fixes #531

tests/manyloc/named_argument_bug/tri_engine/tri_engine.nim

@@ -0,0 +1,106 @@
+import
+  algorithm,
+  tri_engine/config,
+  tri_engine/gfx/gl/gl,
+  tri_engine/gfx/gl/primitive,
+  tri_engine/gfx/gl/shader,
+  tri_engine/gfx/color
+
+const primitiveVs = """
+#version 330 core
+
+layout(location = 0) in vec2 pos;
+layout(location = 1) in vec2 texCoord;
+
+out vec2 uv;
+
+void main()
+{
+    gl_Position = vec4(pos, 0, 1);
+    uv = texCoord;
+}
+
+"""
+const primitiveFs = """
+#version 330 core
+
+in vec2 uv;
+out vec4 color;
+uniform sampler2D tex;
+uniform vec4 inColor;
+
+void main()
+{
+    color = texture(tex, uv) * inColor;
+}
+
+"""
+
+var gW, gH: Natural = 0
+
+proc w*(): int =
+  gW
+
+proc h*(): int =
+  gH
+
+type
+  PRenderer = ref object
+    primitiveProgram: TProgram
+    primitives: seq[PPrimitive]
+
+proc setupGL() =
+  ?glEnable(GLblend)
+  ?glBlendFunc(GLsrcAlpha, GLoneMinusSrcAlpha)
+  ?glClearColor(0.0, 0.0, 0.0, 1.0)
+  ?glPolygonMode(GLfrontAndBack, GLfill)
+
+proc newRenderer*(w, h: Positive): PRenderer =
+  gW = w
+  gH = h
+
+  new(result)
+  newSeq(result.primitives, 0)
+  loadExtensions()
+  setupGL()
+  result.primitiveProgram = newProgram(@[
+    newShaderFromSrc(primitiveVs, TShaderType.vert),
+    newShaderFromSrc(primitiveFs, TShaderType.frag)])
+
+proc draw(o: PRenderer, p: PPrimitive) =
+  let loc = proc(x: string): Glint =
+    result = glGetUniformLocation(o.primitiveProgram.id, x)
+    if result == -1:
+      raise newException(E_GL, "Shader error: " & x & " does not correspond to a uniform variable")
+
+  setUniformV4(loc("inColor"), p.color)
+  ?glActiveTexture(GLtexture0)
+  ?glBindTexture(GLtexture2D, p.tex.id.GLuint)
+  ?glUniform1i(loc("tex"), 0)
+
+  p.bindBufs()
+  setVertAttribPointers()
+
+  ?glDrawElements(p.vertMode.GLenum, p.indices.len.GLsizei, cGLunsignedShort, nil)
+
+proc draw*(o: PRenderer) =
+  ?glClear(GLcolorBufferBit)
+  o.primitiveProgram.use()
+
+  enableVertAttribArrs()
+  var zSortedPrimitives = o.primitives
+  zSortedPrimitives.sort(proc(x, y: PPrimitive): int =
+    if x.z < y.z:
+      -1
+    elif x.z > y.z:
+      1
+    else:
+      0)
+
+  for x in zSortedPrimitives:
+    o.draw(x)
+
+  disableVertAttribArrs()
+
+proc addPrimitive*(o: PRenderer, p: PPrimitive) =
+  o.primitives.add(p)