source/backends/opengl/texture_backend.cpp

   1 #include <msp/gl/extensions/arb_direct_state_access.h>
   2 #include <msp/gl/extensions/arb_texture_swizzle.h>
   3 #include <msp/gl/extensions/ext_framebuffer_object.h>
   4 #include <msp/gl/extensions/khr_debug.h>
   5 #include "gl.h"
   6 #include "error.h"
   7 #include "texture.h"
   8 #include "texture_backend.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 OpenGLTexture *OpenGLTexture::scratch_binding = 0;
  16
  17 OpenGLTexture::OpenGLTexture(unsigned t):
  18         target(t)
  19 {
  20         static bool alignment_init = false;
  21         if(!alignment_init)
  22         {
  23                 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  24                 alignment_init = true;
  25         }
  26 }
  27
  28 OpenGLTexture::~OpenGLTexture()
  29 {
  30         if(this==scratch_binding)
  31                 unbind_scratch();
  32         if(id)
  33                 glDeleteTextures(1, &id);
  34 }
  35
  36 void OpenGLTexture::create()
  37 {
  38         if(id)
  39                 throw invalid_operation("OpenGLTexture::create");
  40         if(ARB_direct_state_access)
  41                 glCreateTextures(target, 1, &id);
  42         else
  43                 glGenTextures(1, &id);
  44
  45 #ifdef DEBUG
  46         if(!debug_name.empty() && KHR_debug)
  47                 glObjectLabel(GL_TEXTURE, id, debug_name.size(), debug_name.c_str());
  48 #endif
  49 }
  50
  51 void OpenGLTexture::require_swizzle()
  52 {
  53         static Require _req(ARB_texture_swizzle);
  54 }
  55
  56 void OpenGLTexture::apply_swizzle()
  57 {
  58         ComponentSwizzle swizzle = static_cast<const Texture *>(this)->swizzle;
  59         if(swizzle==NO_SWIZZLE)
  60                 return;
  61
  62         const int *swizzle_order = get_gl_swizzle(swizzle);
  63         if(get_backend_api()==OPENGL_ES)
  64         {
  65                 set_parameter_i(GL_TEXTURE_SWIZZLE_R, swizzle_order[0]);
  66                 set_parameter_i(GL_TEXTURE_SWIZZLE_G, swizzle_order[1]);
  67                 set_parameter_i(GL_TEXTURE_SWIZZLE_B, swizzle_order[2]);
  68                 set_parameter_i(GL_TEXTURE_SWIZZLE_A, swizzle_order[3]);
  69         }
  70         else
  71         {
  72                 if(ARB_direct_state_access)
  73                         glTextureParameteriv(id, GL_TEXTURE_SWIZZLE_RGBA, swizzle_order);
  74                 else
  75                         glTexParameteriv(target, GL_TEXTURE_SWIZZLE_RGBA, swizzle_order);
  76         }
  77 }
  78
  79 void OpenGLTexture::set_parameter_i(unsigned param, int value) const
  80 {
  81         if(ARB_direct_state_access)
  82                 glTextureParameteri(id, param, value);
  83         else
  84                 glTexParameteri(target, param, value);
  85 }
  86
  87 void OpenGLTexture::generate_mipmap()
  88 {
  89         // glGenerateMipmap is defined here
  90         static Require _req(EXT_framebuffer_object);
  91
  92         if(ARB_direct_state_access)
  93                 glGenerateTextureMipmap(id);
  94         else
  95         {
  96                 bind_scratch();
  97                 glGenerateMipmap(target);
  98         }
  99 }
 100
 101 void OpenGLTexture::set_debug_name(const string &name)
 102 {
 103 #ifdef DEBUG
 104         debug_name = name;
 105         if(id && KHR_debug)
 106                 glObjectLabel(GL_TEXTURE, id, name.size(), name.c_str());
 107 #else
 108         (void)name;
 109 #endif
 110 }
 111
 112 void OpenGLTexture::bind_scratch()
 113 {
 114         if(!scratch_binding)
 115                 glActiveTexture(GL_TEXTURE0);
 116         if(scratch_binding!=this)
 117         {
 118                 if(scratch_binding && scratch_binding->target!=target)
 119                         glBindTexture(scratch_binding->target, 0);
 120                 glBindTexture(target, id);
 121                 scratch_binding = this;
 122         }
 123 }
 124
 125 void OpenGLTexture::unbind_scratch()
 126 {
 127         if(scratch_binding)
 128         {
 129                 glBindTexture(scratch_binding->target, 0);
 130                 scratch_binding = 0;
 131         }
 132 }
 133
 134 } // namespace GL
 135 } // namespace Msp