module fortplot_raster_labels !! Raster axis labels (title, xlabel, ylabel) rendering functionality !! Extracted from fortplot_raster_axes.f90 for single responsibility principle use fortplot_constants, only: XLABEL_VERTICAL_OFFSET, TICK_MARK_LENGTH, & YLABEL_EXTRA_GAP, TITLE_VERTICAL_OFFSET use fortplot_text_rendering, only: render_text_to_image, calculate_text_width, & calculate_text_height, & calculate_text_descent, & calculate_text_width_with_size, & render_text_with_size, TITLE_FONT_SIZE use fortplot_text_fonts, only: get_font_ascent_ratio use fortplot_latex_parser, only: process_latex_in_text use fortplot_unicode, only: escape_unicode_for_raster use fortplot_text_helpers, only: prepare_mathtext_if_needed use fortplot_margins, only: plot_area_t use fortplot_raster_core, only: raster_image_t use fortplot_bitmap, only: render_text_to_bitmap, rotate_bitmap_90_ccw, & rotate_bitmap_90_cw, composite_bitmap_to_raster use fortplot_raster_ticks, only: last_y_tick_max_width, & last_y_tick_max_width_right, & last_x_tick_max_height_top, & Y_TICK_LABEL_RIGHT_PAD, & Y_TICK_LABEL_LEFT_PAD, X_TICK_LABEL_TOP_PAD use, intrinsic :: iso_fortran_env, only: wp => real64 implicit none private public :: raster_draw_axis_labels public :: raster_render_ylabel public :: raster_render_ylabel_right public :: raster_draw_top_xlabel public :: render_title_centered public :: render_title_centered_with_size public :: compute_title_position public :: compute_ylabel_x_pos public :: y_tick_label_right_edge_at_axis contains subroutine raster_draw_axis_labels(raster, width, height, plot_area, title, & xlabel, ylabel) !! Draw all axis labels (title, xlabel, ylabel) type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: title, xlabel, ylabel character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: label_x, label_y, processed_len, math_len integer :: label_width, label_height ! Title at top if (len_trim(title) > 0) then call render_title_centered(raster, width, height, plot_area, title) end if ! X label at bottom if (len_trim(xlabel) > 0) then call process_latex_in_text(trim(xlabel), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) label_width = calculate_text_width(trim(escaped_text)) label_height = calculate_text_height(trim(escaped_text)) label_x = plot_area%left + plot_area%width/2 - label_width/2 ! Move xlabel 5 pixels down (increase Y in PNG coordinates) label_y = min(height - label_height - 5, plot_area%bottom + & plot_area%height + XLABEL_VERTICAL_OFFSET + 5) call render_text_to_image(raster%image_data, width, height, & label_x, label_y, & trim(escaped_text), 0_1, 0_1, 0_1) end if ! Y label at left if (len_trim(ylabel) > 0) then call raster_render_ylabel(raster, width, height, plot_area, ylabel) end if end subroutine raster_draw_axis_labels subroutine raster_render_ylabel(raster, width, height, plot_area, ylabel) !! Render rotated ylabel to the left of y-axis type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: ylabel character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: processed_len, math_len integer(1), allocatable :: text_bitmap(:, :, :), rotated_bitmap(:, :, :) integer :: text_width, text_height, text_descent integer :: rotated_width, rotated_height integer :: target_x, target_y integer :: y_tick_label_edge if (len_trim(ylabel) == 0) return ! Process LaTeX call process_latex_in_text(trim(ylabel), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) ! Calculate text dimensions text_width = calculate_text_width(trim(escaped_text)) text_height = calculate_text_height(trim(escaped_text)) text_descent = calculate_text_descent(trim(escaped_text)) ! Allocate text bitmap allocate (text_bitmap(text_width, text_height, 3)) text_bitmap = -1_1 ! Initialize to white ! Render text to bitmap (upright). ! Position baseline to leave room for descenders. call render_text_to_bitmap(text_bitmap, text_width, text_height, 0, & text_height - text_descent, & trim(escaped_text)) ! Rotate 90 degrees counter-clockwise rotated_width = text_height rotated_height = text_width allocate (rotated_bitmap(rotated_width, rotated_height, 3)) call rotate_bitmap_90_ccw(text_bitmap, rotated_bitmap, text_width, text_height) ! Compute the rightmost edge of y-tick labels y_tick_label_edge = y_tick_label_right_edge_at_axis(plot_area, & last_y_tick_max_width) ! Compute ylabel position with dynamic gap target_x = compute_ylabel_x_pos(y_tick_label_edge, rotated_width, plot_area) ! Center vertically in plot area target_y = plot_area%bottom + plot_area%height/2 - rotated_height/2 ! Composite to raster call composite_bitmap_to_raster(raster%image_data, width, height, & rotated_bitmap, & rotated_width, rotated_height, & target_x, target_y) deallocate (text_bitmap, rotated_bitmap) end subroutine raster_render_ylabel integer function y_tick_label_left_edge_at_axis(plot_area, max_width_measured) !! Compute the leftmost edge of right-side y-tick labels relative to the axis type(plot_area_t), intent(in) :: plot_area integer, intent(in) :: max_width_measured y_tick_label_left_edge_at_axis = plot_area%left + plot_area%width + & TICK_MARK_LENGTH + Y_TICK_LABEL_LEFT_PAD end function y_tick_label_left_edge_at_axis integer function compute_ylabel_right_x_pos(y_tick_label_edge, rotated_width, & plot_area, canvas_width) !! Compute x-position for right-side ylabel avoiding overlap with tick labels integer, intent(in) :: y_tick_label_edge integer, intent(in) :: rotated_width type(plot_area_t), intent(in) :: plot_area integer, intent(in) :: canvas_width compute_ylabel_right_x_pos = y_tick_label_edge + YLABEL_EXTRA_GAP if (compute_ylabel_right_x_pos + rotated_width > canvas_width - 15) then compute_ylabel_right_x_pos = max(plot_area%left + plot_area%width + 5, & canvas_width - rotated_width - 15) end if end function compute_ylabel_right_x_pos subroutine raster_render_ylabel_right(raster, width, height, plot_area, ylabel) !! Render rotated ylabel along the right side of the axis type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: ylabel character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: processed_len, math_len integer(1), allocatable :: text_bitmap(:, :, :), rotated_bitmap(:, :, :) integer :: text_width, text_height, text_descent integer :: rotated_width, rotated_height integer :: target_x, target_y integer :: y_tick_label_edge if (len_trim(ylabel) == 0) return call process_latex_in_text(trim(ylabel), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) text_width = calculate_text_width(trim(escaped_text)) text_height = calculate_text_height(trim(escaped_text)) text_descent = calculate_text_descent(trim(escaped_text)) allocate (text_bitmap(text_width, text_height, 3)) text_bitmap = -1_1 call render_text_to_bitmap(text_bitmap, text_width, text_height, 0, & text_height - text_descent, & trim(escaped_text)) rotated_width = text_height rotated_height = text_width allocate (rotated_bitmap(rotated_width, rotated_height, 3)) call rotate_bitmap_90_cw(text_bitmap, rotated_bitmap, text_width, text_height) y_tick_label_edge = y_tick_label_left_edge_at_axis(plot_area, & last_y_tick_max_width_right) target_x = compute_ylabel_right_x_pos(y_tick_label_edge, rotated_width, & plot_area, width) target_y = plot_area%bottom + plot_area%height/2 - rotated_height/2 call composite_bitmap_to_raster(raster%image_data, width, height, & rotated_bitmap, & rotated_width, rotated_height, & target_x, target_y) deallocate (text_bitmap, rotated_bitmap) end subroutine raster_render_ylabel_right integer function y_tick_label_right_edge_at_axis(plot_area, max_width_measured) !! Compute the rightmost edge of y-tick labels relative to the y-axis type(plot_area_t), intent(in) :: plot_area integer, intent(in) :: max_width_measured ! Return an edge that accounts for the maximum tick label width so ylabel ! placement can reliably clear tick labels (matplotlib-like clearance). y_tick_label_right_edge_at_axis = plot_area%left - TICK_MARK_LENGTH - & Y_TICK_LABEL_RIGHT_PAD - & max(0, max_width_measured) end function y_tick_label_right_edge_at_axis integer function compute_ylabel_x_pos(y_tick_label_edge, rotated_width, plot_area) !! Compute x-position for ylabel to avoid overlapping with y-tick labels integer, intent(in) :: y_tick_label_edge integer, intent(in) :: rotated_width type(plot_area_t), intent(in) :: plot_area integer :: min_left_margin integer :: ideal_x integer :: safe_x associate (unused_plot_area => plot_area); end associate min_left_margin = max(15, rotated_width/4) ! y_tick_label_edge represents the left boundary of the y-tick label ! block (right edge minus maximum tick label width). Place the ylabel ! entirely to the left of that boundary. ideal_x = y_tick_label_edge - YLABEL_EXTRA_GAP - rotated_width ! If tick labels are already off-canvas, favor keeping the label visible. if (y_tick_label_edge <= 0) then compute_ylabel_x_pos = max(min_left_margin, ideal_x) return end if if (ideal_x >= min_left_margin) then compute_ylabel_x_pos = ideal_x return end if ! If there is not enough room to keep both a minimum margin and the ! extra gap, drop the extra gap first; if still no room, allow the ! ylabel to extend off-canvas to avoid overlapping tick labels. safe_x = y_tick_label_edge - rotated_width - 1 if (safe_x >= min_left_margin) then compute_ylabel_x_pos = min_left_margin else compute_ylabel_x_pos = safe_x end if end function compute_ylabel_x_pos integer function compute_top_xlabel_y_pos(plot_area, label_height) !! Compute y-position for an x-label rendered above the axis type(plot_area_t), intent(in) :: plot_area integer, intent(in) :: label_height compute_top_xlabel_y_pos = max(1, plot_area%bottom - X_TICK_LABEL_TOP_PAD - & last_x_tick_max_height_top - label_height - 5) end function compute_top_xlabel_y_pos subroutine raster_draw_top_xlabel(raster, width, height, plot_area, xlabel) !! Render an xlabel centered above the plot area type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: xlabel character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: processed_len, math_len integer :: label_width, label_height integer :: label_x, label_y if (len_trim(xlabel) == 0) return call process_latex_in_text(trim(xlabel), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) label_width = calculate_text_width(trim(escaped_text)) label_height = calculate_text_height(trim(escaped_text)) if (label_height <= 0) label_height = 12 label_x = plot_area%left + plot_area%width/2 - label_width/2 label_y = compute_top_xlabel_y_pos(plot_area, label_height) call render_text_to_image(raster%image_data, width, height, label_x, label_y, & trim(escaped_text), 0_1, 0_1, 0_1) end subroutine raster_draw_top_xlabel subroutine render_title_centered(raster, width, height, plot_area, title_text) !! Render title centered above the plot area type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: title_text character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: processed_len, math_len integer :: title_px, title_py real(wp) :: title_px_real, title_py_real if (len_trim(title_text) == 0) return call compute_title_position(plot_area, title_text, processed_text, & processed_len, & escaped_text, title_px_real, title_py_real) title_px = int(title_px_real) title_py = int(title_py_real) ! Render title with larger font size call render_text_with_size(raster%image_data, width, height, title_px, & title_py, & trim(escaped_text), 0_1, 0_1, 0_1, & real(TITLE_FONT_SIZE, wp)) end subroutine render_title_centered subroutine compute_title_position(plot_area, title_text, processed_text, & processed_len, escaped_text, title_px, title_py) !! Compute the position for centered title above plot area type(plot_area_t), intent(in) :: plot_area character(len=*), intent(in) :: title_text character(len=*), intent(out) :: processed_text, escaped_text integer, intent(out) :: processed_len real(wp), intent(out) :: title_px, title_py integer :: title_width character(len=600) :: math_ready integer :: math_len call process_latex_in_text(trim(title_text), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) ! Calculate text width using the larger title font size title_width = calculate_text_width_with_size(trim(escaped_text), & real(TITLE_FONT_SIZE, wp)) ! Center the title properly over the plot area title_px = real(plot_area%left + plot_area%width/2 - title_width/2, wp) title_py = real(plot_area%bottom - TITLE_VERTICAL_OFFSET, wp) title_py = max(1.0_wp, title_py) end subroutine compute_title_position subroutine render_title_centered_with_size(raster, width, height, center_x, & title_y, title_text, font_scale) !! Render title centered at specified position with custom font scale !! Used for suptitle rendering above subplots type(raster_image_t), intent(inout) :: raster integer, intent(in) :: width, height integer, intent(in) :: center_x, title_y character(len=*), intent(in) :: title_text real(wp), intent(in) :: font_scale character(len=500) :: processed_text character(len=600) :: math_ready character(len=600) :: escaped_text integer :: processed_len, math_len integer :: title_width, title_px real(wp) :: scaled_font_size if (len_trim(title_text) == 0) return call process_latex_in_text(trim(title_text), processed_text, processed_len) call prepare_mathtext_if_needed(processed_text(1:processed_len), & math_ready, math_len) call escape_unicode_for_raster(math_ready(1:math_len), escaped_text) scaled_font_size = real(TITLE_FONT_SIZE, wp) * font_scale title_width = calculate_text_width_with_size(trim(escaped_text), & scaled_font_size) title_px = center_x - title_width / 2 call render_text_with_size(raster%image_data, width, height, title_px, & title_y, trim(escaped_text), 0_1, 0_1, 0_1, & scaled_font_size) end subroutine render_title_centered_with_size end module fortplot_raster_labels