Re: [pygame] Font height

["Brian Fisher" <brian@xxxxxxxxxxxxxxxxxxx>]

well with pygame 1.6, the only thing metric that I could get something
useful with is getting the baseline using the descent, although even
there the descent is negative, which seems odd to me.

The line heights jump around a lot from font to font, some had leading
to the top of the font, others didn't, and the ascent always includes
the leading, if any exists... It does seem like the point size passed
in does match the max height of a rendered character, but I couldn't
figure out how to find how much of the extra empty space is rendered
above, and how much is rendered below.

attached is the code I used to test, up and down can change the font
size, left and right change font, and you can type different text
stuff. It draws the size box, which for me always matches the rendered
surface. The two heights on the right are measured from the bottom of
the rendered surface. I'm curious what it does on pygame 1.7, if
anyone can check it out. I attached a png with how arial 64 comes out
for me.

import pygame
import sys

def ExpandRect(rect, size):
    rect.left -= size
    rect.top -= size
    rect.width += size*2
    rect.height += size*2

def PrintCenterRight(dest, font, text, pos):    
    surface = font.render(text, False, (255,255,255))
    drawpos = (pos[0] - surface.get_width(), pos[1] - surface.get_height()/2)
    dest.blit(surface, drawpos)

def PrintCenterLeft(dest, font, text, pos):    
    surface = font.render(text, False, (255,255,255))
    drawpos = (pos[0], pos[1] - surface.get_height()/2)
    dest.blit(surface, drawpos)
    
def DrawFont(dest, text, name, height):
    annotation_font = pygame.font.Font(pygame.font.get_default_font(), 14)
    PrintCenterLeft(dest, annotation_font, "%s: %d:" % (name, height), (20,20))

    origin = (80,60)
    font = pygame.font.Font(pygame.font.match_font(name, False, False), height)
    surface = font.render(text, False, (255,0,0,255), (32,32,32,255))
    dest.blit(surface, origin)
    render_rect = surface.get_rect()
    render_rect.topleft = (origin[0], origin[1])
    pygame.draw.rect(dest, (255,255,255), render_rect, 1)
    size = font.size(text)
    font_box = pygame.Rect(origin, size)
    pygame.draw.rect(dest, (255,255,0), font_box, 1)

    baseline = origin[1] + surface.get_height() + font.get_descent()
    pygame.draw.line(dest, (255,255,0), (render_rect.left - 10, baseline), (render_rect.right, baseline), 1)
    PrintCenterRight(dest, annotation_font, "baseline", (render_rect.left - 10, baseline))
    
    topline_offset = surface.get_height() + font.get_descent() - font.get_ascent()
    topline = origin[1] + topline_offset
    pygame.draw.line(dest, (255,255,0), (render_rect.left - 10, topline), (render_rect.left + 10, topline), 1)
    PrintCenterRight(dest, annotation_font, "ascent", (render_rect.left - 10, topline))

    nextline = origin[1] + font.get_linesize()
    pygame.draw.line(dest, (255,255,0), (render_rect.left - 10, nextline), (render_rect.right, nextline), 1)
    PrintCenterRight(dest, annotation_font, "next line", (render_rect.left - 10, nextline))

    height_line = origin[1] + surface.get_height() - font.get_height()
    pygame.draw.line(dest, (255,255,0), (render_rect.right - 10, height_line), (render_rect.right + 10, height_line), 1)
    PrintCenterLeft(dest, annotation_font, "returned height", (render_rect.right + 10, height_line))

    fontsizeline = origin[1] + surface.get_height() - height
    pygame.draw.line(dest, (255,255,0), (render_rect.right - 10, fontsizeline), (render_rect.right + 10, fontsizeline), 1)
    PrintCenterLeft(dest, annotation_font, "passed height", (render_rect.right + 10, fontsizeline))
    
    
def main():
    pygame.init()
    
    screen = pygame.display.set_mode((800, 400))
    font_list = pygame.font.get_fonts()
    font_index = font_list.index("arial")
    test_text = "Test Text, gj"
    height = 64
    
    print font_list
    
    while 1:
        for event in pygame.event.get():
            if event.type == pygame.QUIT: 
        		sys.exit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE: 
        			sys.exit()
                elif event.key == pygame.K_UP:
                    height = height + 1
                elif event.key == pygame.K_DOWN:
                    height = max(height - 1, 0)
                elif event.key == pygame.K_LEFT:
                    font_index = max(font_index - 1, 0)
                elif event.key == pygame.K_RIGHT:
                    font_index = min(font_index + 1, len(font_list) - 1)
                elif event.key == pygame.K_DELETE:
                    test_text = test_text[1:]
                elif event.key == pygame.K_BACKSPACE:
                    test_text = test_text[:-1]
                else:
                    test_text += event.unicode
		screen.fill((0,0,0))
        DrawFont(screen, test_text, font_list[font_index], height)
        pygame.display.flip()

if __name__ == '__main__':
       main()

Attachment: font_test_arial_1.6.PNG
Description: PNG image