wolfhece.opengl.wolf_array_shader2d

Shared-resource 2D shader rendering for WolfArray.

Instead of creating a separate WolfArrayPlotShader per grid cell (each with its own shader program, z-texture upload, palette upload), we compile the shader program ONCE, upload the z-texture and palette ONCE, concatenate all visible quad-centers into a SINGLE VBO, and issue a SINGLE glDrawArrays call.

Author: HECE - University of Liege, Pierre Archambeau Date: 2024

Copyright (c) 2024 University of Liege. All rights reserved.

Module Contents

wolfhece.opengl.wolf_array_shader2d.SHADER_DIR

wolfhece.opengl.wolf_array_shader2d._DTYPE_GL_MAP

class wolfhece.opengl.wolf_array_shader2d.WolfArrayShader2D(owner)

Manages shared OpenGL resources for 2D shader rendering of a WolfArray.

Holds a back-reference to the owning WolfArray to access grid data, palette, mapviewer, and LOD helpers.

_owner

_program = None

_locs = None

_ztexture_id = None

_palette_id = None

_vao = None

_vbo = None

_merged_count = 0

_visible_key = None

_quad_cache

_color_values_buf

_pal_values = None

_pal_size = 0

_ztext_ready = False

_pal_ready = False

_dtype_define = None

_tile_textures

_tile_size = None

_n_tiles = (1, 1)

_tiled = False

_tile_ranges

_tile_visible_key = None

_init_resources(dtype_define=None)

Compile the shared shader program and locate uniforms.

Parameters:

dtype_define – Optional preprocessor define to inject into the geometry shader (‘SIGNED_INTEGER_DATA’ or ‘UNSIGNED_INTEGER_DATA’). When None the shader uses sampler2DRect (float textures).

_ensure_ztexture()

Upload the z-texture to the GPU.

If the array fits within GL_MAX_RECTANGLE_TEXTURE_SIZE in both dimensions, a single rectangle texture is created (fast path). Otherwise the data is split into a grid of tile textures, each within the hardware limit.

_ensure_palette()

Upload the palette 1-D texture to the GPU.

cleanup()

Release all shared GL resources.

_ensure_vao_vbo()

Create the shared VAO/VBO pair (once).

_upload_vbo(data)

Upload float32 vertex data to the shared VBO.

_set_common_uniforms(wa, lod)

Set uniforms shared between tiled and non-tiled draw paths.

_build_tile_vbo_data(wa, lod, istart, iend, jstart, jend)

Group visible quad centers by texture tile and merge into one VBO.

Returns:

(merged_vbo, tile_ranges) where merged_vbo is a concatenated np.float32 array and tile_ranges maps (tx, ty) to (vbo_offset, vertex_count) for glDrawArrays.

draw(sx: float = None, sy: float = None, xmin: float = None, ymin: float = None, xmax: float = None, ymax: float = None)

Draw using a single shared shader program.

When the array fits in a single texture, issues a single glDrawArrays call. When tiled (array exceeds max texture size), iterates over visible tiles, binding each tile’s texture and setting per-tile offset uniforms.