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Ember blender with gamma correction into FontRenderer

This commit is contained in:
Francesco Abbate 2020-06-02 17:18:52 +02:00
parent bc74b2860d
commit ae032cd185
4 changed files with 54 additions and 35 deletions
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64
src/font_renderer.cpp
View File

@ -6,45 +6,62 @@
#include "font_renderer_alpha.h"
FontRenderer *FontRendererNew(unsigned int flags) {
typedef agg::blender_rgb_gamma<agg::rgba8, agg::order_bgra, agg::gamma_lut<> > blender_gamma_type;
class FontRendererImpl {
public:
FontRendererImpl(bool hinting, bool kerning, float gamma_value) :
m_renderer(hinting, kerning),
m_gamma_lut(double(gamma_value)),
m_blender()
{
m_blender.gamma(m_gamma_lut);
}
font_renderer_alpha& renderer_alpha() { return m_renderer; }
blender_gamma_type& blender() { return m_blender; }
private:
font_renderer_alpha m_renderer;
agg::gamma_lut<> m_gamma_lut;
blender_gamma_type m_blender;
};
FontRenderer *FontRendererNew(unsigned int flags, float gamma) {
bool hinting = ((flags & FONT_RENDERER_HINTING) != 0);
bool kerning = ((flags & FONT_RENDERER_KERNING) != 0);
font_renderer_alpha *font_renderer = new font_renderer_alpha(hinting, kerning);
return (FontRenderer *) font_renderer;
return new FontRendererImpl(hinting, kerning, gamma);
}
void FontRendererFree(FontRenderer *fr_) {
font_renderer_alpha *font_renderer = (font_renderer_alpha *) fr_;
void FontRendererFree(FontRenderer *font_renderer) {
delete font_renderer;
}
int FontRendererLoadFont(FontRenderer *fr_, const char *filename) {
font_renderer_alpha *font_renderer = (font_renderer_alpha *) fr_;
bool success = font_renderer->load_font(filename);
int FontRendererLoadFont(FontRenderer *font_renderer, const char *filename) {
bool success = font_renderer->renderer_alpha().load_font(filename);
return (success ? 0 : 1);
}
int FontRendererGetFontHeight(FontRenderer *fr_, float size) {
font_renderer_alpha *font_renderer = (font_renderer_alpha *) fr_;
int FontRendererGetFontHeight(FontRenderer *font_renderer, float size) {
font_renderer_alpha& renderer_alpha = font_renderer->renderer_alpha();
double ascender, descender;
font_renderer->get_font_vmetrics(ascender, descender);
int face_height = font_renderer->get_face_height();
float scale = font_renderer->scale_for_em_to_pixels(size);
renderer_alpha.get_font_vmetrics(ascender, descender);
int face_height = renderer_alpha.get_face_height();
float scale = renderer_alpha.scale_for_em_to_pixels(size);
return int((ascender - descender) * face_height * scale + 0.5);
}
int FontRendererBakeFontBitmap(FontRenderer *fr_, int font_height,
int FontRendererBakeFontBitmap(FontRenderer *font_renderer, int font_height,
void *pixels, int pixels_width, int pixels_height,
int first_char, int num_chars, GlyphBitmapInfo *glyphs)
{
font_renderer_alpha *font_renderer = (font_renderer_alpha *) fr_;
font_renderer_alpha& renderer_alpha = font_renderer->renderer_alpha();
const int pixel_size = 1;
memset(pixels, 0x00, pixels_width * pixels_height * pixel_size);
double ascender, descender;
font_renderer->get_font_vmetrics(ascender, descender);
renderer_alpha.get_font_vmetrics(ascender, descender);
const int ascender_px = int(ascender * font_height + 0.5);
const int descender_px = int(descender * font_height + 0.5);
@ -74,7 +91,7 @@ int FontRendererBakeFontBitmap(FontRenderer *fr_, int font_height,
const int y_baseline = y - pad_y - font_height;
double x_next = x, y_next = y_baseline;
font_renderer->render_codepoint(ren_buf, font_height_reduced, text_color, x_next, y_next, codepoint);
renderer_alpha.render_codepoint(ren_buf, font_height_reduced, text_color, x_next, y_next, codepoint);
int x_next_i = int(x_next + 1.0);
GlyphBitmapInfo& glyph_info = glyphs[i];
@ -134,16 +151,13 @@ void blend_solid_hspan(agg::rendering_buffer& rbuf, Blender& blender,
}
}
// destination implicitly BGRA32. Source implictly single-byte alpha coverage.
void FontRendererBlendGamma(uint8_t *dst, int dst_stride, uint8_t *src, int src_stride, int region_width, int region_height, FontRendererColor color) {
typedef agg::blender_rgb_gamma<agg::rgba8, agg::order_bgra, agg::gamma_lut<> > blender_type;
// destination implicitly BGRA32. Source implictly single-byte renderer_alpha coverage.
void FontRendererBlendGamma(FontRenderer *font_renderer, uint8_t *dst, int dst_stride, uint8_t *src, int src_stride, int region_width, int region_height, FontRendererColor color) {
blender_gamma_type& blender = font_renderer->blender();
agg::rendering_buffer dst_ren_buf(dst, region_width, region_height, dst_stride);
const agg::rgba8 color_a(color.r, color.g, color.b);
// FIXME: move blender object inside FontRenderer.
blender_type blender;
blender.gamma(1.8);
for (int x = 0, y = 0; y < region_height; y++) {
agg::int8u *covers = src + y * src_stride;
blend_solid_hspan<blender_type>(dst_ren_buf, blender, x, y, region_width, color_a, covers);
blend_solid_hspan<blender_gamma_type>(dst_ren_buf, blender, x, y, region_width, color_a, covers);
}
}

9
src/font_renderer.h
View File

@ -13,8 +13,8 @@ typedef struct {
float xoff, yoff, xadvance;
} GlyphBitmapInfo;
struct FontRenderer_;
typedef struct FontRenderer_ FontRenderer;
struct FontRendererImpl;
typedef struct FontRendererImpl FontRenderer;
enum {
FONT_RENDERER_HINTING = 1 << 0,
@ -25,7 +25,7 @@ typedef struct {
uint8_t r, g, b;
} FontRendererColor;
FontRenderer * FontRendererNew(unsigned int flags);
FontRenderer * FontRendererNew(unsigned int flags, float gamma);
void FontRendererFree(FontRenderer *);
@ -37,7 +37,8 @@ int FontRendererBakeFontBitmap(FontRenderer *, int font_height,
void *pixels, int pixels_width, int pixels_height,
int first_char, int num_chars, GlyphBitmapInfo *glyph_info);
void FontRendererBlendGamma(uint8_t *dst, int dst_stride,
void FontRendererBlendGamma(FontRenderer *,
uint8_t *dst, int dst_stride,
uint8_t *src, int src_stride,
int region_width, int region_height,
FontRendererColor color);

8
src/renderer.c
View File

@ -177,7 +177,8 @@ RenFont* ren_load_font(const char *filename, float size) {
font = check_alloc(calloc(1, sizeof(RenFont)));
font->size = size;
font->renderer = FontRendererNew(FONT_RENDERER_HINTING);
const float gamma = 1.8;
font->renderer = FontRendererNew(FONT_RENDERER_HINTING, gamma);
if (FontRendererLoadFont(font->renderer, filename)) {
free(font);
return NULL;
@ -319,7 +320,7 @@ void ren_draw_image(RenImage *image, RenRect *sub, int x, int y, RenColor color)
}
}
static void ren_draw_coverage_with_color(RenCoverageImage *image, RenRect *sub, int x, int y, RenColor color) {
static void ren_draw_coverage_with_color(FontRenderer *renderer, RenCoverageImage *image, RenRect *sub, int x, int y, RenColor color) {
if (color.a == 0) { return; }
clip_point_inside_rect(&x, &y, sub);
@ -336,6 +337,7 @@ static void ren_draw_coverage_with_color(RenCoverageImage *image, RenRect *sub,
d += x + y * surf->w;
const int surf_pixel_size = 4;
FontRendererBlendGamma(
renderer,
(uint8_t *) d, surf->w * surf_pixel_size,
s, image->width,
sub->width, sub->height,
@ -354,7 +356,7 @@ int ren_draw_text(RenFont *font, const char *text, int x, int y, RenColor color)
rect.y = g->y0;
rect.width = g->x1 - g->x0;
rect.height = g->y1 - g->y0;
ren_draw_coverage_with_color(set->coverage, &rect, x + g->xoff, y + g->yoff, color);
ren_draw_coverage_with_color(font->renderer, set->coverage, &rect, x + g->xoff, y + g->yoff, color);
x += g->xadvance;
}
return x;

8
tests/agg_font_render_test.c
View File

@ -60,9 +60,11 @@ RenFont* ren_load_font_agg(const char *filename, float size) {
font = check_alloc(calloc(1, sizeof(RenFont)));
font->size = size;
font->renderer = FontRendererNew(FONT_RENDERER_HINTING);
// FIXME check for errors
FontRendererLoadFont(font->renderer, filename);
font->renderer = FontRendererNew(FONT_RENDERER_HINTING, 1.8);
if (FontRendererLoadFont(font->renderer, filename)) {
free(font);
return NULL;
}
font->height = FontRendererGetFontHeight(font->renderer, size);
fprintf(stderr, "Font height: %d\n", font->height);