1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Licensed under the Apache License, Version 2.0 (the "License");
4 # you may not use this file except in compliance with the License.
5 # You may obtain a copy of the License at
7 # http://www.apache.org/licenses/LICENSE-2.0
9 # Unless required by applicable law or agreed to in writing, software
10 # distributed under the License is distributed on an "AS IS" BASIS,
11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 # See the License for the specific language governing permissions and
13 # limitations under the License.
15 # Portable example of using Gamnit with custom calls to OpenGL ES 2.0
18 # * The book OpenGL ES 2.0 Programming Guide
19 # * https://code.google.com/p/opengles-book-samples/source/browse/trunk/LinuxX11/Chapter_2/Hello_Triangle/Hello_Triangle.c
20 module portable_triangle
is
22 app_name
"gamnit Triangle"
23 app_namespace
"org.nitlanguage.triangle"
24 app_version
(1, 1, git_revision
)
31 # Our only program for the graphic card
32 var program
: GLProgram is noautoinit
34 # The only vertex sharder
35 var vertex_shader
: GLVertexShader is noautoinit
37 # The only fragment sharder
38 var fragment_shader
: GLFragmentShader is noautoinit
40 # Vertex data for the triangle
41 var vertex_array
: VertexArray is noautoinit
43 redef fun create_scene
48 assert display
!= null
50 print
"Width: {display.width}"
51 print
"Height: {display.height}"
53 assert glGetError
== gl_NO_ERROR
54 assert gl
.shader_compiler
else print
"Cannot compile shaders"
57 program
= new GLProgram
58 if not glIsProgram
(program
) then
59 print
"Program is not ok: {glGetError.to_s}\nLog:"
60 print glGetProgramInfoLog
(program
)
63 assert glGetError
== gl_NO_ERROR
66 vertex_shader
= new GLVertexShader
67 assert glIsShader
(vertex_shader
) else print
"Vertex shader is not ok: {glGetError}"
68 glShaderSource
(vertex_shader
, """
69 attribute vec4 vPosition;
72 gl_Position = vPosition;
74 """@glsl_vertex_shader
.to_cstring
)
75 glCompileShader
(vertex_shader
)
76 assert vertex_shader
.is_compiled
else print
"Vertex shader compilation failed with: {glGetShaderInfoLog(vertex_shader)} {glGetProgramInfoLog(program)}"
77 assert glGetError
== gl_NO_ERROR
80 fragment_shader
= new GLFragmentShader
81 assert glIsShader
(fragment_shader
) else print
"Fragment shader is not ok: {glGetError}"
82 glShaderSource
(fragment_shader
, """
83 precision mediump float;
86 gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
88 """@glsl_fragment_shader
.to_cstring
)
89 glCompileShader
(fragment_shader
)
90 assert fragment_shader
.is_compiled
else print
"Fragment shader compilation failed with: {glIsShader(fragment_shader)}"
91 assert glGetError
== gl_NO_ERROR
94 glAttachShader
(program
, vertex_shader
)
95 glAttachShader
(program
, fragment_shader
)
96 program
.bind_attrib_location
(0, "vPosition")
98 assert program
.is_linked
else print
"Linking failed: {glGetProgramInfoLog(program)}"
99 assert glGetError
== gl_NO_ERROR
102 var vertices
= [0.0, 0.5, 0.0, -0.5, -0.5, 0.0, 0.5, -0.5, 0.0]
103 vertex_array
= new VertexArray(0, 3, vertices
)
104 vertex_array
.attrib_pointer
109 redef fun frame_core
(display
)
111 glClearColor
(t
, t
, t
, 1.0)
113 assert glGetError
== gl_NO_ERROR
114 glViewport
(0, 0, display
.width
, display
.height
)
115 glClear gl_COLOR_BUFFER_BIT
119 glDrawArrays
(gl_TRIANGLES
, 0, 3)
124 if t
> 1.0 then t
= 0.0
130 glDeleteProgram program
131 glDeleteShader vertex_shader
132 glDeleteShader fragment_shader
135 var display
= display
136 if display
!= null then display
.close
140 if "NIT_TESTING".environ
== "true" then exit
(0)