Experimental code for Images drawn via 2d texture

So much faster than glDrawPixels()!!

dgl/Image.hpp

@@ -30,6 +30,7 @@ public:
     Image(const char* rawData, int width, int height, GLenum format = GL_BGRA, GLenum type = GL_UNSIGNED_BYTE) noexcept;
     Image(const char* rawData, const Size<int>& size, GLenum format = GL_BGRA, GLenum type = GL_UNSIGNED_BYTE) noexcept;
     Image(const Image& image) noexcept;
+    ~Image();
 
     void loadFromMemory(const char* rawData, int width, int height, GLenum format = GL_BGRA, GLenum type = GL_UNSIGNED_BYTE) noexcept;
     void loadFromMemory(const char* rawData, const Size<int>& size, GLenum format = GL_BGRA, GLenum type = GL_UNSIGNED_BYTE) noexcept;
@@ -57,6 +58,7 @@ private:
     Size<int> fSize;
     GLenum fFormat;
     GLenum fType;
+    mutable GLuint fTextureId;
 };
 
 // -----------------------------------------------------------------------

dgl/src/Image.cpp

@@ -16,6 +16,8 @@
 
 #include "../Image.hpp"
 
+#include <cstdio>
+
 START_NAMESPACE_DGL
 
 // -----------------------------------------------------------------------
@@ -24,7 +26,8 @@ Image::Image() noexcept
     : fRawData(nullptr),
       fSize(0, 0),
       fFormat(0),
-      fType(0)
+      fType(0),
+      fTextureId(0)
 {
 }
 
@@ -32,7 +35,8 @@ Image::Image(const char* rawData, int width, int height, GLenum format, GLenum t
     : fRawData(rawData),
       fSize(width, height),
       fFormat(format),
-      fType(type)
+      fType(type),
+      fTextureId(0)
 {
 }
 
@@ -40,7 +44,8 @@ Image::Image(const char* rawData, const Size<int>& size, GLenum format, GLenum t
     : fRawData(rawData),
       fSize(size),
       fFormat(format),
-      fType(type)
+      fType(type),
+      fTextureId(0)
 {
 }
 
@@ -48,10 +53,20 @@ Image::Image(const Image& image) noexcept
     : fRawData(image.fRawData),
       fSize(image.fSize),
       fFormat(image.fFormat),
-      fType(image.fType)
+      fType(image.fType),
+      fTextureId(0)
 {
 }
 
+Image::~Image()
+{
+    if (fTextureId != 0)
+    {
+        glDeleteTextures(1, &fTextureId);
+        fTextureId = 0;
+    }
+}
+
 void Image::loadFromMemory(const char* rawData, int width, int height, GLenum format, GLenum type) noexcept
 {
     loadFromMemory(rawData, Size<int>(width, height), format, type);
@@ -109,11 +124,59 @@ void Image::draw(int x, int y) const
 {
     if (! isValid())
         return;
+    if (fTextureId == 0)
+        glGenTextures(1, &fTextureId);
+    if (fTextureId == 0)
+    {
+        printf("texture Id still 0\n");
+        return;
+    }
+
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, fTextureId);
 
     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
     glPixelStorei(GL_PACK_ALIGNMENT, 1);
-    glRasterPos2i(x, fSize.getHeight()+y);
-    glDrawPixels(fSize.getWidth(), fSize.getHeight(), fFormat, fType, fRawData);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWidth(), getHeight(), 0, fFormat, fType, fRawData);
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+
+    float trans[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, trans);
+
+    glPushMatrix();
+
+    const GLint w2 = getWidth()/2;
+    const GLint h2 = getHeight()/2;
+
+    glTranslatef(x+w2, y+h2, 0.0f);
+
+    glBegin(GL_QUADS);
+      glTexCoord2f(0.0f, 1.0f);
+      glVertex2i(-w2, -h2);
+
+      glTexCoord2f(1.0f, 1.0f);
+      glVertex2i(getWidth()-w2, -h2);
+
+      glTexCoord2f(1.0f, 0.0f);
+      glVertex2i(getWidth()-w2, getHeight()-h2);
+
+      glTexCoord2f(0.0f, 0.0f);
+      glVertex2i(-w2, getHeight()-h2);
+    glEnd();
+
+    glPopMatrix();
+
+    glBindTexture(GL_TEXTURE_2D, 0);
+    glDisable(GL_TEXTURE_2D);
+
+//     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+//     glPixelStorei(GL_PACK_ALIGNMENT, 1);
+//     glRasterPos2i(x, fSize.getHeight()+y);
+//     glDrawPixels(fSize.getWidth(), fSize.getHeight(), fFormat, fType, fRawData);
 }
 
 void Image::draw(const Point<int>& pos) const
@@ -121,6 +184,8 @@ void Image::draw(const Point<int>& pos) const
     draw(pos.getX(), pos.getY());
 }
 
+// -----------------------------------------------------------------------
+
 Image& Image::operator=(const Image& image) noexcept
 {
     fRawData = image.fRawData;