Added support for OpenGL 2.1

amulet_map_editor/api/opengl/canvas/canvas.py

@@ -13,9 +13,13 @@
     GL_ONE_MINUS_SRC_ALPHA,
     glDeleteTextures,
 )
+from OpenGL.error import GLError
+
 import uuid
 import sys
 
+from amulet_map_editor import log
+
 
 class BaseCanvas(glcanvas.GLCanvas):
     def __init__(self, parent: wx.Window):
@@ -30,22 +34,40 @@ def __init__(self, parent: wx.Window):
             style=wx.WANTS_CHARS,
         )
 
+        # create a UUID for the context. Used to get shaders
+        self._context_identifier = str(uuid.uuid4())
+
         if sys.platform == "linux":
             # setup the OpenGL context. This apparently fixes #84
             self._context = glcanvas.GLContext(self)
+            self.SetCurrent(self._context)
+            self._gl_texture_atlas = glGenTextures(1)  # Create the atlas texture location
         else:
-            context_attributes = wx.glcanvas.GLContextAttrs()
-            context_attributes.CoreProfile().OGLVersion(
-                3, 3
-            ).Robust().ResetIsolation().EndList()
-            self._context = glcanvas.GLContext(
-                self, ctxAttrs=context_attributes
-            )  # setup the OpenGL context
-        self.SetCurrent(self._context)
-        self._context_identifier = str(
-            uuid.uuid4()
-        )  # create a UUID for the context. Used to get shaders
-        self._gl_texture_atlas = glGenTextures(1)  # Create the atlas texture location
+            try:
+                context_attributes = wx.glcanvas.GLContextAttrs()
+                context_attributes.CoreProfile().OGLVersion(
+                    3, 3
+                ).Robust().ResetIsolation().EndList()
+                self._context = glcanvas.GLContext(
+                    self, ctxAttrs=context_attributes
+                )  # setup the OpenGL context
+                self.SetCurrent(self._context)
+                self._gl_texture_atlas = glGenTextures(1)  # Create the atlas texture location
+            except GLError:
+                log.info("Failed setting up modern OpenGL. Falling back to legacy OpenGL.")
+                try:
+                    context_attributes = wx.glcanvas.GLContextAttrs()
+                    context_attributes.CoreProfile().OGLVersion(
+                        2, 1
+                    ).Robust().ResetIsolation().EndList()
+                    self._context = glcanvas.GLContext(
+                        self, ctxAttrs=context_attributes
+                    )  # setup the OpenGL context
+                    self.SetCurrent(self._context)
+                    self._gl_texture_atlas = glGenTextures(1)  # Create the atlas texture location
+                except GLError as e:
+                    log.error("Failed setting up legacy OpenGL.")
+                    raise e
         self._setup_opengl()  # set some OpenGL states
 
     @property

amulet_map_editor/api/opengl/shaders/__init__.py

@@ -4,28 +4,44 @@
     glGenVertexArrays,
     GL_VERTEX_SHADER,
     GL_FRAGMENT_SHADER,
+    glGetString,
+    GL_SHADING_LANGUAGE_VERSION,
+    GL_VERSION,
 )
 import OpenGL.GL.shaders
 import os
 from typing import Dict, Tuple, Any
+import re
 
 shader_dir = os.path.join(os.path.dirname(__file__))
 _shaders: Dict[Tuple[str, str], Any] = {}
 
+GL_VERSION_MATCH = re.compile(r"^(?P<major>\d+)\.(?P<minor>\d+)?")
+
 
 def get_shader(
     context_identifier: str, shader_name: str
 ) -> OpenGL.GL.shaders.ShaderProgram:
     shader_key = (context_identifier, shader_name)
     if shader_key not in _shaders:
+        gl_version_match = GL_VERSION_MATCH.match(glGetString(GL_SHADING_LANGUAGE_VERSION).decode("utf-8"))
+        if gl_version_match:
+            gl_version_tuple = tuple(int(v) for v in gl_version_match.groups())
+            if gl_version_tuple >= (3, 30):
+                gl_version = "330"  # opengl 3.3
+            else:
+                gl_version = "120"  # opengl 2.1
+        else:
+            # in theory this shouldn't happen if the version is correctly formatted.
+            gl_version = "330"
 
         def compile_shader():
             return OpenGL.GL.shaders.compileProgram(
                 _load_shader(
-                    os.path.join(shader_dir, f"{shader_name}.vert"), GL_VERTEX_SHADER
+                    os.path.join(shader_dir, f"{shader_name}_{gl_version}.vert"), GL_VERTEX_SHADER
                 ),
                 _load_shader(
-                    os.path.join(shader_dir, f"{shader_name}.frag"), GL_FRAGMENT_SHADER
+                    os.path.join(shader_dir, f"{shader_name}_{gl_version}.frag"), GL_FRAGMENT_SHADER
                 ),
             )
 

amulet_map_editor/api/opengl/shaders/render_chunk.frag → amulet_map_editor/api/opengl/shaders/render_chunk_120.frag

@@ -1,14 +1,12 @@
-# version 330
+# version 120
 in vec2 fTexCoord;
 in vec4 fTexOffset;
 in vec3 fTint;
 
-out vec4 outColor;
-
 uniform sampler2D image;
 
 void main(){
-    vec4 texColor = texture(
+    vec4 texColor = texture2D(
     	image,
     	vec2(
 			mix(fTexOffset.x, fTexOffset.z, mod(fTexCoord.x, 1.0)),
@@ -18,5 +16,5 @@ void main(){
 	if(texColor.a < 0.02)
         discard;
     texColor.xyz = texColor.xyz * fTint * 0.85;
-	outColor = texColor;
+	gl_FragColor = texColor;
 }

amulet_map_editor/api/opengl/shaders/render_chunk.vert → amulet_map_editor/api/opengl/shaders/render_chunk_120.vert

@@ -1,12 +1,14 @@
-# version 330
+# version 120
+#extension GL_ARB_explicit_attrib_location : enable
+
 layout(location = 0) in vec3 positions;
 layout(location = 1) in vec2 vTexCoord;
 layout(location = 2) in vec4 vTexOffset;
 layout(location = 3) in vec3 vTint;
 
-out vec2 fTexCoord;
-out vec4 fTexOffset;
-out vec3 fTint;
+varying vec2 fTexCoord;
+varying vec4 fTexOffset;
+varying vec3 fTint;
 
 uniform mat4 transformation_matrix;
 

amulet_map_editor/api/opengl/shaders/render_chunk_330.frag

@@ -0,0 +1,20 @@
+# version 120
+in vec2 fTexCoord;
+in vec4 fTexOffset;
+in vec3 fTint;
+
+uniform sampler2D image;
+
+void main(){
+    vec4 texColor = texture2D(
+    	image,
+    	vec2(
+			mix(fTexOffset.x, fTexOffset.z, mod(fTexCoord.x, 1.0)),
+			mix(fTexOffset.y, fTexOffset.w, mod(fTexCoord.y, 1.0))
+		)
+	);
+	if(texColor.a < 0.02)
+        discard;
+    texColor.xyz = texColor.xyz * fTint * 0.85;
+	gl_FragColor = texColor;
+}

amulet_map_editor/api/opengl/shaders/render_chunk_330.vert

@@ -0,0 +1,20 @@
+# version 120
+#extension GL_ARB_explicit_attrib_location : enable
+
+layout(location = 0) in vec3 positions;
+layout(location = 1) in vec2 vTexCoord;
+layout(location = 2) in vec4 vTexOffset;
+layout(location = 3) in vec3 vTint;
+
+varying vec2 fTexCoord;
+varying vec4 fTexOffset;
+varying vec3 fTint;
+
+uniform mat4 transformation_matrix;
+
+void main(){
+    gl_Position = transformation_matrix * vec4(positions, 1.0);
+    fTexCoord = vTexCoord;
+    fTexOffset = vTexOffset;
+    fTint = vTint;
+}