GPU: Implement texture window

src/core/gpu.cpp

@@ -73,9 +73,11 @@ bool GPU::DoState(StateWrapper& sw)
   sw.Do(&m_render_state.texture_y_flip);
   sw.Do(&m_render_state.texpage_attribute);
   sw.Do(&m_render_state.texlut_attribute);
+  sw.Do(&m_render_state.texture_window_value);
   sw.Do(&m_render_state.texture_page_changed);
   sw.Do(&m_render_state.texture_color_mode_changed);
   sw.Do(&m_render_state.transparency_mode_changed);
+  sw.Do(&m_render_state.texture_window_changed);
 
   sw.Do(&m_drawing_area.left);
   sw.Do(&m_drawing_area.top);
@@ -113,6 +115,7 @@ bool GPU::DoState(StateWrapper& sw)
     m_render_state.texture_page_changed = true;
     m_render_state.texture_color_mode_changed = true;
     m_render_state.transparency_mode_changed = true;
+    m_render_state.texture_window_changed = true;
     UpdateGPUSTAT();
   }
 
@@ -437,10 +440,7 @@ void GPU::WriteGP0(u32 value)
 
       case 0xE2: // set texture window
       {
-        m_render_state.texture_window_mask_x = param & UINT32_C(0x1F);
-        m_render_state.texture_window_mask_y = (param >> 5) & UINT32_C(0x1F);
-        m_render_state.texture_window_offset_x = (param >> 10) & UINT32_C(0x1F);
-        m_render_state.texture_window_offset_y = (param >> 15) & UINT32_C(0x1F);
+        m_render_state.SetTextureWindow(value);
         Log_DebugPrintf("Set texture window %02X %02X %02X %02X", m_render_state.texture_window_mask_x,
                         m_render_state.texture_window_mask_y, m_render_state.texture_window_offset_x,
                         m_render_state.texture_window_offset_y);
@@ -895,6 +895,20 @@ void GPU::RenderState::SetFromPaletteAttribute(u16 value)
   texture_page_changed = true;
 }
 
+void GPU::RenderState::SetTextureWindow(u32 value)
+{
+  value &= TEXTURE_WINDOW_MASK;
+  if (texture_window_value == value)
+    return;
+
+  texture_window_mask_x = value & UINT32_C(0x1F);
+  texture_window_mask_y = (value >> 5) & UINT32_C(0x1F);
+  texture_window_offset_x = (value >> 10) & UINT32_C(0x1F);
+  texture_window_offset_y = (value >> 15) & UINT32_C(0x1F);
+  texture_window_value = value;
+  texture_window_changed = true;
+}
+
 bool GPU::DumpVRAMToFile(const char* filename, u32 width, u32 height, u32 stride, const void* buffer, bool remove_alpha)
 {
   std::vector<u32> rgba8_buf(width * height);

src/core/gpu.h

@@ -240,6 +240,7 @@ protected:
     static constexpr u16 PAGE_ATTRIBUTE_TEXTURE_PAGE_MASK = UINT16_C(0b0000000000011111);
     static constexpr u16 PAGE_ATTRIBUTE_MASK = UINT16_C(0b0000000111111111);
     static constexpr u16 PALETTE_ATTRIBUTE_MASK = UINT16_C(0b0111111111111111);
+    static constexpr u32 TEXTURE_WINDOW_MASK = UINT16_C(0b11111111111111111111);
 
     // decoded values
     u32 texture_page_x;
@@ -258,10 +259,12 @@ protected:
     // original values
     u16 texpage_attribute; // from register in rectangle modes/vertex in polygon modes
     u16 texlut_attribute;  // from vertex
+    u32 texture_window_value;
 
     bool texture_page_changed = false;
     bool texture_color_mode_changed = false;
     bool transparency_mode_changed = false;
+    bool texture_window_changed = false;
 
     bool IsChanged() const { return texture_page_changed || texture_color_mode_changed || transparency_mode_changed; }
 
@@ -274,11 +277,15 @@ protected:
     bool IsTransparencyModeChanged() const { return transparency_mode_changed; }
     void ClearTransparencyModeChangedFlag() { transparency_mode_changed = false; }
 
+    bool IsTextureWindowChanged() const { return texture_window_changed; }
+    void ClearTextureWindowChangedFlag() { texture_window_changed = false; }
+
     void SetFromPolygonTexcoord(u32 texcoord0, u32 texcoord1);
     void SetFromRectangleTexcoord(u32 texcoord);
 
     void SetFromPageAttribute(u16 value);
     void SetFromPaletteAttribute(u16 value);
+    void SetTextureWindow(u32 value);
   } m_render_state = {};
 
   struct DrawingArea

src/core/gpu_hw.cpp

@@ -46,9 +46,17 @@ void GPU_HW::LoadVertices(RenderCommand rc, u32 num_vertices)
         hw_vert.texpage = texpage;
 
         if (textured)
+        {
           hw_vert.texcoord = Truncate16(m_GP0_command[buffer_pos++]);
+          // auto [u, v] = HWVertex::DecodeTexcoord(hw_vert.texcoord);
+          // u = (u & (~(m_render_state.texture_window_mask_x * 8))) | ((m_render_state.texture_window_offset_x &
+          // m_render_state.texture_window_mask_x) * 8); v = (v & (~(m_render_state.texture_window_mask_y * 8))) |
+          // ((m_render_state.texture_window_offset_y & m_render_state.texture_window_mask_y) * 8);
+        }
         else
+        {
           hw_vert.texcoord = 0;
+        }
 
         hw_vert.padding = 0;
 
@@ -258,15 +266,24 @@ uniform vec2 u_transparent_alpha;
   in vec2 v_tex0;
   flat in ivec4 v_texpage;
   uniform sampler2D samp0;
+  uniform uvec4 u_texture_window;
 #endif
 
 out vec4 o_col0;
 
 #if TEXTURED
+ivec2 ApplyTextureWindow(ivec2 coords)
+{
+  uint x = (uint(coords.x) & ~(u_texture_window.x * 8u)) | ((u_texture_window.z & u_texture_window.x) * 8u);
+  uint y = (uint(coords.y) & ~(u_texture_window.y * 8u)) | ((u_texture_window.w & u_texture_window.y) * 8u);
+  return ivec2(int(x), int(y));
+}  
+
 vec4 SampleFromVRAM(vec2 coord)
 {
   // from 0..1 to 0..255
   ivec2 icoord = ivec2(coord * vec2(255.0));
+  icoord = ApplyTextureWindow(icoord);
 
   // adjust for tightly packed palette formats
   ivec2 index_coord = icoord;
@@ -493,7 +510,7 @@ void GPU_HW::DispatchRenderCommand(RenderCommand rc, u32 num_vertices)
   const bool restart_line_strip = (rc_primitive == HWRenderBatch::Primitive::LineStrip);
   const bool needs_flush =
     !IsFlushed() && (m_render_state.IsTextureColorModeChanged() || m_render_state.IsTransparencyModeChanged() ||
-                     buffer_overflow || rc_changed || restart_line_strip);
+                     m_render_state.IsTextureWindowChanged() || buffer_overflow || rc_changed || restart_line_strip);
   if (needs_flush)
     FlushRender();
 
@@ -544,5 +561,14 @@ void GPU_HW::DispatchRenderCommand(RenderCommand rc, u32 num_vertices)
     m_render_state.ClearTransparencyModeChangedFlag();
   }
 
+  if (m_render_state.IsTextureWindowChanged())
+  {
+    m_batch.texture_window_values[0] = m_render_state.texture_window_mask_x;
+    m_batch.texture_window_values[1] = m_render_state.texture_window_mask_y;
+    m_batch.texture_window_values[2] = m_render_state.texture_window_offset_x;
+    m_batch.texture_window_values[3] = m_render_state.texture_window_offset_y;
+    m_render_state.ClearTextureWindowChangedFlag();
+  }
+
   LoadVertices(rc, num_vertices);
 }

src/core/gpu_hw.h

@@ -51,6 +51,7 @@ protected:
     u32 texture_palette_x;
     u32 texture_palette_y;
     TransparencyMode transparency_mode;
+    std::array<u8, 4> texture_window_values;
 
     std::vector<HWVertex> vertices;
   };

src/core/gpu_hw_opengl.cpp

@@ -358,8 +358,9 @@ bool GPU_HW_OpenGL::CompileProgram(GL::Program& prog, bool transparent, bool tex
 
   if (textured)
   {
+    prog.RegisterUniform("u_texture_window");
     prog.RegisterUniform("samp0");
-    prog.Uniform1i(2, 0);
+    prog.Uniform1i(3, 0);
   }
 
   return true;
@@ -385,7 +386,11 @@ void GPU_HW_OpenGL::SetDrawState()
   }
 
   if (m_batch.texture_enable)
+  {
+    prog.Uniform4ui(2, m_batch.texture_window_values[0], m_batch.texture_window_values[1],
+                    m_batch.texture_window_values[2], m_batch.texture_window_values[3]);
     m_vram_read_texture->Bind();
+  }
 
   if (m_last_transparency_enable != m_batch.transparency_enable ||
       (m_last_transparency_enable && m_last_transparency_mode != m_batch.transparency_mode))