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/* Pango |
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* Rendering routines to OpenGL |
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* |
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* Copyright (C) 2006 Marc Lehmann <pcg@goof.com> |
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* Copyright (C) 2004 Red Hat Software |
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* Copyright (C) 2000 Tor Lillqvist |
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* |
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* This file is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Library General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This file is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Library General Public License for more details. |
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* |
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* You should have received a copy of the GNU Library General Public |
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* License along with this library; if not, write to the |
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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* Boston, MA 02111-1307, USA. |
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*/ |
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|
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#include <math.h> |
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|
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#include "pangoopengl.h" |
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|
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#define PANGO_OPENGL_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_OPENGL_RENDERER, PangoOpenGLRendererClass)) |
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#define PANGO_IS_OPENGL_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_OPENGL_RENDERER)) |
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#define PANGO_OPENGL_RENDERER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_OPENGL_RENDERER, PangoOpenGLRendererClass)) |
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|
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typedef struct { |
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PangoRendererClass parent_class; |
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} PangoOpenGLRendererClass; |
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|
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struct _PangoOpenGLRenderer |
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{ |
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PangoRenderer parent_instance; |
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float r, g, b, a; // modulate |
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GLuint curtex; // current texture |
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}; |
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|
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G_DEFINE_TYPE (PangoOpenGLRenderer, pango_opengl_renderer, PANGO_TYPE_RENDERER) |
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|
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typedef struct |
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{ |
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uint8_t *bitmap; |
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int width, stride, height, top, left; |
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} Glyph; |
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|
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static void * |
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temp_buffer (size_t size) |
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{ |
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static char *buffer; |
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static size_t alloc; |
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|
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if (size > alloc) |
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{ |
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size = (size + 4095) & ~4095; |
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free (buffer); |
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alloc = size; |
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buffer = malloc (size); |
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} |
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|
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return buffer; |
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} |
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|
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static void |
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render_box (Glyph *glyph, int width, int height, int top) |
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{ |
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int i; |
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int left = 0; |
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|
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if (height > 2) |
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{ |
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height -= 2; |
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top++; |
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} |
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|
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if (width > 2) |
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{ |
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width -= 2; |
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left++; |
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} |
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|
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glyph->stride = (width + 3) & ~3; |
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glyph->width = width; |
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glyph->height = height; |
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glyph->top = top; |
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glyph->left = left; |
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|
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glyph->bitmap = temp_buffer (width * height); |
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memset (glyph->bitmap, 0, glyph->stride * height); |
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|
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for (i = width; i--; ) |
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glyph->bitmap [i] = glyph->bitmap [i + (height - 1) * glyph->stride] = 0xff; |
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|
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for (i = height; i--; ) |
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glyph->bitmap [i * glyph->stride] = glyph->bitmap [i * glyph->stride + (width - 1)] = 0xff; |
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} |
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|
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static void |
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font_render_glyph (Glyph *glyph, PangoFont *font, int glyph_index) |
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{ |
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FT_Face face; |
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|
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if (glyph_index & PANGO_GLYPH_UNKNOWN_FLAG) |
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{ |
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PangoFontMetrics *metrics; |
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|
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if (!font) |
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goto generic_box; |
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|
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metrics = pango_font_get_metrics (font, NULL); |
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if (!metrics) |
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goto generic_box; |
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|
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render_box (glyph, PANGO_PIXELS (metrics->approximate_char_width), |
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PANGO_PIXELS (metrics->ascent + metrics->descent), |
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PANGO_PIXELS (metrics->ascent)); |
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|
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pango_font_metrics_unref (metrics); |
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|
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return; |
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} |
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|
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face = pango_opengl_font_get_face (font); |
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|
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if (face) |
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{ |
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PangoOpenGLFont *glfont = (PangoOpenGLFont *)font; |
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|
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FT_Load_Glyph (face, glyph_index, glfont->load_flags); |
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FT_Render_Glyph (face->glyph, ft_render_mode_normal); |
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|
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glyph->width = face->glyph->bitmap.width; |
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glyph->stride = face->glyph->bitmap.pitch; |
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glyph->height = face->glyph->bitmap.rows; |
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glyph->top = face->glyph->bitmap_top; |
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glyph->left = face->glyph->bitmap_left; |
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glyph->bitmap = face->glyph->bitmap.buffer; |
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} |
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else |
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generic_box: |
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render_box (glyph, PANGO_UNKNOWN_GLYPH_WIDTH, PANGO_UNKNOWN_GLYPH_HEIGHT, PANGO_UNKNOWN_GLYPH_HEIGHT); |
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} |
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|
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typedef struct glyph_info { |
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tc_area tex; |
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int left, top; |
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} glyph_info; |
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|
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static void |
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free_glyph_info (glyph_info *g) |
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{ |
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tc_put (&g->tex); |
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g_slice_free (glyph_info, g); |
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} |
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|
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static void |
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draw_glyph (PangoRenderer *renderer_, PangoFont *font, PangoGlyph glyph, double x, double y) |
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{ |
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PangoOpenGLRenderer *renderer = PANGO_OPENGL_RENDERER (renderer_); |
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glyph_info *g; |
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float x1, y1, x2, y2; |
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|
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if (glyph & PANGO_GLYPH_UNKNOWN_FLAG) |
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{ |
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glyph = pango_opengl_get_unknown_glyph (font); |
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|
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if (glyph == PANGO_GLYPH_EMPTY) |
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glyph = PANGO_GLYPH_UNKNOWN_FLAG; |
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} |
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|
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g = _pango_opengl_font_get_cache_glyph_data (font, glyph); |
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|
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if (!g) |
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{ |
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Glyph bm; |
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font_render_glyph (&bm, font, glyph); |
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|
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g = g_slice_new (glyph_info); |
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|
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tc_get (&g->tex, bm.width, bm.height); |
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|
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g->left = bm.left; |
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g->top = bm.top; |
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|
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if (renderer->curtex) |
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{ |
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glEnd (); |
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renderer->curtex = 0; |
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} |
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|
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glBindTexture (GL_TEXTURE_2D, g->tex.name); |
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glPixelStorei (GL_UNPACK_ROW_LENGTH, bm.stride); |
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glPixelStorei (GL_UNPACK_ALIGNMENT, 1); |
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glTexSubImage2D (GL_TEXTURE_2D, 0, g->tex.x, g->tex.y, bm.width, bm.height, GL_ALPHA, GL_UNSIGNED_BYTE, bm.bitmap); |
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glPixelStorei (GL_UNPACK_ROW_LENGTH, 0); |
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glPixelStorei (GL_UNPACK_ALIGNMENT, 4); |
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|
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_pango_opengl_font_set_glyph_cache_destroy (font, (GDestroyNotify)free_glyph_info); |
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_pango_opengl_font_set_cache_glyph_data (font, glyph, g); |
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} |
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|
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x += g->left; |
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y -= g->top; |
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|
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x1 = g->tex.x * (1. / TC_WIDTH ); |
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y1 = g->tex.y * (1. / TC_HEIGHT); |
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x2 = g->tex.w * (1. / TC_WIDTH ) + x1; |
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y2 = g->tex.h * (1. / TC_HEIGHT) + y1; |
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|
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if (g->tex.name != renderer->curtex) |
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{ |
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if (renderer->curtex) |
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glEnd (); |
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|
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glBindTexture (GL_TEXTURE_2D, g->tex.name); |
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renderer->curtex = g->tex.name; |
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glBegin (GL_QUADS); |
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} |
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|
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glTexCoord2f (x1, y1); glVertex2i (x , y ); |
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glTexCoord2f (x2, y1); glVertex2i (x + g->tex.w, y ); |
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glTexCoord2f (x2, y2); glVertex2i (x + g->tex.w, y + g->tex.h); |
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glTexCoord2f (x1, y2); glVertex2i (x , y + g->tex.h); |
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} |
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|
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static void |
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draw_trapezoid (PangoRenderer *renderer_, |
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PangoRenderPart part, |
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double y1, |
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double x11, |
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double x21, |
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double y2, |
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double x12, |
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double x22) |
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{ |
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PangoOpenGLRenderer *renderer = (PangoOpenGLRenderer *)renderer_; |
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|
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if (renderer->curtex) |
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{ |
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glEnd (); |
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renderer->curtex = 0; |
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} |
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|
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glDisable (GL_TEXTURE_2D); |
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|
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glBegin (GL_QUADS); |
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glVertex2d (x11, y1); |
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glVertex2d (x12, y1); |
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glVertex2d (x22, y2); |
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glVertex2d (x21, y2); |
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glEnd (); |
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|
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glEnable (GL_TEXTURE_2D); |
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} |
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|
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void |
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pango_opengl_render_layout_subpixel (PangoLayout *layout, |
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int x, int y, |
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float r, float g, float b, float a) |
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{ |
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PangoContext *context; |
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PangoFontMap *fontmap; |
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PangoRenderer *renderer; |
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|
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context = pango_layout_get_context (layout); |
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fontmap = pango_context_get_font_map (context); |
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renderer = _pango_opengl_font_map_get_renderer (PANGO_OPENGL_FONT_MAP (fontmap)); |
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|
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PANGO_OPENGL_RENDERER (renderer)->r = r; |
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PANGO_OPENGL_RENDERER (renderer)->g = g; |
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PANGO_OPENGL_RENDERER (renderer)->b = b; |
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PANGO_OPENGL_RENDERER (renderer)->a = a; |
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|
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pango_renderer_draw_layout (renderer, layout, x, y); |
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} |
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|
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void |
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pango_opengl_render_layout (PangoLayout *layout, |
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int x, int y, |
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float r, float g, float b, float a) |
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{ |
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pango_opengl_render_layout_subpixel (layout, x * PANGO_SCALE, y * PANGO_SCALE, r, g, b, a); |
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} |
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|
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static void |
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pango_opengl_renderer_init (PangoOpenGLRenderer *renderer) |
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{ |
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renderer->r = 1.; |
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renderer->g = 1.; |
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renderer->b = 1.; |
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renderer->a = 1.; |
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} |
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|
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static void |
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prepare_run (PangoRenderer *renderer, PangoLayoutRun *run) |
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{ |
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PangoOpenGLRenderer *glrenderer = (PangoOpenGLRenderer *)renderer; |
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PangoColor *fg = 0; |
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GSList *l; |
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|
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renderer->underline = PANGO_UNDERLINE_NONE; |
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renderer->strikethrough = FALSE; |
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|
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for (l = run->item->analysis.extra_attrs; l; l = l->next) |
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{ |
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PangoAttribute *attr = l->data; |
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|
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switch (attr->klass->type) |
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{ |
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case PANGO_ATTR_UNDERLINE: |
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renderer->underline = ((PangoAttrInt *)attr)->value; |
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break; |
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|
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case PANGO_ATTR_STRIKETHROUGH: |
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renderer->strikethrough = ((PangoAttrInt *)attr)->value; |
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break; |
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|
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case PANGO_ATTR_FOREGROUND: |
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fg = &((PangoAttrColor *)attr)->color; |
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break; |
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|
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default: |
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break; |
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} |
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} |
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|
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if (fg) |
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glColor4f (fg->red / 65535., fg->green / 65535., fg->blue / 65535., glrenderer->a); |
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else |
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glColor4f (glrenderer->r, glrenderer->g, glrenderer->b, glrenderer->a); |
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} |
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|
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static void |
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draw_begin (PangoRenderer *renderer_) |
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{ |
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PangoOpenGLRenderer *renderer = (PangoOpenGLRenderer *)renderer_; |
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|
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renderer->curtex = 0; |
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|
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glEnable (GL_TEXTURE_2D); |
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glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); |
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glEnable (GL_BLEND); |
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gl_BlendFuncSeparate (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, |
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GL_ONE , GL_ONE_MINUS_SRC_ALPHA); |
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glEnable (GL_ALPHA_TEST); |
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glAlphaFunc (GL_GREATER, 0.01f); |
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} |
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|
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static void |
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draw_end (PangoRenderer *renderer_) |
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{ |
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PangoOpenGLRenderer *renderer = (PangoOpenGLRenderer *)renderer_; |
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|
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if (renderer->curtex) |
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glEnd (); |
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|
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glDisable (GL_ALPHA_TEST); |
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glDisable (GL_BLEND); |
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glDisable (GL_TEXTURE_2D); |
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} |
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|
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static void |
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pango_opengl_renderer_class_init (PangoOpenGLRendererClass *klass) |
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{ |
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PangoRendererClass *renderer_class = PANGO_RENDERER_CLASS (klass); |
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|
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renderer_class->draw_glyph = draw_glyph; |
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renderer_class->draw_trapezoid = draw_trapezoid; |
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renderer_class->prepare_run = prepare_run; |
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renderer_class->begin = draw_begin; |
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renderer_class->end = draw_end; |
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} |
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|
