From 19d9322e676f2ad1e6a6088881a523f01dc0bac9 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <mclaughc@outlook.com>
Date: Sat, 14 Sep 2019 22:47:20 +1000
Subject: [PATCH] GPU: Fix texture coordinates when rendering paletted textures

---
 src/pse-sdl/sdl_interface.cpp |  2 +-
 src/pse/gpu.cpp               |  2 ++
 src/pse/gpu.h                 |  6 +++++-
 src/pse/gpu_hw.cpp            |  3 ++-
 src/pse/gpu_hw_opengl.cpp     | 34 +++++++++++++++++++++++++++-------
 5 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/src/pse-sdl/sdl_interface.cpp b/src/pse-sdl/sdl_interface.cpp
index 1dc63f3fe..337a87b92 100644
--- a/src/pse-sdl/sdl_interface.cpp
+++ b/src/pse-sdl/sdl_interface.cpp
@@ -289,7 +289,7 @@ void SDLInterface::RenderDisplay()
   if (!m_display_texture)
     return;
 
-  glViewport(0, 0, m_window_width, m_window_height);
+  glViewport(0, 0, m_window_width, m_window_height - 20);
   glDisable(GL_CULL_FACE);
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_SCISSOR_TEST);
diff --git a/src/pse/gpu.cpp b/src/pse/gpu.cpp
index 7091dc0f9..4a2b336c6 100644
--- a/src/pse/gpu.cpp
+++ b/src/pse/gpu.cpp
@@ -409,6 +409,8 @@ bool GPU::HandleRenderCommand()
                   ZeroExtend32(words_per_vertex));
 
   DispatchRenderCommand(rc, num_vertices);
+  FlushRender();
+  UpdateDisplay();
   return true;
 }
 
diff --git a/src/pse/gpu.h b/src/pse/gpu.h
index c2631b756..5dac6f547 100644
--- a/src/pse/gpu.h
+++ b/src/pse/gpu.h
@@ -83,7 +83,7 @@ protected:
     u32 bits;
 
     BitField<u32, u32, 0, 23> color_for_first_vertex;
-    BitField<u32, bool, 24, 1> texture_blending_raw; // not valid for lines
+    BitField<u32, bool, 24, 1> texture_blend_disable; // not valid for lines
     BitField<u32, bool, 25, 1> transparency_enable;
     BitField<u32, bool, 26, 1> texture_enable;
     BitField<u32, DrawRectangleSize, 27, 2> rectangle_size; // only for rectangles
@@ -91,6 +91,10 @@ protected:
     BitField<u32, bool, 27, 1> polyline;                    // only for lines
     BitField<u32, bool, 28, 1> shading_enable;              // 0 - flat, 1 = gouroud
     BitField<u32, Primitive, 29, 21> primitive;
+
+    // Helper functions.
+    bool IsTextureEnabled() const { return (primitive != Primitive::Line && texture_enable); }
+    bool IsTextureBlendingEnabled() const { return (IsTextureEnabled() && !texture_blend_disable); }
   };
 
   // TODO: Use BitField to do sign extending instead
diff --git a/src/pse/gpu_hw.cpp b/src/pse/gpu_hw.cpp
index a1599df6a..d64e7dda1 100644
--- a/src/pse/gpu_hw.cpp
+++ b/src/pse/gpu_hw.cpp
@@ -166,6 +166,7 @@ in vec2 a_tex0;
 
 out vec4 v_col0;
 #if TEXTURED
+  uniform vec2 u_tex_scale;
   out vec2 v_tex0;
 #endif
 
@@ -178,7 +179,7 @@ void main()
 
   v_col0 = a_col0;
   #if TEXTURED
-    v_tex0 = vec2(a_tex0.x / 4, a_tex0.y);
+    v_tex0 = vec2(a_tex0 * u_tex_scale);
   #endif
 }
 )";
diff --git a/src/pse/gpu_hw_opengl.cpp b/src/pse/gpu_hw_opengl.cpp
index ea4c1d206..0b05c27b3 100644
--- a/src/pse/gpu_hw_opengl.cpp
+++ b/src/pse/gpu_hw_opengl.cpp
@@ -148,12 +148,12 @@ bool GPU_HW_OpenGL::CompileProgram(GL::Program& prog, bool textured, bool blendi
   if (!prog.Link())
     return false;
 
-  prog.Bind();
-
   if (textured)
   {
+    prog.Bind();
+    prog.RegisterUniform("u_tex_scale");
     prog.RegisterUniform("samp0");
-    prog.Uniform1i(0, 0);
+    prog.Uniform1i(1, 0);
   }
 
   return true;
@@ -163,6 +163,29 @@ void GPU_HW_OpenGL::SetProgram(bool textured, bool blending)
 {
   const GL::Program& prog = textured ? (blending ? m_blended_texture_program : m_texture_program) : m_color_program;
   prog.Bind();
+
+  if (textured)
+  {
+    switch (m_texture_config.color_mode)
+    {
+      case GPU::TextureColorMode::Palette4Bit:
+        prog.Uniform2f(0, 1.0f / 4, 1.0f);
+        break;
+
+      case GPU::TextureColorMode::Palette8Bit:
+        prog.Uniform2f(0, 1.0f / 2, 1.0f);
+        break;
+
+      case GPU::TextureColorMode::Direct16Bit:
+        prog.Uniform2f(0, 1.0f, 1.0f);
+        break;
+
+      default:
+        break;
+    }
+
+    m_texture_page_texture->Bind();
+  }
 }
 
 void GPU_HW_OpenGL::SetViewport()
@@ -337,13 +360,10 @@ void GPU_HW_OpenGL::FlushRender()
   glDisable(GL_DEPTH_TEST);
   glEnable(GL_SCISSOR_TEST);
   glDepthMask(GL_FALSE);
-  SetProgram(m_batch_command.texture_enable, m_batch_command.texture_blending_raw);
+  SetProgram(m_batch_command.IsTextureEnabled(), m_batch_command.IsTextureBlendingEnabled());
   SetViewport();
   SetScissor();
 
-  if (m_batch_command.texture_enable)
-    m_texture_page_texture->Bind();
-
   glBindFramebuffer(GL_FRAMEBUFFER, m_framebuffer_fbo_id);
   glBindVertexArray(m_vao_id);