git.rot13.org Git - simavr/blob - examples/parts/hd44780_glut.c

   1 /*
   2         hd44780_glut.c
   3
   4         Copyright Luki <humbell@ethz.ch>
   5         Copyright 2011 Michel Pollet <buserror@gmail.com>
   6
   7         This file is part of simavr.
   8
   9         simavr is free software: you can redistribute it and/or modify
  10         it under the terms of the GNU General Public License as published by
  11         the Free Software Foundation, either version 3 of the License, or
  12         (at your option) any later version.
  13
  14         simavr is distributed in the hope that it will be useful,
  15         but WITHOUT ANY WARRANTY; without even the implied warranty of
  16         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17         GNU General Public License for more details.
  18
  19         You should have received a copy of the GNU General Public License
  20         along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "hd44780_glut.h"
  24
  25 #if __APPLE__
  26 #include <GLUT/glut.h>
  27 #else
  28 #include <GL/glut.h>
  29 #endif
  30
  31 #include "font.h"       // generated with gimp
  32
  33 static GLuint font_texture;
  34 static int charwidth = 5;
  35 static int charheight = 7;
  36
  37 void
  38 hd44780_gl_init()
  39 {
  40         glGenTextures(1, &font_texture);
  41         glBindTexture(GL_TEXTURE_2D, font_texture);
  42         glTexImage2D(GL_TEXTURE_2D, 0, 4,
  43                         lcd_font.width,
  44                         lcd_font.height, 0, GL_RGBA,
  45                 GL_UNSIGNED_BYTE,
  46                 lcd_font.pixel_data);
  47         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  48         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  49
  50         glMatrixMode(GL_TEXTURE);
  51         glLoadIdentity();
  52         glScalef(1.0f / (GLfloat) lcd_font.width, 1.0f / (GLfloat) lcd_font.height, 1.0f);
  53
  54         glMatrixMode(GL_MODELVIEW);
  55 }
  56
  57 static inline void
  58 glColor32U(uint32_t color)
  59 {
  60         glColor4f(
  61                         (float)((color >> 24) & 0xff) / 255.0f,
  62                         (float)((color >> 16) & 0xff) / 255.0f,
  63                         (float)((color >> 8) & 0xff) / 255.0f,
  64                         (float)((color) & 0xff) / 255.0f );
  65 }
  66
  67 void
  68 glputchar(char c,
  69                 uint32_t character,
  70                 uint32_t text,
  71                 uint32_t shadow)
  72 {
  73         int index = c;
  74         int left = index * charwidth;
  75         int right = index * charwidth + charwidth;
  76         int top = 0;
  77         int bottom = 7;
  78
  79         glEnable(GL_BLEND);
  80         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  81
  82         glDisable(GL_TEXTURE_2D);
  83         glColor32U(character);
  84         glBegin(GL_QUADS);
  85         glVertex3i(5, 7, 0);
  86         glVertex3i(0, 7, 0);
  87         glVertex3i(0, 0, 0);
  88         glVertex3i(5, 0, 0);
  89         glEnd();
  90
  91         glEnable(GL_BLEND);
  92         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  93
  94         glEnable(GL_TEXTURE_2D);
  95         glBindTexture(GL_TEXTURE_2D, font_texture);
  96         if (shadow) {
  97                 glColor32U(shadow);
  98                 glPushMatrix();
  99                 glTranslatef(.2f, .2f, 0);
 100                 glBegin(GL_QUADS);
 101                 glTexCoord2i(right, top);               glVertex3i(5, 0, 0);
 102                 glTexCoord2i(left, top);                glVertex3i(0, 0, 0);
 103                 glTexCoord2i(left, bottom);             glVertex3i(0, 7, 0);
 104                 glTexCoord2i(right, bottom);    glVertex3i(5, 7, 0);
 105                 glEnd();
 106                 glPopMatrix();
 107         }
 108         glColor32U(text);
 109         glBegin(GL_QUADS);
 110         glTexCoord2i(right, top);               glVertex3i(5, 0, 0);
 111         glTexCoord2i(left, top);                glVertex3i(0, 0, 0);
 112         glTexCoord2i(left, bottom);             glVertex3i(0, 7, 0);
 113         glTexCoord2i(right, bottom);    glVertex3i(5, 7, 0);
 114         glEnd();
 115
 116 }
 117
 118 void
 119 hd44780_gl_draw(
 120                 hd44780_t *b,
 121                 uint32_t background,
 122                 uint32_t character,
 123                 uint32_t text,
 124                 uint32_t shadow)
 125 {
 126         int rows = b->w;
 127         int lines = b->h;
 128         int border = 3;
 129
 130         glDisable(GL_TEXTURE_2D);
 131         glDisable(GL_BLEND);
 132         glColor32U(background);
 133         glTranslatef(border, border, 0);
 134         glBegin(GL_QUADS);
 135         glVertex3f(rows * charwidth + (rows - 1) + border, -border, 0);
 136         glVertex3f(-border, -border, 0);
 137         glVertex3f(-border, lines * charheight + (lines - 1) + border, 0);
 138         glVertex3f(rows * charwidth + (rows - 1) + border, lines * charheight
 139                 + (lines - 1) + border, 0);
 140         glEnd();
 141
 142         glColor3f(1.0f, 1.0f, 1.0f);
 143         const uint8_t offset[] = { 0, 0x40, 0x20, 0x60 };
 144         for (int v = 0 ; v < b->h; v++) {
 145                 glPushMatrix();
 146                 for (int i = 0; i < b->w; i++) {
 147                         glputchar(b->vram[offset[v] + i], character, text, shadow);
 148                         glTranslatef(6, 0, 0);
 149                 }
 150                 glPopMatrix();
 151                 glTranslatef(0, 8, 0);
 152         }
 153         hd44780_set_flag(b, HD44780_FLAG_DIRTY, 0);
 154 }