funcs_video.cpp

   1 /*
   2 Copyright (c)2006-2008 - Brett Lajzer
   3
   4 See LICENSE for license information.
   5 */
   6
   7 #include <iostream>
   8
   9 #include <GL/gl.h>
  10 #include <GL/glu.h>
  11 #include <SDL/SDL.h>
  12 #include <SDL/SDL_image.h>
  13 #include <lua.hpp>
  14 #include "globals.h"
  15
  16
  17 //loads an SDL_Surface into a texture and returns the handle
  18 GLuint surfaceToTexture(lua_State *L, SDL_Surface *s){
  19         GLenum texture_format;
  20         GLuint tex;
  21
  22         if (s->format->BytesPerPixel == 4){
  23                 if (s->format->Rmask == 0x000000ff)
  24                         texture_format = GL_RGBA;
  25                 else
  26                         texture_format = GL_BGRA;
  27         } else if (s->format->BytesPerPixel == 3){
  28                 if (s->format->Rmask == 0x000000ff)
  29                         texture_format = GL_RGB;
  30                 else
  31                         texture_format = GL_BGR;
  32         }else{
  33                 return luaL_error(L, "ERROR: Can't create texture from image.");
  34         }
  35
  36         glGenTextures(1, &tex);
  37         glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex);
  38         glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  39     glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  40         glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, s->format->BytesPerPixel, s->w, s->h, 0, texture_format, GL_UNSIGNED_BYTE, s->pixels );
  41
  42         return tex;
  43 }
  44
  45
  46 //function for loading a surface from many different formats
  47 int l_getimage(lua_State *L){
  48   std::string filename(luaL_checkstring(L,1));
  49   std::map<std::string, GLSurface *>::iterator im = image_store.find(filename);
  50
  51   //search for the image in the store, if not found, load it
  52   if(im == image_store.end()){
  53     SDL_Surface *temp = IMG_Load(filename.c_str());
  54
  55     if(temp == NULL){
  56         return luaL_error(L, "ERROR: Can't find image file: \"%s\".", filename.c_str());
  57     }
  58
  59     GLuint texture = surfaceToTexture(L, temp);
  60
  61     GLSurface *surf = new GLSurface(texture, temp->w, temp->h);
  62     image_store[filename] = surf;
  63     lua_pushlightuserdata(L, surf);
  64     lua_pushinteger(L, (lua_Integer)temp->w);
  65     lua_pushinteger(L, (lua_Integer)temp->h);
  66
  67     SDL_FreeSurface(temp);
  68   }else{
  69     lua_pushlightuserdata(L, im->second);
  70     lua_pushinteger(L, (lua_Integer)im->second->w);
  71     lua_pushinteger(L, (lua_Integer)im->second->h);
  72   }
  73   return 3;
  74 }
  75
  76 //forces an image to be unloaded from memory
  77 int l_releaseimage(lua_State *L){
  78   std::string filename(luaL_checkstring(L,1));
  79   std::map<std::string, GLSurface *>::iterator im = image_store.find(filename);
  80
  81   if(im != image_store.end()){
  82         glDeleteTextures(1, &(im->second->texture));
  83         delete im->second;
  84     image_store.erase(im);
  85   }
  86
  87   return 0;
  88 }
  89
  90
  91 //function for updating the display surface
  92 int l_flip(lua_State *L){
  93   SDL_GL_SwapBuffers();
  94   return 0;
  95 }
  96
  97
  98 //function for simple displaying of images (non-animated)
  99 int l_display(lua_State *L){
 100   GLSurface *tex = (GLSurface *)lua_touserdata(L,1);
 101
 102   float x = (float)lua_tonumber(L,2);
 103   float y = (float)lua_tonumber(L,3);
 104   double rot = lua_tonumber(L,4);
 105   double scale_x = lua_tonumber(L,5);
 106   double scale_y = lua_tonumber(L,6);
 107
 108   if(tex == NULL){
 109         return luaL_error(L, "ERROR: Can't draw. Image is null.");
 110   }
 111
 112   float w_half = tex->w/2.0;
 113   float h_half = tex->h/2.0;
 114
 115   glPushMatrix();
 116   glTranslatef(x + w_half, y + h_half, 0.0f);
 117   glScalef(scale_x, scale_y, 1.0f);
 118   glRotatef(rot, 0.0f, 0.0f, -1.0f);
 119
 120   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex->texture);
 121   //draw here
 122   glBegin(GL_QUADS);
 123     // Top-left vertex (corner)
 124     glTexCoord2i(0, 0);
 125     glVertex2f(-w_half, -h_half);
 126
 127     // Bottom-left vertex (corner)
 128     glTexCoord2i(0, tex->h);
 129     glVertex2f(-w_half, h_half);
 130
 131     // Bottom-right vertex (corner)
 132     glTexCoord2i(tex->w, tex->h);
 133     glVertex2f(w_half, h_half);
 134
 135     // Top-right vertex (corner)
 136     glTexCoord2i(tex->w, 0);
 137     glVertex2f(w_half, -h_half);
 138   glEnd();
 139
 140   glPopMatrix();
 141
 142   return 0;
 143 }
 144
 145
 146 //function for displaying a frame of an animation
 147 //frames are laid out horizontally
 148 //frames start at 0
 149 int l_displayframe(lua_State *L){
 150   GLSurface *tex = (GLSurface*)lua_touserdata(L,1);
 151   float x = (float)lua_tonumber(L,2);
 152   float y = (float)lua_tonumber(L,3);
 153   int numframes = lua_tointeger(L,4);
 154   int frame = lua_tointeger(L,5);
 155   double rot = lua_tonumber(L,6);
 156   double scale_x = lua_tonumber(L,7);
 157   double scale_y = lua_tonumber(L,8);
 158
 159   if(tex == NULL){
 160         return luaL_error(L, "ERROR: Can't draw. Image is null.");
 161   }
 162
 163   int width = tex->w/numframes;
 164   int frame_offset = frame * width;
 165
 166   float w_half = width/2.0;
 167   float h_half = tex->h/2.0;
 168
 169   glPushMatrix();
 170   glTranslatef(x + w_half, y + h_half, 0.0f);
 171   glScalef(scale_x, scale_y, 1.0f);
 172   glRotatef(rot, 0.0f, 0.0f, -1.0f);
 173
 174   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex->texture);
 175   //draw here
 176   glBegin(GL_QUADS);
 177     // Top-left vertex (corner)
 178     glTexCoord2i(frame_offset, 0);
 179     glVertex2f(-w_half, -h_half);
 180
 181     // Bottom-left vertex (corner)
 182     glTexCoord2i(frame_offset, tex->h);
 183     glVertex2f(-w_half, h_half);
 184
 185     // Bottom-right vertex (corner)
 186     glTexCoord2i(frame_offset + width, tex->h);
 187     glVertex2f(w_half, h_half);
 188
 189     // Top-right vertex (corner)
 190     glTexCoord2i(frame_offset + width, 0);
 191     glVertex2f(w_half, -h_half);
 192   glEnd();
 193
 194   glPopMatrix();
 195
 196   return 0;
 197 }
 198
 199
 200 //cursor toggler
 201 int l_show_cursor(lua_State *L){
 202   bool show = lua_toboolean(L, 1);
 203
 204   SDL_ShowCursor((show ? SDL_ENABLE : SDL_DISABLE));
 205
 206   return 0;
 207 }
 208
 209
 210 //fills screen with a color
 211 int l_fill_screen(lua_State *L){
 212   glClearColor(lua_tointeger(L,1)/255.0, lua_tointeger(L,2)/255.0, lua_tointeger(L,3)/255.0, 0.0f);
 213   glClear(GL_COLOR_BUFFER_BIT);
 214   return 0;
 215 }
 216
 217
 218 //free surface interface
 219 int l_delete_image(lua_State *L){
 220   GLSurface *tmp = (GLSurface*)lua_touserdata(L,1);
 221
 222   if(tmp == NULL){
 223         return luaL_error(L, "ERROR: Can't free. Image is null.");
 224   }
 225
 226   glDeleteTextures(1, &(tmp->texture));
 227   delete tmp;
 228   lua_pushnil(L);
 229   return 1;
 230 }
 231