Pass rect and matrix by value in geometry functions.

Several things irk me about passing values as const pointers:

* They can be NULL, which is not a valid value.
* They require explicit temporary variables for storage.
* They don't compose easily in a legible manner, requiring
  weird pointer passing semantics where the variable being assigned
  is hidden as an argument in the innermost function call.
* We can't change the value through the pointer, requiring yet more
  local variables to hold copies of the input value.

In the device interface where we pass a matrix to a function, we often
find ourselves making a local copy of the matrix so we can concatenate
other transforms to it. This copying is a lot of unnecessary busywork
that I hope to eventually avoid by laying the groundwork with this
commit.

This is a rather large API change, so I apologize for the inconvenience,
but I hope the end result and gain in legibility will be worth the pain.

5 files changed, 56 insertions, 70 deletions

diff --git a/platform/gl/gl-annotate.c b/platform/gl/gl-annotate.c
index 92458824..dca7519a 100644
--- a/platform/gl/gl-annotate.c
+++ b/platform/gl/gl-annotate.c
@@ -115,7 +115,7 @@ static void new_annot(int type)
 	case PDF_ANNOT_SOUND:
 		{
 			fz_rect icon_rect = { 12, 12, 12+20, 12+20 };
-			pdf_set_annot_rect(ctx, selected_annot, &icon_rect);
+			pdf_set_annot_rect(ctx, selected_annot, icon_rect);
 			pdf_set_annot_color(ctx, selected_annot, 3, yellow);
 		}
 		break;
@@ -123,7 +123,7 @@ static void new_annot(int type)
 	case PDF_ANNOT_FREE_TEXT:
 		{
 			fz_rect text_rect = { 12, 12, 12+200, 12+100 };
-			pdf_set_annot_rect(ctx, selected_annot, &text_rect);
+			pdf_set_annot_rect(ctx, selected_annot, text_rect);
 			pdf_set_annot_border(ctx, selected_annot, 0);
 			pdf_set_annot_default_appearance(ctx, selected_annot, "Helv", 12, black);
 		}
@@ -132,7 +132,7 @@ static void new_annot(int type)
 	case PDF_ANNOT_STAMP:
 		{
 			fz_rect stamp_rect = { 12, 12, 12+190, 12+50 };
-			pdf_set_annot_rect(ctx, selected_annot, &stamp_rect);
+			pdf_set_annot_rect(ctx, selected_annot, stamp_rect);
 			pdf_set_annot_color(ctx, selected_annot, 3, red);
 		}
 		break;
@@ -140,7 +140,7 @@ static void new_annot(int type)
 	case PDF_ANNOT_CARET:
 		{
 			fz_rect caret_rect = { 12, 12, 12+18, 12+15 };
-			pdf_set_annot_rect(ctx, selected_annot, &caret_rect);
+			pdf_set_annot_rect(ctx, selected_annot, caret_rect);
 			pdf_set_annot_color(ctx, selected_annot, 3, blue);
 		}
 		break;
@@ -158,7 +158,7 @@ static void new_annot(int type)
 	case PDF_ANNOT_CIRCLE:
 		{
 			fz_rect shape_rect = { 12, 12, 12+100, 12+50 };
-			pdf_set_annot_rect(ctx, selected_annot, &shape_rect);
+			pdf_set_annot_rect(ctx, selected_annot, shape_rect);
 			pdf_set_annot_border(ctx, selected_annot, 1);
 			pdf_set_annot_color(ctx, selected_annot, 3, red);
 		}
@@ -553,8 +553,8 @@ void do_annotate_panel(void)
 
 		/* common annotation properties */
 
-		pdf_annot_rect(ctx, selected_annot, &rect);
-		fz_irect_from_rect(&irect, &rect);
+		rect = pdf_annot_rect(ctx, selected_annot);
+		irect = fz_irect_from_rect(rect);
 		ui_label("Rect: %d %d %d %d", irect.x0, irect.y0, irect.x1, irect.y1);
 
 		do_annotate_flags();
@@ -778,9 +778,8 @@ static void do_edit_icon(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 			moving = 0;
 			if (fz_abs(start_pt.x - rect->x0) > 0.1f || fz_abs(start_pt.x - rect->y0) > 0.1f)
 			{
-				fz_rect trect = *rect;
-				fz_transform_rect(&trect, &view_page_inv_ctm);
-				pdf_set_annot_rect(ctx, selected_annot, &trect);
+				fz_rect trect = fz_transform_rect(*rect, view_page_inv_ctm);
+				pdf_set_annot_rect(ctx, selected_annot, trect);
 			}
 		}
 	}
@@ -800,7 +799,7 @@ static void do_edit_rect(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 	static fz_rect start_rect;
 	static int state = ER_NONE;
 
-	fz_expand_irect(&area, 5);
+	area = fz_expand_irect(area, 5);
 	if (ui_mouse_inside(&canvas_area) && ui_mouse_inside(&area))
 	{
 		ui.hot = selected_annot;
@@ -839,9 +838,8 @@ static void do_edit_rect(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 			state = ER_NONE;
 			if (rects_differ(&start_rect, rect, 1))
 			{
-				fz_rect trect = *rect;
-				fz_transform_rect(&trect, &view_page_inv_ctm);
-				pdf_set_annot_rect(ctx, selected_annot, &trect);
+				fz_rect trect = fz_transform_rect(*rect, view_page_inv_ctm);
+				pdf_set_annot_rect(ctx, selected_annot, trect);
 			}
 		}
 	}
@@ -856,7 +854,7 @@ static void do_edit_line(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 	fz_point a, b;
 	float lw;
 
-	fz_expand_irect(&area, 5);
+	area = fz_expand_irect(area, 5);
 	if (ui_mouse_inside(&canvas_area) && ui_mouse_inside(&area))
 	{
 		ui.hot = selected_annot;
@@ -864,12 +862,12 @@ static void do_edit_line(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 		{
 			ui.active = selected_annot;
 			pdf_annot_line(ctx, selected_annot, &start_a, &start_b);
-			fz_transform_point(&start_a, &view_page_ctm);
-			fz_transform_point(&start_b, &view_page_ctm);
+			start_a = fz_transform_point(start_a, view_page_ctm);
+			start_b = fz_transform_point(start_b, view_page_ctm);
 			a_grab = fz_make_irect(start_a.x, start_a.y, start_a.x, start_a.y);
 			b_grab = fz_make_irect(start_b.x, start_b.y, start_b.x, start_b.y);
-			fz_expand_irect(&a_grab, 10);
-			fz_expand_irect(&b_grab, 10);
+			a_grab = fz_expand_irect(a_grab, 10);
+			b_grab = fz_expand_irect(b_grab, 10);
 			state = EL_NONE;
 			if (ui_mouse_inside(&a_grab)) state |= EL_A;
 			if (ui_mouse_inside(&b_grab)) state |= EL_B;
@@ -895,7 +893,7 @@ static void do_edit_line(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 		rect->x1 = fz_max(a.x, b.x);
 		rect->y1 = fz_max(a.y, b.y);
 		lw = pdf_annot_border(ctx, selected_annot);
-		fz_expand_rect(rect, fz_matrix_expansion(&view_page_ctm) * lw);
+		*rect = fz_expand_rect(*rect, fz_matrix_expansion(view_page_ctm) * lw);
 
 		/* cancel on right click */
 		if (ui.right)
@@ -907,8 +905,8 @@ static void do_edit_line(fz_irect canvas_area, fz_irect area, fz_rect *rect)
 			state = EL_NONE;
 			if (points_differ(&start_a, &a, 1) || points_differ(&start_b, &b, 1))
 			{
-				fz_transform_point(&a, &view_page_inv_ctm);
-				fz_transform_point(&b, &view_page_inv_ctm);
+				a = fz_transform_point(a, view_page_inv_ctm);
+				b = fz_transform_point(b, view_page_inv_ctm);
 				pdf_set_annot_line(ctx, selected_annot, a, b);
 			}
 		}
@@ -938,11 +936,11 @@ static void do_edit_polygon(fz_irect canvas_area, int close)
 		if (n > 0)
 		{
 			p = pdf_annot_vertex(ctx, selected_annot, n-1);
-			fz_transform_point(&p, &view_page_ctm);
+			p = fz_transform_point(p, view_page_ctm);
 			if (close)
 			{
 				a = pdf_annot_vertex(ctx, selected_annot, 0);
-				fz_transform_point(&a, &view_page_ctm);
+				a = fz_transform_point(a, view_page_ctm);
 			}
 			glBegin(GL_LINE_STRIP);
 			glColor4f(1, 0, 0, 1);
@@ -966,8 +964,7 @@ static void do_edit_polygon(fz_irect canvas_area, int close)
 		/* commit point on mouse-up */
 		if (!ui.down)
 		{
-			fz_point p = { ui.x, ui.y };
-			fz_transform_point(&p, &view_page_inv_ctm);
+			fz_point p = fz_transform_point_xy(ui.x, ui.y, view_page_inv_ctm);
 			pdf_add_annot_vertex(ctx, selected_annot, p);
 			drawing = 0;
 		}
@@ -1029,7 +1026,7 @@ static void do_edit_ink(fz_irect canvas_area)
 			if (n > 1)
 			{
 				for (i = 0; i < n; ++i)
-					fz_transform_point(&p[i], &view_page_inv_ctm);
+					p[i] = fz_transform_point(p[i], view_page_inv_ctm);
 				pdf_add_annot_ink_list(ctx, selected_annot, n, p);
 			}
 			drawing = 0;
@@ -1064,8 +1061,8 @@ static void do_edit_quad_points(void)
 		fz_point page_a = { pt.x, pt.y };
 		fz_point page_b = { ui.x, ui.y };
 
-		fz_transform_point(&page_a, &view_page_inv_ctm);
-		fz_transform_point(&page_b, &view_page_inv_ctm);
+		page_a = fz_transform_point(page_a, view_page_inv_ctm);
+		page_b = fz_transform_point(page_b, view_page_inv_ctm);
 
 		n = fz_highlight_selection(ctx, page_text, page_a, page_b, hits, nelem(hits));
 
@@ -1076,8 +1073,7 @@ static void do_edit_quad_points(void)
 		glBegin(GL_QUADS);
 		for (i = 0; i < n; ++i)
 		{
-			fz_quad thit = hits[i];
-			fz_transform_quad(&thit, &view_page_ctm);
+			fz_quad thit = fz_transform_quad(hits[i], view_page_ctm);
 			glVertex2f(thit.ul.x, thit.ul.y);
 			glVertex2f(thit.ur.x, thit.ur.y);
 			glVertex2f(thit.lr.x, thit.lr.y);
@@ -1114,9 +1110,9 @@ void do_annotate_canvas(fz_irect canvas_area)
 
 	for (annot = pdf_first_annot(ctx, page); annot; annot = pdf_next_annot(ctx, annot))
 	{
-		pdf_bound_annot(ctx, annot, &bounds);
-		fz_transform_rect(&bounds, &view_page_ctm);
-		fz_irect_from_rect(&area, &bounds);
+		bounds = pdf_bound_annot(ctx, annot);
+		bounds = fz_transform_rect(bounds, view_page_ctm);
+		area = fz_irect_from_rect(bounds);
 
 		if (ui_mouse_inside(&canvas_area) && ui_mouse_inside(&area))
 		{
@@ -1189,7 +1185,7 @@ void do_annotate_canvas(fz_irect canvas_area)
 			glEnable(GL_BLEND);
 			glColor4f(1, 1, 1, 1);
 			glBegin(GL_LINE_LOOP);
-			fz_irect_from_rect(&area, &bounds);
+			area = fz_irect_from_rect(bounds);
 			glVertex2f(area.x0-0.5f, area.y0-0.5f);
 			glVertex2f(area.x1+0.5f, area.y0-0.5f);
 			glVertex2f(area.x1+0.5f, area.y1+0.5f);
diff --git a/platform/gl/gl-font.c b/platform/gl/gl-font.c
index 08dd773a..8a331b3e 100644
--- a/platform/gl/gl-font.c
+++ b/platform/gl/gl-font.c
@@ -137,7 +137,7 @@ static struct glyph *lookup_glyph(fz_font *font, int gid, float *xp, float *yp)
 	int w, h;
 
 	/* match fitz's glyph cache quantization */
-	fz_scale(&trm, g_font_size, -g_font_size);
+	trm = fz_scale(g_font_size, -g_font_size);
 	trm.e = *xp;
 	trm.f = *yp;
 	fz_subpixel_adjust(ctx, &trm, &subpix_trm, &subx, &suby);
diff --git a/platform/gl/gl-input.c b/platform/gl/gl-input.c
index 56fcf74d..c3898f50 100644
--- a/platform/gl/gl-input.c
+++ b/platform/gl/gl-input.c
@@ -409,7 +409,7 @@ int ui_input(struct input *input, int width, int height)
 
 	area = ui_pack(width, ui.lineheight * height + 6);
 	ui_draw_bevel_rect(area, UI_COLOR_TEXT_BG, 1);
-	fz_expand_irect(&area, -2);
+	area = fz_expand_irect(area, -2);
 
 	if (height > 1)
 		area.x1 -= ui.lineheight;
diff --git a/platform/gl/gl-main.c b/platform/gl/gl-main.c
index 899dc4ec..5b26a48f 100644
--- a/platform/gl/gl-main.c
+++ b/platform/gl/gl-main.c
@@ -207,20 +207,18 @@ void update_title(void)
 
 void transform_page(void)
 {
-	fz_rect rect = page_bounds;
+	fz_rect rect;
 	fz_matrix matrix;
 
-	draw_page_bounds = page_bounds;
-
-	fz_scale(&draw_page_ctm, currentzoom / 72, currentzoom / 72);
-	fz_pre_rotate(&draw_page_ctm, -currentrotate);
+	draw_page_ctm = fz_scale(currentzoom / 72, currentzoom / 72);
+	draw_page_ctm = fz_pre_rotate(draw_page_ctm, -currentrotate);
 
 	/* fix the page origin at 0,0 after rotation */
-	fz_transform_rect(&rect, &draw_page_ctm);
-	fz_translate(&matrix, -rect.x0, -rect.y0);
-	fz_concat(&draw_page_ctm, &draw_page_ctm, &matrix);
+	rect = fz_transform_rect(page_bounds, draw_page_ctm);
+	matrix = fz_translate(-rect.x0, -rect.y0);
+	draw_page_ctm = fz_concat(draw_page_ctm, matrix);
 
-	fz_transform_rect(&draw_page_bounds, &draw_page_ctm);
+	draw_page_bounds = fz_transform_rect(page_bounds, draw_page_ctm);
 }
 
 void load_page(void)
@@ -245,10 +243,10 @@ void load_page(void)
 	page_text = fz_new_stext_page_from_page(ctx, fzpage, NULL);
 
 	/* compute bounds here for initial window size */
-	fz_bound_page(ctx, fzpage, &page_bounds);
+	page_bounds = fz_bound_page(ctx, fzpage);
 	transform_page();
 
-	fz_irect_from_rect(&area, &draw_page_bounds);
+	area = fz_irect_from_rect(draw_page_bounds);
 	page_tex.w = area.x1 - area.x0;
 	page_tex.h = area.y1 - area.y0;
 }
@@ -281,16 +279,14 @@ static struct mark save_mark()
 {
 	struct mark mark;
 	mark.page = currentpage;
-	mark.scroll.x = scroll_x;
-	mark.scroll.y = scroll_y;
-	fz_transform_point(&mark.scroll, &view_page_inv_ctm);
+	mark.scroll = fz_transform_point_xy(scroll_x, scroll_y, view_page_inv_ctm);
 	return mark;
 }
 
 static void restore_mark(struct mark mark)
 {
 	currentpage = mark.page;
-	fz_transform_point(&mark.scroll, &draw_page_ctm);
+	mark.scroll = fz_transform_point(mark.scroll, draw_page_ctm);
 	scroll_x = mark.scroll.x;
 	scroll_y = mark.scroll.y;
 }
@@ -337,9 +333,8 @@ static void jump_to_page(int newpage)
 
 static void jump_to_page_xy(int newpage, float x, float y)
 {
-	fz_point p = { x, y };
+	fz_point p = fz_transform_point_xy(x, y, draw_page_ctm);
 	newpage = fz_clampi(newpage, 0, fz_count_pages(ctx, doc) - 1);
-	fz_transform_point(&p, &draw_page_ctm);
 	clear_future();
 	push_history();
 	currentpage = newpage;
@@ -427,8 +422,8 @@ static void do_links(fz_link *link)
 	while (link)
 	{
 		bounds = link->rect;
-		fz_transform_rect(&bounds, &view_page_ctm);
-		fz_irect_from_rect(&area, &bounds);
+		bounds = fz_transform_rect(link->rect, view_page_ctm);
+		area = fz_irect_from_rect(bounds);
 
 		if (ui_mouse_inside(&area))
 		{
@@ -493,8 +488,8 @@ static void do_page_selection(void)
 		fz_point page_a = { pt.x, pt.y };
 		fz_point page_b = { ui.x, ui.y };
 
-		fz_transform_point(&page_a, &view_page_inv_ctm);
-		fz_transform_point(&page_b, &view_page_inv_ctm);
+		page_a = fz_transform_point(page_a, view_page_inv_ctm);
+		page_b = fz_transform_point(page_b, view_page_inv_ctm);
 
 		if (ui.mod == GLUT_ACTIVE_CTRL)
 			fz_snap_selection(ctx, page_text, &page_a, &page_b, FZ_SELECT_WORDS);
@@ -510,8 +505,7 @@ static void do_page_selection(void)
 		glBegin(GL_QUADS);
 		for (i = 0; i < n; ++i)
 		{
-			fz_quad thit = hits[i];
-			fz_transform_quad(&thit, &view_page_ctm);
+			fz_quad thit = fz_transform_quad(hits[i], view_page_ctm);
 			glVertex2f(thit.ul.x, thit.ul.y);
 			glVertex2f(thit.ur.x, thit.ur.y);
 			glVertex2f(thit.lr.x, thit.lr.y);
@@ -546,8 +540,7 @@ static void do_search_hits(void)
 	glBegin(GL_QUADS);
 	for (i = 0; i < search_hit_count; ++i)
 	{
-		fz_quad thit = search_hit_quads[i];
-		fz_transform_quad(&thit, &view_page_ctm);
+		fz_quad thit = fz_transform_quad(search_hit_quads[i], view_page_ctm);
 		glVertex2f(thit.ul.x, thit.ul.y);
 		glVertex2f(thit.ur.x, thit.ur.y);
 		glVertex2f(thit.lr.x, thit.lr.y);
@@ -567,9 +560,7 @@ static void do_forms(void)
 	if (!pdf || search_active)
 		return;
 
-	p.x = ui.x;
-	p.y = ui.y;
-	fz_transform_point(&p, &view_page_inv_ctm);
+	p = fz_transform_point_xy(ui.x, ui.y, view_page_inv_ctm);
 
 	if (ui.down && !ui.active)
 	{
@@ -1131,10 +1122,9 @@ static void do_canvas(void)
 	view_page_ctm = draw_page_ctm;
 	view_page_ctm.e += page_x;
 	view_page_ctm.f += page_y;
-	fz_invert_matrix(&view_page_inv_ctm, &view_page_ctm);
-	view_page_bounds = page_bounds;
-	fz_transform_rect(&view_page_bounds, &view_page_ctm);
-	fz_irect_from_rect(&view_page_area, &view_page_bounds);
+	view_page_inv_ctm = fz_invert_matrix(view_page_ctm);
+	view_page_bounds = fz_transform_rect(page_bounds, view_page_ctm);
+	view_page_area = fz_irect_from_rect(view_page_bounds);
 
 	ui_draw_image(&page_tex, page_x, page_y);
 
diff --git a/platform/gl/gl-ui.c b/platform/gl/gl-ui.c
index 2d8fd5be..9539af7b 100644
--- a/platform/gl/gl-ui.c
+++ b/platform/gl/gl-ui.c
@@ -687,7 +687,7 @@ void ui_dialog_begin(int w, int h)
 	y = (ui.window_h-h)/3;
 	area = fz_make_irect(x, y, x+w, y+h);
 	ui_draw_bevel_rect(area, UI_COLOR_PANEL, 0);
-	fz_expand_irect(&area, -14);
+	area = fz_expand_irect(area, -14);
 	ui_pack_push(area);
 }