def render(self, mode: gl.GLuint, instances: int = 1):
if self.ibo is not None:
count = self.ibo.size // 4
gl.glDrawElementsInstanced(mode, count, gl.GL_UNSIGNED_INT, None,
instances)
else:
gl.glDrawArraysInstanced(mode, 0, self.num_vertices, instances)
def transform(
self,
buffer: Buffer,
mode: gl.GLenum,
output_mode: gl.GLenum,
first: int = 0,
vertices: int = 0,
instances: int = 1,
buffer_offset=0,
):
"""Run a transform feedback.
:param Buffer buffer: The buffer to write the output
:param gl.GLenum mode: The input primitive mode
:param gl.GLenum output:mode: The output primitive mode
:param int first: Offset start vertex
:param int vertices: Number of vertices to render
:param int instances: Number of instances to render
:param int buffer_offset: Byte offset for the buffer (target)
"""
if vertices < 0:
raise ValueError(
f"Cannot determine the number of vertices: {vertices}")
if buffer_offset >= buffer.size:
raise ValueError("buffer_offset at end or past the buffer size")
gl.glBindVertexArray(self.glo)
gl.glEnable(gl.GL_RASTERIZER_DISCARD)
if buffer_offset > 0:
gl.glBindBufferRange(
gl.GL_TRANSFORM_FEEDBACK_BUFFER,
0,
buffer.glo,
buffer_offset,
buffer.size - buffer_offset,
)
else:
gl.glBindBufferBase(gl.GL_TRANSFORM_FEEDBACK_BUFFER, 0, buffer.glo)
gl.glBeginTransformFeedback(output_mode)
if self._ibo is not None:
count = self._ibo.size // 4
# TODO: Support first argument by offsetting pointer (second last arg)
gl.glDrawElementsInstanced(mode, count, gl.GL_UNSIGNED_INT, None,
instances)
else:
# print(f"glDrawArraysInstanced({mode}, {first}, {vertices}, {instances})")
gl.glDrawArraysInstanced(mode, first, vertices, instances)
gl.glEndTransformFeedback()
gl.glDisable(gl.GL_RASTERIZER_DISCARD)
def draw(self):
previous_draw_mode = gl.GLint(0)
gl.glGetIntegerv(gl.GL_POLYGON_MODE, byref(previous_draw_mode))
gl.glPolygonMode(gl.GL_FRONT_AND_BACK, gl.GL_LINE)
self.shader.use()
gl.glBindVertexArray(self.array)
# gl.glDrawElements(gl.GL_TRIANGLES, self.width * self.height * 6, gl.GL_UNSIGNED_INT, None)
gl.glDrawElementsInstanced(gl.GL_TRIANGLES, Chunk.cells * 6, gl.GL_UNSIGNED_INT, None, self.instances)
gl.glBindVertexArray(0)
self.shader.clear()
gl.glPolygonMode(gl.GL_FRONT_AND_BACK, previous_draw_mode.value)
def render(
self, mode: gl.GLenum, first: int = 0, vertices: int = 0, instances: int = 1
):
"""Render the VertexArray to the currently active framebuffer.
:param GLuint mode: Primitive type to render. TRIANGLES, LINES etc.
:param int first: The first vertex to render from
:param int vertices: Number of vertices to render
:param int instances: OpenGL instance, used in using vertices over and over
"""
gl.glBindVertexArray(self.glo)
if self._ibo is not None:
gl.glDrawElementsInstanced(mode, vertices, gl.GL_UNSIGNED_INT, first * 4, instances)
else:
gl.glDrawArraysInstanced(mode, first, vertices, instances)
def render(
self, mode: gl.GLenum, first: int = 0, vertices: int = 0, instances: int = 1
):
"""Render the VertexArray to the currently active framebuffer.
:param GLuint mode: Primitive type to render. TRIANGLES, LINES etc.
:param int first: The first vertex to render from
:param int vertices: Number of vertices to render
:param int instances: OpenGL instance, used in using vertices over and over
"""
gl.glBindVertexArray(self.glo)
if self._ibo is not None:
count = self._ibo.size // 4
# TODO: Support first argument by offsetting pointer (second last arg)
gl.glDrawElementsInstanced(mode, count, gl.GL_UNSIGNED_INT, None, instances)
else:
# print(f"glDrawArraysInstanced({mode}, {first}, {vertices}, {instances})")
gl.glDrawArraysInstanced(mode, first, vertices, instances)
