Add Shader Palette Lookup

data/shaders/copyframebuffer.frag

@@ -1,11 +1,11 @@
-#version 330
+#version 150
 
 uniform sampler2D uTexture;
 
 in vec2 fPosition;
 in vec2 fTextureCoordinate;
 
-layout (location = 0) out vec4 oColour;
+out vec4 oColour;
 
 void main()
 {

data/shaders/copyframebuffer.vert

@@ -1,10 +1,10 @@
-#version 330
+#version 150
 
 uniform ivec2 uScreenSize;
 uniform ivec4 uBounds;
 uniform ivec4 uTextureCoordinates;
 
-in int vIndex;
+in uint vIndex;
 
 out vec2 fPosition;
 out vec2 fTextureCoordinate;
@@ -13,22 +13,22 @@ void main()
 {
     vec2 pos;
     switch (vIndex) {
-    case 0:
+    case 0u:
         pos = uBounds.xy;
         fTextureCoordinate = uTextureCoordinates.xy;
         break;
-    case 1:
+    case 1u:
         pos = uBounds.zy;
         fTextureCoordinate = uTextureCoordinates.zy;
         break;
-    case 2:
+    case 2u:
-        pos = uBounds.zw;
-        fTextureCoordinate = uTextureCoordinates.zw;
-        break;
-    case 3:
         pos = uBounds.xw;
         fTextureCoordinate = uTextureCoordinates.xw;
         break;
+    case 3u:
+        pos = uBounds.zw;
+        fTextureCoordinate = uTextureCoordinates.zw;
+        break;
     }
 
     fPosition = pos;

data/shaders/drawimage.frag

@@ -1,14 +1,15 @@
-#version 330
+#version 150
 
 uniform ivec4       uClip;
 uniform int         uFlags;
 uniform vec4        uColour;
-uniform sampler2D   uTexture;
+uniform usampler2D  uTexture;
+uniform vec4        uPalette[256];
 
 in vec2 fPosition;
 in vec2 fTextureCoordinate;
 
-layout (location = 0) out vec4 oColour;
+out vec4 oColour;
 
 void main()
 {
@@ -18,7 +19,7 @@ void main()
         discard;
     }
 
-    vec4 texel = texture(uTexture, fTextureCoordinate);
+    vec4 texel = uPalette[texture(uTexture, fTextureCoordinate).r];
     if ((uFlags & 1) != 0)
     {
         oColour = vec4(uColour.rgb, uColour.a * texel.a);

data/shaders/drawimage.vert

@@ -1,10 +1,10 @@
-#version 330
+#version 150
 
 uniform ivec2 uScreenSize;
 uniform ivec4 uBounds;
 uniform ivec4 uTextureCoordinates;
 
-in int vIndex;
+in uint vIndex;
 
 out vec2 fPosition;
 out vec2 fTextureCoordinate;
@@ -13,22 +13,22 @@ void main()
 {
     vec2 pos;
     switch (vIndex) {
-    case 0:
+    case 0u:
         pos = uBounds.xy;
         fTextureCoordinate = uTextureCoordinates.xy;
         break;
-    case 1:
+    case 1u:
         pos = uBounds.zy;
         fTextureCoordinate = uTextureCoordinates.zy;
         break;
-    case 2:
+    case 2u:
-        pos = uBounds.zw;
-        fTextureCoordinate = uTextureCoordinates.zw;
-        break;
-    case 3:
         pos = uBounds.xw;
         fTextureCoordinate = uTextureCoordinates.xw;
         break;
+    case 3u:
+        pos = uBounds.zw;
+        fTextureCoordinate = uTextureCoordinates.zw;
+        break;
     }
 
     fPosition = pos;

data/shaders/drawimagemasked.frag

@@ -1,13 +1,14 @@
-#version 330
+#version 150
 
 uniform ivec4       uClip;
-uniform sampler2D   uTextureMask;
+uniform usampler2D  uTextureMask;
-uniform sampler2D   uTextureColour;
+uniform usampler2D  uTextureColour;
+uniform vec4        uPalette[256];
 
 in vec2 fPosition;
 in vec2 fTextureCoordinate;
 
-layout (location = 0) out vec4 oColour;
+out vec4 oColour;
 
 void main()
 {
@@ -17,7 +18,7 @@ void main()
         discard;
     }
 
-    vec4 mask = texture(uTextureMask, fTextureCoordinate);
+    vec4 mask = uPalette[texture(uTextureMask, fTextureCoordinate).r];
-    vec4 colour = texture(uTextureColour, fTextureCoordinate);
+    vec4 colour = uPalette[texture(uTextureColour, fTextureCoordinate).r];
     oColour = colour * mask;
 }

data/shaders/drawimagemasked.vert

@@ -1,9 +1,9 @@
-#version 330
+#version 150
 
 uniform ivec2 uScreenSize;
 uniform ivec4 uBounds;
 
-in int vIndex;
+in uint vIndex;
 
 out vec2 fPosition;
 out vec2 fTextureCoordinate;
@@ -12,22 +12,22 @@ void main()
 {
     vec2 pos;
     switch (vIndex) {
-    case 0:
+    case 0u:
         pos = uBounds.xy;
         fTextureCoordinate = vec2(0, 0);
         break;
-    case 1:
+    case 1u:
         pos = uBounds.zy;
         fTextureCoordinate = vec2(1, 0);
         break;
-    case 2:
+    case 2u:
-        pos = uBounds.zw;
-        fTextureCoordinate = vec2(1, 1);
-        break;
-    case 3:
         pos = uBounds.xw;
         fTextureCoordinate = vec2(0, 1);
         break;
+    case 3u:
+        pos = uBounds.zw;
+        fTextureCoordinate = vec2(1, 1);
+        break;
     }
 
     fPosition = pos;

data/shaders/drawline.frag

@@ -1,4 +1,4 @@
-#version 330
+#version 150
 
 uniform ivec2   uScreenSize;
 uniform ivec4   uClip;
@@ -6,7 +6,7 @@ uniform vec4    uColour;
 
 in vec2 fPosition;
 
-layout (location = 0) out vec4 oColour;
+out vec4 oColour;
 
 void main()
 {

data/shaders/drawline.vert

@@ -1,16 +1,16 @@
-#version 330
+#version 150
 
 uniform ivec2 uScreenSize;
 uniform ivec4 uBounds;
 
-in int vIndex;
+in uint vIndex;
 
 out vec2 fPosition;
 
 void main()
 {
     vec2 pos;
-    if (vIndex == 0)
+    if (vIndex == 0u)
     {
         pos = uBounds.xy;
     }

data/shaders/fillrect.frag

@@ -1,4 +1,4 @@
-#version 330
+#version 150
 
 uniform ivec2       uScreenSize;
 uniform ivec4       uClip;
@@ -9,7 +9,7 @@ uniform ivec4       uBounds;
 
 in vec2 fPosition;
 
-layout (location = 0) out vec4 oColour;
+out vec4 oColour;
 
 float getluma(vec3 colour)
 {

data/shaders/fillrect.vert

@@ -1,9 +1,9 @@
-#version 330
+#version 150
 
 uniform ivec2 uScreenSize;
 uniform ivec4 uBounds;
 
-in int vIndex;
+in uint vIndex;
 
 out vec2 fPosition;
 
@@ -11,18 +11,18 @@ void main()
 {
     vec2 pos;
     switch (vIndex) {
-    case 0:
+    case 0u:
         pos = uBounds.xy;
         break;
-    case 1:
+    case 1u:
         pos = uBounds.zy;
         break;
-    case 2:
+    case 2u:
-        pos = uBounds.zw;
-        break;
-    case 3:
         pos = uBounds.xw;
         break;
+    case 3u:
+        pos = uBounds.zw;
+        break;
     }
 
     fPosition = pos;

src/drawing/engines/opengl/CopyFramebufferShader.cpp

@@ -25,7 +25,7 @@ CopyFramebufferShader::CopyFramebufferShader() : OpenGLShaderProgram("copyframeb
     glGenBuffers(1, &_vbo);
     glGenVertexArrays(1, &_vao);
 
-    vec2i vertices[] = { 0, 1, 2, 3 };
+    GLuint vertices[] = { 0, 1, 2, 2, 1, 3 };
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
@@ -77,7 +77,7 @@ void CopyFramebufferShader::SetTexture(GLuint texture)
 void CopyFramebufferShader::Draw()
 {
     glBindVertexArray(_vao);
-    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
 }
 
 #endif /* DISABLE_OPENGL */

src/drawing/engines/opengl/DrawImageMaskedShader.cpp

@@ -25,7 +25,7 @@ DrawImageMaskedShader::DrawImageMaskedShader() : OpenGLShaderProgram("drawimagem
     glGenBuffers(1, &_vbo);
     glGenVertexArrays(1, &_vao);
 
-    vec2i vertices[] = { 0, 1, 2, 3 };
+    GLuint vertices[] = { 0, 1, 2, 2, 1, 3 };
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
@@ -53,6 +53,7 @@ void DrawImageMaskedShader::GetLocations()
     uBounds         = GetUniformLocation("uBounds");
     uTextureMask    = GetUniformLocation("uTextureMask");
     uTextureColour  = GetUniformLocation("uTextureColour");
+    uPalette        = GetUniformLocation("uPalette");
 
     vIndex          = GetAttributeLocation("vIndex");
 }
@@ -82,12 +83,17 @@ void DrawImageMaskedShader::SetTextureColour(GLuint texture)
     OpenGLAPI::SetTexture2D(1, texture);
 }
 
+void DrawImageMaskedShader::SetPalette(const vec4f *glPalette)
+{
+    glUniform4fv(uPalette, 256, (const GLfloat *) glPalette);
+}
+
 void DrawImageMaskedShader::Draw(sint32 left, sint32 top, sint32 right, sint32 bottom)
 {
     SetBounds(left, top, right, bottom);
 
     glBindVertexArray(_vao);
-    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
 }
 
 #endif /* DISABLE_OPENGL */

src/drawing/engines/opengl/DrawImageMaskedShader.h

@@ -18,6 +18,7 @@
 
 #include "GLSLTypes.h"
 #include "OpenGLShaderProgram.h"
+#include <SDL_pixels.h>
 
 class DrawImageMaskedShader : public OpenGLShaderProgram
 {
@@ -27,6 +28,7 @@ private:
     GLuint uBounds;
     GLuint uTextureMask;
     GLuint uTextureColour;
+    GLuint uPalette;
 
     GLuint vIndex;
 
@@ -42,6 +44,7 @@ public:
     void SetBounds(sint32 left, sint32 top, sint32 right, sint32 bottom);
     void SetTextureMask(GLuint texture);
     void SetTextureColour(GLuint texture);
+    void SetPalette(const vec4f *glPalette);
     void Draw(sint32 left, sint32 top, sint32 right, sint32 bottom);
 
 private:

src/drawing/engines/opengl/DrawImageShader.cpp

@@ -25,7 +25,7 @@ DrawImageShader::DrawImageShader() : OpenGLShaderProgram("drawimage")
     glGenBuffers(1, &_vbo);
     glGenVertexArrays(1, &_vao);
 
-    vec2i vertices[] = { 0, 1, 2, 3 };
+    GLuint vertices[] = { 0, 1, 2, 2, 1, 3 };
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
@@ -56,6 +56,7 @@ void DrawImageShader::GetLocations()
     uTexture            = GetUniformLocation("uTexture");
     uColour             = GetUniformLocation("uColour");
     uFlags              = GetUniformLocation("uFlags");
+    uPalette            = GetUniformLocation("uPalette");
 
     vIndex              = GetAttributeLocation("vIndex");
 }
@@ -95,12 +96,17 @@ void DrawImageShader::SetFlags(uint32 flags)
     glUniform1i(uFlags, flags);
 }
 
+void DrawImageShader::SetPalette(const vec4f *glPalette)
+{
+    glUniform4fv(uPalette, 256, (const GLfloat *) glPalette);
+}
+
 void DrawImageShader::Draw(sint32 left, sint32 top, sint32 right, sint32 bottom)
 {
     SetBounds(left, top, right, bottom);
 
     glBindVertexArray(_vao);
-    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
 }
 
 #endif /* DISABLE_OPENGL */

src/drawing/engines/opengl/DrawImageShader.h

@@ -18,6 +18,7 @@
 
 #include "GLSLTypes.h"
 #include "OpenGLShaderProgram.h"
+#include <SDL_pixels.h>
 
 class DrawImageShader : public OpenGLShaderProgram
 {
@@ -29,11 +30,14 @@ private:
     GLuint uTexture;
     GLuint uColour;
     GLuint uFlags;
+    GLuint uPalette;
 
     GLuint vIndex;
 
     GLuint _vbo;
     GLuint _vao;
+    
+    SDL_Color _palette[256];
 
 public:
     DrawImageShader();
@@ -46,7 +50,7 @@ public:
     void SetTexture(GLuint texture);
     void SetColour(vec4f colour);
     void SetFlags(uint32 flags);
-
+    void SetPalette(const vec4f *glPalette);
     void Draw(sint32 left, sint32 top, sint32 right, sint32 bottom);
 
 private:

src/drawing/engines/opengl/DrawLineShader.cpp

@@ -26,7 +26,7 @@ DrawLineShader::DrawLineShader() : OpenGLShaderProgram("drawline")
     glGenBuffers(1, &_vbo);
     glGenVertexArrays(1, &_vao);
 
-    vec2i vertices[] = { 0, 1 };
+    GLuint vertices[] = { 0, 1 };
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 

src/drawing/engines/opengl/FillRectShader.cpp

@@ -26,7 +26,7 @@ FillRectShader::FillRectShader() : OpenGLShaderProgram("fillrect")
     glGenBuffers(1, &_vbo);
     glGenVertexArrays(1, &_vao);
 
-    vec2i vertices[] = { 0, 1, 2, 3 };
+    GLuint vertices[] = { 0, 1, 2, 2, 1, 3 };
     glBindBuffer(GL_ARRAY_BUFFER, _vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
@@ -95,7 +95,7 @@ void FillRectShader::Draw(sint32 left, sint32 top, sint32 right, sint32 bottom)
     SetBounds(left, top, right, bottom);
 
     glBindVertexArray(_vao);
-    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
 }
 
 #endif /* DISABLE_OPENGL */

src/drawing/engines/opengl/OpenGLAPI.cpp

@@ -63,6 +63,7 @@ static const char * TryLoadAllProcAddresses()
     SetupOpenGLFunction(glEnd);
     SetupOpenGLFunction(glGenTextures);
     SetupOpenGLFunction(glGetError);
+	SetupOpenGLFunction(glPixelStorei);
     SetupOpenGLFunction(glReadPixels);
     SetupOpenGLFunction(glTexImage2D);
     SetupOpenGLFunction(glTexParameteri);
@@ -101,6 +102,7 @@ static const char * TryLoadAllProcAddresses()
     SetupOpenGLFunction(glUniform2i);
     SetupOpenGLFunction(glUniform4f);
     SetupOpenGLFunction(glUniform4i);
+    SetupOpenGLFunction(glUniform4fv);
     SetupOpenGLFunction(glUseProgram);
     SetupOpenGLFunction(glVertexAttribIPointer);
     SetupOpenGLFunction(glVertexAttribPointer);

src/drawing/engines/opengl/OpenGLAPI.h

@@ -35,6 +35,7 @@
 #define glEnd               __static__glEnd
 #define glGenTextures       __static__glGenTextures
 #define glGetError          __static__glGetError
+#define glPixelStorei       __static__glPixelStorei
 #define glReadPixels        __static__glReadPixels
 #define glTexImage2D        __static__glTexImage2D
 #define glTexParameteri     __static__glTexParameteri
@@ -61,6 +62,7 @@
 #undef glEnd
 #undef glGenTextures
 #undef glGetError
+#undef glPixelStorei
 #undef glReadPixels
 #undef glTexImage2D
 #undef glTexParameteri
@@ -80,6 +82,7 @@ typedef void   (APIENTRYP PFNGLENABLEPROC        )(GLenum cap);
 typedef void   (APIENTRYP PFNGLENDPROC           )(void);
 typedef GLenum (APIENTRYP PFNGLGETERRORPROC      )(void);
 typedef void   (APIENTRYP PFNGLGENTEXTURESPROC   )(GLsizei n, GLuint *textures);
+typedef void   (APIENTRYP PFNGLPIXELSTOREIPROC   )(GLenum pname, GLint param);
 typedef void   (APIENTRYP PFNGLREADPIXELSPROC    )(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid * pixels);
 typedef void   (APIENTRYP PFNGLTEXIMAGE2DPROC    )(GLenum target, GLint level, GLint internalFormat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
 typedef void   (APIENTRYP PFNGLTEXPARAMETERIPROC )(GLenum target, GLenum pname, GLint param);
@@ -110,6 +113,7 @@ GLAPI_DECL PFNGLENABLEPROC                      glEnable                    GLAP
 GLAPI_DECL PFNGLENDPROC                         glEnd                       GLAPI_SET;
 GLAPI_DECL PFNGLGENTEXTURESPROC                 glGenTextures               GLAPI_SET;
 GLAPI_DECL PFNGLGETERRORPROC                    glGetError                  GLAPI_SET;
+GLAPI_DECL PFNGLPIXELSTOREIPROC                 glPixelStorei               GLAPI_SET;
 GLAPI_DECL PFNGLREADPIXELSPROC                  glReadPixels                GLAPI_SET;
 GLAPI_DECL PFNGLTEXIMAGE2DPROC                  glTexImage2D                GLAPI_SET;
 GLAPI_DECL PFNGLTEXPARAMETERIPROC               glTexParameteri             GLAPI_SET;
@@ -148,6 +152,7 @@ GLAPI_DECL PFNGLUNIFORM1IPROC                   glUniform1i                 GLAP
 GLAPI_DECL PFNGLUNIFORM2IPROC                   glUniform2i                 GLAPI_SET;
 GLAPI_DECL PFNGLUNIFORM4FPROC                   glUniform4f                 GLAPI_SET;
 GLAPI_DECL PFNGLUNIFORM4IPROC                   glUniform4i                 GLAPI_SET;
+GLAPI_DECL PFNGLUNIFORM4FVPROC                  glUniform4fv                GLAPI_SET;
 GLAPI_DECL PFNGLUSEPROGRAMPROC                  glUseProgram                GLAPI_SET;
 GLAPI_DECL PFNGLVERTEXATTRIBIPOINTERPROC        glVertexAttribIPointer      GLAPI_SET;
 GLAPI_DECL PFNGLVERTEXATTRIBPOINTERPROC         glVertexAttribPointer       GLAPI_SET;

src/drawing/engines/opengl/OpenGLDrawingEngine.cpp

@@ -192,6 +192,7 @@ public:
 
     void Initialise();
     void Resize(sint32 width, sint32 height);
+    void ResetPalette();
 
     void Clear(uint32 colour) override;
     void FillRect(uint32 colour, sint32 x, sint32 y, sint32 w, sint32 h) override;
@@ -250,8 +251,9 @@ public:
 
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
-        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
+        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
         _context = SDL_GL_CreateContext(_window);
+        if(_context == nullptr) throw Exception("OpenGL 3.2 Not Available");
         SDL_GL_MakeCurrent(_window, _context);
 
         if (!OpenGLAPI::Initialise())
@@ -264,10 +266,6 @@ public:
         glEnable(GL_BLEND);
         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
-        // Do not draw the unseen side of the primitives
-        glEnable(GL_CULL_FACE);
-        glCullFace(GL_FRONT);
-
         _copyFramebufferShader = new CopyFramebufferShader();
     }
 
@@ -291,8 +289,7 @@ public:
                              colour.b / 255.0f,
                              colour.a / 255.0f };
         }
-        _drawingContext->GetTextureCache()
+        _drawingContext->ResetPalette();
-                       ->SetPalette(Palette);
     }
 
     void Invalidate(sint32 left, sint32 top, sint32 right, sint32 bottom) override
@@ -502,6 +499,15 @@ void OpenGLDrawingContext::Resize(sint32 width, sint32 height)
     _fillRectShader->SetScreenSize(width, height);
 }
 
+void OpenGLDrawingContext::ResetPalette()
+{
+    _textureCache->SetPalette(_engine->Palette);
+    _drawImageShader->Use();
+    _drawImageShader->SetPalette(_engine->GLPalette);
+    _drawImageMaskedShader->Use();
+    _drawImageMaskedShader->SetPalette(_engine->GLPalette);
+}
+
 void OpenGLDrawingContext::Clear(uint32 colour)
 {
     FillRect(colour, _clipLeft - _offsetX, _clipTop - _offsetY, _clipRight, _clipBottom);

src/drawing/engines/opengl/OpenGLShaderProgram.cpp

@@ -107,6 +107,7 @@ OpenGLShaderProgram::OpenGLShaderProgram(const char * name)
     _id = glCreateProgram();
     glAttachShader(_id, _vertexShader->GetShaderId());
     glAttachShader(_id, _fragmentShader->GetShaderId());
+    glBindFragDataLocation(_id, 0, "oColour");
 
     if (!Link())
     {

src/drawing/engines/opengl/TextureCache.cpp

@@ -1,4 +1,4 @@
-#pragma region Copyright (c) 2014-2016 OpenRCT2 Developers
+#pragma region Copyright (c) 2014-2016 OpenRCT2 Developers
 /*****************************************************************************
  * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
  *
@@ -53,14 +53,14 @@ void TextureCache::InvalidateImage(uint32 image)
 
 GLuint TextureCache::GetOrLoadImageTexture(uint32 image)
 {
-    auto kvp = _imageTextureMap.find(image);
+    auto kvp = _imageTextureMap.find(image & 0x7FFFF);
     if (kvp != _imageTextureMap.end())
     {
         return kvp->second;
     }
 
     GLuint texture = LoadImageTexture(image);
-    _imageTextureMap[image] = texture;
+    _imageTextureMap[image & 0x7FFFF] = texture;
 
     return texture;
 }
@@ -88,15 +88,15 @@ GLuint TextureCache::LoadImageTexture(uint32 image)
     GLuint texture;
     glGenTextures(1, &texture);
 
-    uint32 width, height;
+    rct_drawpixelinfo * dpi = GetImageAsDPI(image, 0);
-    void * pixels32 = GetImageAsARGB(image, 0, &width, &height);
 
     glBindTexture(GL_TEXTURE_2D, texture);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels32);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, dpi->width, dpi->height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, dpi->bits);
-    Memory::Free(pixels32);
+    
+    DeleteDPI(dpi);
 
     return texture;
 }
@@ -106,15 +106,15 @@ GLuint TextureCache::LoadGlyphTexture(uint32 image, uint8 * palette)
     GLuint texture;
     glGenTextures(1, &texture);
 
-    uint32 width, height;
+    rct_drawpixelinfo * dpi = GetGlyphAsDPI(image, palette);
-    void * pixels32 = GetGlyphAsARGB(image, palette, &width, &height);
 
     glBindTexture(GL_TEXTURE_2D, texture);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels32);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, dpi->width, dpi->height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, dpi->bits);
 
-    Memory::Free(pixels32);
+    DeleteDPI(dpi);
 
     return texture;
 }
@@ -135,6 +135,17 @@ void * TextureCache::GetImageAsARGB(uint32 image, uint32 tertiaryColour, uint32
     return pixels32;
 }
 
+rct_drawpixelinfo * TextureCache::GetImageAsDPI(uint32 image, uint32 tertiaryColour)
+{
+    rct_g1_element * g1Element = gfx_get_g1_element(image & 0x7FFFF);
+    sint32 width = g1Element->width;
+    sint32 height = g1Element->height;
+    
+    rct_drawpixelinfo * dpi = CreateDPI(width, height);
+    gfx_draw_sprite_software(dpi, image, -g1Element->x_offset, -g1Element->y_offset, tertiaryColour);
+    return dpi;
+}
+
 void * TextureCache::GetGlyphAsARGB(uint32 image, uint8 * palette, uint32 * outWidth, uint32 * outHeight)
 {
     rct_g1_element * g1Element = gfx_get_g1_element(image & 0x7FFFF);
@@ -151,6 +162,17 @@ void * TextureCache::GetGlyphAsARGB(uint32 image, uint8 * palette, uint32 * outW
     return pixels32;
 }
 
+rct_drawpixelinfo * TextureCache::GetGlyphAsDPI(uint32 image, uint8 * palette)
+{
+    rct_g1_element * g1Element = gfx_get_g1_element(image & 0x7FFFF);
+    sint32 width = g1Element->width;
+    sint32 height = g1Element->height;
+    
+    rct_drawpixelinfo * dpi = CreateDPI(width, height);
+    gfx_draw_sprite_palette_set_software(dpi, image, -g1Element->x_offset, -g1Element->y_offset, palette, nullptr);
+    return dpi;
+}
+
 void * TextureCache::ConvertDPIto32bpp(const rct_drawpixelinfo * dpi)
 {
     size_t numPixels = dpi->width * dpi->height;

src/drawing/engines/opengl/TextureCache.h

@@ -69,7 +69,9 @@ private:
     GLuint LoadImageTexture(uint32 image);
     GLuint LoadGlyphTexture(uint32 image, uint8 * palette);
     void * GetImageAsARGB(uint32 image, uint32 tertiaryColour, uint32 * outWidth, uint32 * outHeight);
+    rct_drawpixelinfo * GetImageAsDPI(uint32 image, uint32 tertiaryColour);
     void * GetGlyphAsARGB(uint32 image, uint8 * palette, uint32 * outWidth, uint32 * outHeight);
+    rct_drawpixelinfo * GetGlyphAsDPI(uint32 image, uint8 * palette);
     void * ConvertDPIto32bpp(const rct_drawpixelinfo * dpi);
     void FreeTextures();