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. Image must be 24 or 32 bpp.");
  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   float alpha = lua_tonumber(L, 7)/255.0;
 108
 109   if(tex == NULL){
 110         return luaL_error(L, "ERROR: Can't draw. Image is null.");
 111   }
 112
 113   float w_half = tex->w/2.0;
 114   float h_half = tex->h/2.0;
 115
 116   glColor4f(1.0,1.0,1.0, alpha);
 117
 118   glPushMatrix();
 119   glTranslatef(x + w_half, y + h_half, 0.0f);
 120   glScalef(scale_x, scale_y, 1.0f);
 121   glRotatef(rot, 0.0f, 0.0f, -1.0f);
 122
 123   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex->texture);
 124   //draw here
 125   glBegin(GL_QUADS);
 126     // Top-left vertex (corner)
 127     glTexCoord2i(0, 0);
 128     glVertex2f(-w_half, -h_half);
 129
 130     // Bottom-left vertex (corner)
 131     glTexCoord2i(0, tex->h);
 132     glVertex2f(-w_half, h_half);
 133
 134     // Bottom-right vertex (corner)
 135     glTexCoord2i(tex->w, tex->h);
 136     glVertex2f(w_half, h_half);
 137
 138     // Top-right vertex (corner)
 139     glTexCoord2i(tex->w, 0);
 140     glVertex2f(w_half, -h_half);
 141   glEnd();
 142
 143   glPopMatrix();
 144
 145   return 0;
 146 }
 147
 148
 149 //function for displaying a frame of an animation
 150 //frames are laid out horizontally
 151 //frames start at 0
 152 int l_displayframe(lua_State *L){
 153   GLSurface *tex = (GLSurface*)lua_touserdata(L,1);
 154   float x = (float)lua_tonumber(L,2);
 155   float y = (float)lua_tonumber(L,3);
 156   int numframes = lua_tointeger(L,4);
 157   int frame = lua_tointeger(L,5);
 158   double rot = lua_tonumber(L,6);
 159   double scale_x = lua_tonumber(L,7);
 160   double scale_y = lua_tonumber(L,8);
 161   float alpha = lua_tonumber(L, 9)/255.0;
 162
 163   if(tex == NULL){
 164         return luaL_error(L, "ERROR: Can't draw. Image is null.");
 165   }
 166
 167   int width = tex->w/numframes;
 168   int frame_offset = frame * width;
 169
 170   float w_half = width/2.0;
 171   float h_half = tex->h/2.0;
 172
 173   glColor4f(1.0,1.0,1.0, alpha);
 174
 175   glPushMatrix();
 176   glTranslatef(x + w_half, y + h_half, 0.0f);
 177   glScalef(scale_x, scale_y, 1.0f);
 178   glRotatef(rot, 0.0f, 0.0f, -1.0f);
 179
 180   glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex->texture);
 181   //draw here
 182   glBegin(GL_QUADS);
 183     // Top-left vertex (corner)
 184     glTexCoord2i(frame_offset, 0);
 185     glVertex2f(-w_half, -h_half);
 186
 187     // Bottom-left vertex (corner)
 188     glTexCoord2i(frame_offset, tex->h);
 189     glVertex2f(-w_half, h_half);
 190
 191     // Bottom-right vertex (corner)
 192     glTexCoord2i(frame_offset + width, tex->h);
 193     glVertex2f(w_half, h_half);
 194
 195     // Top-right vertex (corner)
 196     glTexCoord2i(frame_offset + width, 0);
 197     glVertex2f(w_half, -h_half);
 198   glEnd();
 199
 200   glPopMatrix();
 201
 202   return 0;
 203 }
 204
 205
 206 //cursor toggler
 207 int l_show_cursor(lua_State *L){
 208   bool show = lua_toboolean(L, 1);
 209
 210   SDL_ShowCursor((show ? SDL_ENABLE : SDL_DISABLE));
 211
 212   return 0;
 213 }
 214
 215
 216 //fills screen with a color
 217 int l_fill_screen(lua_State *L){
 218   glClearColor(lua_tointeger(L,1)/255.0, lua_tointeger(L,2)/255.0, lua_tointeger(L,3)/255.0, 0.0f);
 219   glClear(GL_COLOR_BUFFER_BIT);
 220   return 0;
 221 }
 222
 223
 224 //free surface interface
 225 int l_delete_image(lua_State *L){
 226   GLSurface *tmp = (GLSurface*)lua_touserdata(L,1);
 227
 228   if(tmp == NULL){
 229         return luaL_error(L, "ERROR: Can't free. Image is null.");
 230   }
 231
 232   glDeleteTextures(1, &(tmp->texture));
 233   delete tmp;
 234   lua_pushnil(L);
 235   return 1;
 236 }
 237