Code to work on OpenGL
This commit is contained in:
Kovid Goyal
200
kitty/develop_gl.py
Normal file
200
kitty/develop_gl.py
Normal file
@@ -0,0 +1,200 @@
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#!/usr/bin/env python3
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# vim:fileencoding=utf-8
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# License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
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import glfw
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import OpenGL.GL as gl
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import sys
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from PIL import Image
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import numpy
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import ctypes
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from kitty.shaders import ShaderProgram, VertexArrayObject
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vertex_shader = """
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# version 410
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in vec2 vertex;
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void main() {
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gl_Position = vec4(vertex, 0, 1);
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}
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"""
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fragment = """
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# version 410
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out vec4 final_color;
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void main(void)
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{
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final_color = vec4(1.0);
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}
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"""
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def key_callback(key, action):
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""" Sample keyboard callback function """
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print('Key: %s Action: %s pressed' % (key, action))
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def gl_get_unicode(k):
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ans = gl.glGetString(k)
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if isinstance(ans, bytes):
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try:
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ans = ans.decode('utf-8')
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except Exception:
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ans = repr(ans)
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return ans
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def on_resize(window, w, h):
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gl.glViewport(0, 0, w, h)
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def _main():
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# These Window hints are used to specify
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# which opengl version to use and other details
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# for the opengl context that will be created
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glfw.glfwWindowHint(glfw.GLFW_CONTEXT_VERSION_MAJOR, 4)
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glfw.glfwWindowHint(glfw.GLFW_CONTEXT_VERSION_MINOR, 1)
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glfw.glfwWindowHint(glfw.GLFW_OPENGL_PROFILE,
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glfw.GLFW_OPENGL_CORE_PROFILE)
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glfw.glfwWindowHint(glfw.GLFW_OPENGL_FORWARD_COMPAT, True)
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window = glfw.glfwCreateWindow(
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1024, 1024, "Trying this crap".encode('utf-8'), None, None)
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if not window:
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raise SystemExit("glfwCreateWindow failed")
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glfw.glfwMakeContextCurrent(window)
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glfw.glfwSwapInterval(1)
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glfw.glfwSetFramebufferSizeCallback(window, on_resize)
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# If everything went well the following calls
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# will display the version of opengl being used
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print('Vendor: %s' % (gl_get_unicode(gl.GL_VENDOR)))
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print('Opengl version: %s' % (gl_get_unicode(gl.GL_VERSION)))
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print('GLSL Version: %s' % (gl_get_unicode(gl.GL_SHADING_LANGUAGE_VERSION)))
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print('Renderer: %s' % (gl_get_unicode(gl.GL_RENDERER)))
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try:
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gl.glClearColor(0.5, 0.5, 0.5, 0)
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triangle_texture(window)
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finally:
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glfw.glfwDestroyWindow(window)
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def rectangle(window):
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program = ShaderProgram(vertex_shader, fragment)
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vao = VertexArrayObject()
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with program, vao:
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vao.make_rectangle()
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vertex = program.attribute_location('vertex')
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gl.glEnableVertexAttribArray(vertex)
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gl.glVertexAttribPointer(
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vertex, 2, gl.GL_FLOAT, gl.GL_FALSE, 0, None)
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while not glfw.glfwWindowShouldClose(window):
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gl.glClear(gl.GL_COLOR_BUFFER_BIT)
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with program, vao:
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# Activate the texture
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# glActiveTexture(GL_TEXTURE0)
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# glBindTexture(GL_TEXTURE_2D, texture_id)
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# sampler_loc = program.attribute_location('texture_sampler')
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# glUniform1i(sampler_loc, 0)
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# Modern GL makes the draw call really simple
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# All the complexity has been pushed elsewhere
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gl.glDrawElements(gl.GL_TRIANGLE_STRIP, 4, gl.GL_UNSIGNED_BYTE, None)
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# Now lets show our master piece on the screen
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glfw.glfwSwapBuffers(window)
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glfw.glfwWaitEvents()
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def triangle(window):
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program = ShaderProgram(vertex_shader, fragment)
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vao = VertexArrayObject()
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with program, vao:
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vao.make_triangle()
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vertex = program.attribute_location('vertex')
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gl.glEnableVertexAttribArray(vertex)
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gl.glVertexAttribPointer(
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vertex, 2, gl.GL_FLOAT, gl.GL_FALSE, 0, None)
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while not glfw.glfwWindowShouldClose(window):
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gl.glClear(gl.GL_COLOR_BUFFER_BIT)
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with program, vao:
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gl.glDrawArrays(gl.GL_TRIANGLES, 0, 3)
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glfw.glfwSwapBuffers(window)
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glfw.glfwWaitEvents()
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def triangle_texture(window):
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program = ShaderProgram(
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'''
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#version 410
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in vec2 vertex;
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in vec2 texture_position;
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out vec2 texture_position_out;
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void main() {
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gl_Position = vec4(vertex, 0, 1);
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texture_position_out = texture_position;
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}
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''',
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'''
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#version 410
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uniform sampler2D tex;
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in vec2 texture_position_out;
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out vec4 final_color;
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void main() {
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final_color = texture(tex, texture_position_out);
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// final_color = vec4(texture_position_out, 0, 1.0);
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}
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''')
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vao = VertexArrayObject()
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img = Image.open('/home/kovid/work/calibre/resources/images/library.png')
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img_data = numpy.array(list(img.getdata()), numpy.int8)
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with program, vao:
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program.set_2d_texture('tex', img_data, img.size[0], img.size[1])
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vao.make_triangle(add_texture=True)
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vertex = program.attribute_location('vertex')
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gl.glEnableVertexAttribArray(vertex)
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gl.glVertexAttribPointer(
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vertex, 2, gl.GL_FLOAT, gl.GL_FALSE, 0, None)
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texture_position = program.attribute_location('texture_position')
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gl.glEnableVertexAttribArray(texture_position)
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gl.glVertexAttribPointer(
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texture_position, 2, gl.GL_FLOAT, gl.GL_TRUE, 0, ctypes.c_void_p(6 * gl.sizeof(gl.GLfloat)))
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while not glfw.glfwWindowShouldClose(window):
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gl.glClear(gl.GL_COLOR_BUFFER_BIT)
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with program, vao:
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gl.glDrawArrays(gl.GL_TRIANGLES, 0, 3)
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glfw.glfwSwapBuffers(window)
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glfw.glfwWaitEvents()
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def on_error(code, msg):
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if isinstance(msg, bytes):
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try:
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msg = msg.decode('utf-8')
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except Exception:
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msg = repr(msg)
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print(msg, file=sys.stderr)
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def main():
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if not glfw.glfwInit():
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raise SystemExit('GLFW initialization failed')
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glfw.glfwSetErrorCallback(on_error)
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try:
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_main()
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finally:
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glfw.glfwTerminate()
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146
kitty/shaders.py
146
kitty/shaders.py
@@ -4,13 +4,8 @@
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from functools import lru_cache
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from OpenGL.GL import (
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glCreateProgram, GL_VERTEX_SHADER, GL_FRAGMENT_SHADER, glAttachShader,
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glLinkProgram, glGetProgramiv, glGetProgramInfoLog, GL_LINK_STATUS,
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GL_TRUE, glDeleteProgram, glDeleteShader, glCreateShader, glCompileShader,
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glGetShaderiv, GL_COMPILE_STATUS, glShaderSource, glGetShaderInfoLog,
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glGetUniformLocation, glGetAttribLocation
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)
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from OpenGL.arrays import ArrayDatatype
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import OpenGL.GL as gl
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class ShaderProgram:
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@@ -24,22 +19,23 @@ class ShaderProgram:
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:param fragment: The fragment shader
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"""
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self.program_id = glCreateProgram()
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vs_id = self.add_shader(vertex, GL_VERTEX_SHADER)
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frag_id = self.add_shader(fragment, GL_FRAGMENT_SHADER)
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self.program_id = gl.glCreateProgram()
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self.texture_id = None
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vs_id = self.add_shader(vertex, gl.GL_VERTEX_SHADER)
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frag_id = self.add_shader(fragment, gl.GL_FRAGMENT_SHADER)
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glAttachShader(self.program_id, vs_id)
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glAttachShader(self.program_id, frag_id)
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glLinkProgram(self.program_id)
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gl.glAttachShader(self.program_id, vs_id)
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gl.glAttachShader(self.program_id, frag_id)
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gl.glLinkProgram(self.program_id)
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if glGetProgramiv(self.program_id, GL_LINK_STATUS) != GL_TRUE:
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info = glGetProgramInfoLog(self.program_id)
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glDeleteProgram(self.program_id)
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glDeleteShader(vs_id)
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glDeleteShader(frag_id)
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if gl.glGetProgramiv(self.program_id, gl.GL_LINK_STATUS) != gl.GL_TRUE:
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info = gl.glGetProgramInfoLog(self.program_id)
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gl.glDeleteProgram(self.program_id)
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gl.glDeleteShader(vs_id)
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gl.glDeleteShader(frag_id)
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raise ValueError('Error linking shader program: %s' % info)
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glDeleteShader(vs_id)
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glDeleteShader(frag_id)
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gl.glDeleteShader(vs_id)
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gl.glDeleteShader(frag_id)
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def __hash__(self) -> int:
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return self.program_id
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@@ -52,24 +48,114 @@ class ShaderProgram:
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def add_shader(self, source: str, shader_type: int) -> int:
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' Compile a shader and return its id, or raise an exception if compilation fails '
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shader_id = glCreateShader(shader_type)
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shader_id = gl.glCreateShader(shader_type)
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try:
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glShaderSource(shader_id, source)
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glCompileShader(shader_id)
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if glGetShaderiv(shader_id, GL_COMPILE_STATUS) != GL_TRUE:
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info = glGetShaderInfoLog(shader_id)
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gl.glShaderSource(shader_id, source)
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gl.glCompileShader(shader_id)
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if gl.glGetShaderiv(shader_id, gl.GL_COMPILE_STATUS) != gl.GL_TRUE:
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info = gl.glGetShaderInfoLog(shader_id)
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raise ValueError('GLSL Shader compilation failed: %s' % info)
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return shader_id
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except Exception:
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glDeleteShader(shader_id)
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gl.glDeleteShader(shader_id)
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raise
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@lru_cache(maxlen=None)
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@lru_cache(maxsize=None)
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def uniform_location(self, name: str) -> int:
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' Return the id for the uniform variable `name` or -1 if not found. '
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return glGetUniformLocation(self.program_id, name)
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return gl.glGetUniformLocation(self.program_id, name)
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@lru_cache(maxlen=None)
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@lru_cache(maxsize=None)
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def attribute_location(self, name: str) -> int:
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' Return the id for the attribute variable `name` or -1 if not found. '
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return glGetAttribLocation(self.program_id, name)
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return gl.glGetAttribLocation(self.program_id, name)
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def __enter__(self):
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gl.glUseProgram(self.program_id)
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if self.texture_id is not None:
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gl.glActiveTexture(gl.GL_TEXTURE0)
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gl.glBindTexture(gl.GL_TEXTURE_2D, self.texture_id)
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gl.glUniform1i(self.texture_var, 0) # 0 because using GL_TEXTURE0
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def __exit__(self, *args):
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gl.glUseProgram(0)
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def set_2d_texture(self, var_name, data, width, height, data_type='rgba',
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min_filter=gl.GL_LINEAR, mag_filter=gl.GL_LINEAR,
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swrap=gl.GL_CLAMP_TO_EDGE, twrap=gl.GL_CLAMP_TO_EDGE):
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texture_id = self.texture_id = gl.glGenTextures(1)
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self.texture_var = self.uniform_location(var_name)
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gl.glPixelStorei(gl.GL_UNPACK_ALIGNMENT, 1 if data_type == 'red' else 4)
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gl.glBindTexture(gl.GL_TEXTURE_2D, texture_id)
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gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER, min_filter)
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gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER, mag_filter)
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gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_S, swrap)
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gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_T, twrap)
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internal_format, external_format = {
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'rgba': (gl.GL_RGBA8, gl.GL_RGBA),
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'rgb': (gl.GL_RGB8, gl.GL_RGB),
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'red': (gl.GL_RED, gl.GL_RED),
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}[data_type]
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gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, internal_format, width, height,
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0, external_format, gl.GL_UNSIGNED_BYTE, data)
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return texture_id
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def array(*args, dtype=gl.GLfloat):
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return (dtype * len(args))(*args)
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def make_buffer(data, target=gl.GL_ARRAY_BUFFER, usage=gl.GL_STREAM_DRAW):
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buf_id = gl.glGenBuffers(1)
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gl.glBindBuffer(target, buf_id)
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gl.glBufferData(target, ArrayDatatype.arrayByteCount(data), data, usage)
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return buf_id
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class VertexArrayObject:
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def __init__(self):
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self.vao_id = gl.glGenVertexArrays(1)
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self.is_active = False
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self.texture_id = None
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def __enter__(self):
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gl.glBindVertexArray(self.vao_id)
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self.is_active = True
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def __exit__(self, *a):
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gl.glBindVertexArray(0)
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self.is_active = False
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def make_triangle(self, width=0.8, height=0.8, add_texture=False, usage=gl.GL_STATIC_DRAW):
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if not self.is_active:
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raise RuntimeError('This VertexArrayObject is not active')
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if add_texture:
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vertices = array(
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0.0, height,
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-width, -height,
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width, -height,
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0.5, 1.0,
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0.0, 0.0,
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1.0, 0.0
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)
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else:
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vertices = array(
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0.0, height,
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-width, -height,
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width, -height,
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)
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make_buffer(vertices, usage=usage)
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def make_rectangle(self, left=-0.8, top=0.8, right=0.8, bottom=-0.8, usage=gl.GL_STATIC_DRAW):
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if not self.is_active:
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raise RuntimeError('This VertexArrayObject is not active')
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vertices = array(
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left, bottom,
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right, bottom,
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left, top,
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right, top
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)
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make_buffer(vertices, usage=usage)
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elements = array(0, 1, 2, 3, dtype=gl.GLubyte)
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make_buffer(elements, gl.GL_ELEMENT_ARRAY_BUFFER, usage=usage)
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Reference in New Issue
Block a user