
-"void main() {\n"
-"    gl_FragColor = texture2D(u_tex, v_texture);\n"
-"}\n";
-
-static int gl_compile_shader_program(GLuint* dst, const char* vertex_src,
-				     const char* fragment_src)
+static char* read_file(const char* path)
 {
+	FILE* stream = fopen(path, "r");
+	if (!stream)
+		return NULL;
 
+	size_t size = 4096;
+	size_t rsize = 0;
+
+	char* contents = malloc(size);
+	if (!contents)
+		goto alloc_failure;
+
+	while (1) {
+		rsize += fread(contents + rsize, 1, size - rsize, stream);
+		if (rsize < size)
+			break;
+
+		size *= 2;
+		contents = realloc(contents, size);
+		if (!contents)
+			goto read_failure;
+	}
+
+	if (ferror(stream))
+		goto read_failure;
+
+	if (rsize == size) {
+		contents = realloc(contents, size + 1);
+		if (!contents)
+			goto read_failure;
+	}
+
+	contents[rsize] = '\0';
+
+	fclose(stream);
+	return contents;
+
+read_failure:
+	free(contents);
+alloc_failure:
+	fclose(stream);
+	return NULL;
+}
+
+static int gl_load_shader_from_file(GLuint* dst, const char* path, GLenum type)
+{
+	char* source = read_file(path);
+	if (!source)
+		return -1;
+
+	int rc = gl_load_shader(dst, source, type);
+
+	free(source);
+	return rc;
+}
+
+static int gl_compile_shader_program(GLuint* dst, const char* vertex_path,
+				     const char* fragment_path)
+{
 	int rc = -1;
 	GLuint vertex, fragment;
 
-	if (gl_load_shader(&vertex, vertex_src, GL_VERTEX_SHADER) < 0)
+	if (gl_load_shader_from_file(&vertex, vertex_path, GL_VERTEX_SHADER) < 0)
 		return -1;
 
-	if (gl_load_shader(&fragment, fragment_src, GL_FRAGMENT_SHADER) < 0)
+	if (gl_load_shader_from_file(&fragment, fragment_path,
+				     GL_FRAGMENT_SHADER) < 0)
 		goto fragment_failure;
 
 	GLuint program = glCreateProgram();
@@ -211,8 +240,10 @@ static int gl_compile_shader_program(GLuint* dst, const char* vertex_src,
 	glAttachShader(program, vertex);
 	glAttachShader(program, fragment);
 
-	glBindAttribLocation(program, 0, "pos");
-	glBindAttribLocation(program, 1, "texture");
+	glBindAttribLocation(program, ATTR_INDEX_POS, "pos");
+	glBindAttribLocation(program, ATTR_INDEX_TEXTURE, "texture");
+	glBindAttribLocation(program, ATTR_INDEX_WIDTH, "width");
+	glBindAttribLocation(program, ATTR_INDEX_HEIGHT, "height");
 
 	glLinkProgram(program);
 
@@ -239,7 +270,7 @@ void gl_clear(void)
 	glClear(GL_COLOR_BUFFER_BIT);
 }
 
-void gl_render(void)
+void gl_render(struct renderer* self)
 {
 	static const GLfloat s_vertices[4][2] = {
 		{ -1.0, 1.0 },
@@ -257,8 +288,13 @@ void gl_render(void)
 
 	gl_clear();
 
-	glVertexAttribPointer (0, 2, GL_FLOAT, GL_FALSE, 0, s_vertices);
-	glVertexAttribPointer (1, 2, GL_FLOAT, GL_FALSE, 0, s_positions);
+	glVertexAttribPointer(ATTR_INDEX_POS, 2, GL_FLOAT, GL_FALSE, 0,
+			      s_vertices);
+	glVertexAttribPointer(ATTR_INDEX_TEXTURE, 2, GL_FLOAT, GL_FALSE, 0,
+			      s_positions);
+
+	glVertexAttrib1f(ATTR_INDEX_WIDTH, self->width);
+	glVertexAttrib1f(ATTR_INDEX_HEIGHT, self->height);
 
 	glEnableVertexAttribArray(0);
 	glEnableVertexAttribArray(1);
@@ -271,17 +307,25 @@ void gl_render(void)
 
 void renderer_destroy(struct renderer* self)
 {
+	if (self->last_texture)
+		glDeleteTextures(1, &self->last_texture);
+
 	glDeleteProgram(self->dmabuf_shader_program);
 	glDeleteProgram(self->texture_shader_program);
+	glDeleteProgram(self->damage_shader_program);
 	eglMakeCurrent(self->display, EGL_NO_SURFACE, EGL_NO_SURFACE,
 		       EGL_NO_CONTEXT);
 	eglDestroySurface(self->display, self->surface);
 	eglDestroyContext(self->display, self->context);
 	eglTerminate(self->display);
+
+	pixman_region_fini(&self->current_damage);
 }
 
 int renderer_init(struct renderer* self, uint32_t width, uint32_t height)
 {
+	pixman_region_init(&self->current_damage);
+
 	if (!eglBindAPI(EGL_OPENGL_ES_API))
 		return -1;
 
@@ -344,13 +388,18 @@ int renderer_init(struct renderer* self, uint32_t width, uint32_t height)
 		goto late_extension_failure;
 
 	if (gl_compile_shader_program(&self->dmabuf_shader_program,
-				      dmabuf_vertex_src,
-				      dmabuf_fragment_src) < 0)
+				      "shaders/dmabuf-vertex.glsl",
+				      "shaders/dmabuf-fragment.glsl") < 0)
 		goto shader_failure;
 
 	if (gl_compile_shader_program(&self->texture_shader_program,
-				      texture_vertex_src,
-				      texture_fragment_src) < 0)
+				      "shaders/texture-vertex.glsl",
+				      "shaders/texture-fragment.glsl") < 0)
+		goto shader_failure;
+
+	if (gl_compile_shader_program(&self->damage_shader_program,
+				      "shaders/texture-damage-vertex.glsl",
+				      "shaders/texture-damage-fragment.glsl") < 0)
 		goto shader_failure;
 
 	self->width = width;
@@ -427,10 +476,16 @@ int render_dmabuf_frame(struct renderer* self, struct dmabuf_frame* frame)
 	glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, image);
 
 	glUseProgram(self->dmabuf_shader_program);
-	gl_render();
+	glUniform1i(glGetUniformLocation(self->dmabuf_shader_program, "u_tex"), 0);
+
+	glViewport(0, 0, self->width, self->height);
+	gl_render(self);
+
+	if (self->last_texture)
+		glDeleteTextures(1, &self->last_texture);
+	self->last_texture = tex;
 
 	glBindTexture(GL_TEXTURE_2D, 0);
-	glDeleteTextures(1, &tex);
 	eglDestroyImageKHR(self->display, image);
 
 	return 0;
@@ -448,17 +503,29 @@ int render_framebuffer(struct renderer* self, const void* addr, uint32_t format,
 	if (gl_format_from_wl_shm(&gl_format, format) < 0)
 		return -1;
 
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
 	glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT, stride / 4);
 	glTexImage2D(GL_TEXTURE_2D, 0, self->read_format, width, height, 0,
 		     gl_format, GL_UNSIGNED_BYTE, addr);
-	glGenerateMipmap(GL_TEXTURE_2D);
 	glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT, 0);
 
+	render_check_damage(self, GL_TEXTURE_2D, tex);
+
 	glUseProgram(self->texture_shader_program);
-	gl_render();
+	glUniform1i(glGetUniformLocation(self->texture_shader_program, "u_tex"), 0);
+
+	glViewport(0, 0, self->width, self->height);
+	gl_render(self);
+
+	if (self->last_texture)
+		glDeleteTextures(1, &self->last_texture);
+	self->last_texture = tex;
 
 	glBindTexture(GL_TEXTURE_2D, 0);
-	glDeleteTextures(1, &tex);
 
 	return 0;
 }
@@ -471,3 +538,42 @@ void render_copy_pixels(struct renderer* self, void* dst, uint32_t y,
 	glReadPixels(0, y, self->width, height, self->read_format,
 		    self->read_type, dst);
 }
+
+void render_check_damage(struct renderer* self, GLenum target, GLuint tex)
+{
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(target, tex);
+
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(target, self->last_texture);
+
+	glUseProgram(self->damage_shader_program);
+
+	glUniform1i(glGetUniformLocation(self->damage_shader_program, "tex0"), 0);
+	glUniform1i(glGetUniformLocation(self->damage_shader_program, "tex1"), 1);
+
+	int width = self->width / 32;
+	int height = self->height / 32;
+
+	uint32_t* buffer = malloc(width * height * 4);
+	if (!buffer)
+		return;
+
+	glViewport(0, 0, width, height);
+	gl_render(self);
+
+	glReadPixels(0, 0, width, height, self->read_format, self->read_type,
+		     buffer);
+
+	struct pixman_region16* damage = &self->current_damage;
+	pixman_region_clear(damage);
+
+	for (int y = 0; y < height; ++y)
+		for (int x = 0; x < width; ++x)
+			if (buffer[y * width + x] & 0xff00)
+				pixman_region_union_rect(damage, damage,
+							 x * 32, y * 32,
+							 32, 32);
+
+	free(buffer);
+}