examples: annotate examples

[nit.git] / lib / gamnit / examples / triangle / src / standalone_triangle.nit

diff --git a/lib/gamnit/examples/triangle/src/standalone_triangle.nit b/lib/gamnit/examples/triangle/src/standalone_triangle.nit
index 04e14db..a766fb2 100644 (file)
--- a/lib/gamnit/examples/triangle/src/standalone_triangle.nit
+++ b/lib/gamnit/examples/triangle/src/standalone_triangle.nit
@@ -19,7 +19,7 @@
 # References:
 # * The book OpenGL ES 2.0 Programming Guide
 # * https://code.google.com/p/opengles-book-samples/source/browse/trunk/LinuxX11/Chapter_2/Hello_Triangle/Hello_Triangle.c
-module standalone_triangle
+module standalone_triangle is example
 
 import app
 import gamnit::display
@@ -36,77 +36,77 @@ print "Width: {width}"
 print "Height: {height}"
 
 # Custom calls to OpenGL ES 2.0
-assert_no_gl_error
+assert glGetError == gl_NO_ERROR
 assert gl.shader_compiler else print "Cannot compile shaders"
 
 # GL program
-print gl.error.to_s
+print glGetError.to_s
 var program = new GLProgram
-if not program.is_ok then
-       print "Program is not ok: {gl.error.to_s}\nLog:"
-       print program.info_log
+if not glIsProgram(program) then
+       print "Program is not ok: {glGetError.to_s}\nLog:"
+       print glGetProgramInfoLog(program)
        abort
 end
-assert_no_gl_error
+assert glGetError == gl_NO_ERROR
 
 # Vertex shader
 var vertex_shader = new GLVertexShader
-assert vertex_shader.is_ok else print "Vertex shader is not ok: {gl.error}"
-vertex_shader.source = """
+assert glIsShader(vertex_shader) else print "Vertex shader is not ok: {glGetError}"
+glShaderSource(vertex_shader, """
 attribute vec4 vPosition;
 void main()
 {
   gl_Position = vPosition;
 }
-"""@glsl_vertex_shader.to_cstring
-vertex_shader.compile
-assert vertex_shader.is_compiled else print "Vertex shader compilation failed with: {vertex_shader.info_log} {program.info_log}"
-assert_no_gl_error
+"""@glsl_vertex_shader.to_cstring)
+glCompileShader vertex_shader
+assert vertex_shader.is_compiled else print "Vertex shader compilation failed with: {glGetShaderInfoLog(vertex_shader)} {glGetProgramInfoLog(program)}"
+assert glGetError == gl_NO_ERROR
 
 # Fragment shader
 var fragment_shader = new GLFragmentShader
-assert fragment_shader.is_ok else print "Fragment shader is not ok: {gl.error}"
-fragment_shader.source = """
+assert glIsShader(fragment_shader) else print "Fragment shader is not ok: {glGetError}"
+glShaderSource(fragment_shader, """
 precision mediump float;
 void main()
 {
        gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
 }
-"""@glsl_fragment_shader.to_cstring
-fragment_shader.compile
-assert fragment_shader.is_compiled else print "Fragment shader compilation failed with: {fragment_shader.info_log}"
-assert_no_gl_error
+"""@glsl_fragment_shader.to_cstring)
+glCompileShader fragment_shader
+assert fragment_shader.is_compiled else print "Fragment shader compilation failed with: {glGetShaderInfoLog(fragment_shader)}"
+assert glGetError == gl_NO_ERROR
 
 # Attach to program
-program.attach_shader vertex_shader
-program.attach_shader fragment_shader
+glAttachShader(program, vertex_shader)
+glAttachShader(program, fragment_shader)
 program.bind_attrib_location(0, "vPosition")
-program.link
-assert program.is_linked else print "Linking failed: {program.info_log}"
-assert_no_gl_error
+glLinkProgram program
+assert program.is_linked else print "Linking failed: {glGetProgramInfoLog(program)}"
+assert glGetError == gl_NO_ERROR
 
 # Draw!
 var vertices = [0.0, 0.5, 0.0, -0.5, -0.5, 0.0, 0.5, -0.5, 0.0]
 var vertex_array = new VertexArray(0, 3, vertices)
 vertex_array.attrib_pointer
-gl.clear_color(0.5, 0.0, 0.5, 1.0)
+glClearColor(0.5, 0.0, 0.5, 1.0)
 for i in [0..1000[ do
        printn "."
-       assert_no_gl_error
-       gl.viewport(0, 0, width, height)
-       gl.clear((new GLBuffer).color)
-       program.use
+       assert glGetError == gl_NO_ERROR
+       glViewport(0, 0, width, height)
+       glClear gl_COLOR_BUFFER_BIT
+       glUseProgram program
        vertex_array.enable
 
-       glDrawArrays(new GLDrawMode.triangles, 0, 3)
+       glDrawArrays(gl_TRIANGLES, 0, 3)
 
        display.flip
 end
 
 # Clean up
-program.delete
-vertex_shader.delete
-fragment_shader.delete
+glDeleteProgram program
+glDeleteShader vertex_shader
+glDeleteShader fragment_shader
 
 # Close gamnit
 display.close