diff --git a/src/font_renderer_alpha.h b/src/font_renderer_alpha.h index 5d8681f5..f596bbe2 100644 --- a/src/font_renderer_alpha.h +++ b/src/font_renderer_alpha.h @@ -46,13 +46,17 @@ public: m_trans(m_curves, m_mtx) { } - bool get_font_vmetrics(int& ascender, int& descender) { + int get_face_height() const { + return m_feng.face_height(); + } + + bool get_font_vmetrics(double& ascender, double& descender) { int face_height = m_feng.face_height(); if (face_height > 0) { double current_height = m_feng.height(); m_feng.height(1.0); - ascender = m_feng.ascender() * face_height; - descender = m_feng.descender() * face_height; + ascender = m_feng.ascender(); + descender = m_feng.descender(); m_feng.height(current_height); return true; } diff --git a/tests/agg_font_render_test.cpp b/tests/agg_font_render_test.cpp index b15558f2..a0b0c369 100644 --- a/tests/agg_font_render_test.cpp +++ b/tests/agg_font_render_test.cpp @@ -10,6 +10,12 @@ typedef struct { uint8_t b, g, r, a; } RenColor; typedef struct { int x, y, width, height; } RenRect; +// Mirrors stbtt_bakedchar. +struct GlyphBitmapInfo { + unsigned short x0, y0, x1, y1; + float xoff, yoff, xadvance; +}; + struct RenImage { RenColor *pixels; int width, height; @@ -17,14 +23,14 @@ struct RenImage { struct GlyphSetA { RenImage *image; - // FIXME: add glyphs information for AGG implementation - // stbtt_bakedchar glyphs[256]; + GlyphBitmapInfo glyphs[256]; }; struct RenFontA { font_renderer_alpha *renderer; float size; int height; + float ascender, descender; // For some reason the font's height used in renderer.c // when calling BakeFontBitmap is 0.5 off from 'height'. float height_bitmap; @@ -63,13 +69,20 @@ RenFontA* ren_load_font_agg(const char *filename, float size) { font->renderer = new font_renderer_alpha(false, false); font->renderer->load_font(filename); - int ascender, descender; + double ascender, descender; font->renderer->get_font_vmetrics(ascender, descender); - fprintf(stderr, "Font metrics ascender: %d descender: %d\n", ascender, descender); + int face_height = font->renderer->get_face_height(); + // Gives the font's ascender and descender like stbtt. + fprintf(stderr, "Font metrics ascender: %g descender: %g\n", ascender * face_height, descender * face_height); float scale = font->renderer->scale_for_em_to_pixels(size); - font->height = (ascender - descender) * scale + 0.5; - font->height_bitmap = (ascender - descender) * scale; + font->height = (ascender - descender) * face_height * scale + 0.5; + font->height_bitmap = (ascender - descender) * face_height * scale; + + font->descender = descender * font->height_bitmap; + font->ascender = ascender * font->height_bitmap; + + fprintf(stderr, "Font's pixel ascender: %g descender: %g sum: %g\n", font->ascender, font->descender, font->ascender - font->descender); fprintf(stderr, "Font height: %d\n", font->height); @@ -92,22 +105,32 @@ retry: agg::rendering_buffer ren_buf((agg::int8u *) set->image->pixels, width, height, -width * pixel_size); // FIXME: figure out how to precisely layout each glyph. - double x = 4, y = height - font->height * 3 / 2; + double x = 0, y = height; int res = 0; const agg::alpha8 text_color(0xff); for (int i = 0; i < 256; i++) { - if (x + font->height * 3 / 2 > width) { - x = 4; - y -= font->height * 3 / 2; + if (x + font->height > width) { + x = 0; + y -= font->height; } - if (y < 0) { + if (y - font->height < 0) { res = -1; break; } // FIXME: we are ignoring idx and with a char we cannot pass codepoint > 255. char text[2] = {char(i % 256), 0}; - // FIXME: using font->size below is wrong. - font->renderer->render_text(ren_buf, font->height_bitmap, text_color, x, y, text); + // FIXME: using font->height_bitmap below seems logically correct but + // the font size is bigger than what printed by BakeFontBitmap. + double x_next = x, y_next = y - font->height; + font->renderer->render_text(ren_buf, font->height_bitmap, text_color, x_next, y_next, text); + set->glyphs[i].x0 = x - 1; + set->glyphs[i].y0 = y - font->descender; + set->glyphs[i].x1 = x_next - 1; + set->glyphs[i].y1 = y + font->ascender; + set->glyphs[i].xoff = -1; + set->glyphs[i].yoff = -font->ascender; + set->glyphs[i].xadvance = x_next - x; + x = x_next; } /* retry with a larger image buffer if the buffer wasn't large enough */