path: root/chickadee/graphics/gl.scm

;;; Chickadee Game Toolkit
;;; Copyright © 2016, 2021 David Thompson <dthompson2@worcester.edu>
;;;
;;; Licensed under the Apache License, Version 2.0 (the "License");
;;; you may not use this file except in compliance with the License.
;;; You may obtain a copy of the License at
;;;
;;;    http://www.apache.org/licenses/LICENSE-2.0
;;;
;;; Unless required by applicable law or agreed to in writing, software
;;; distributed under the License is distributed on an "AS IS" BASIS,
;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;;; See the License for the specific language governing permissions and
;;; limitations under the License.

;;; Commentary:
;;
;; Custom wrappers over low level OpenGL commands that aren't part of
;; guile-opengl.
;;
;;; Code:

(define-module (chickadee graphics gl)
  #:use-module (srfi srfi-4)
  #:use-module ((system foreign) #:select (bytevector->pointer))
  #:use-module (gl)
  #:use-module (gl runtime)
  #:use-module ((gl low-level) #:renamer (symbol-prefix-proc '%))
  #:use-module (gl enums)
  #:use-module (gl runtime)
  #:use-module (gl types))

(re-export (%glClearColor . gl-clear-color)
           (%glScissor . gl-scissor)
           (%glBlendFunc . gl-blend-func)
           (%glBlendEquation . gl-blend-equation))

;;;
;;; 3.8.1 Texture Image Specification
;;;

(re-export (%glTexImage3D . gl-texture-image-3d)
           (%glTexImage2D . gl-texture-image-2d)
           (%glTexImage1D . gl-texture-image-1d))

;; For some reason, guile-opengl does not bind glGenerateMipmap, so we
;; have to do it ourselves.
(define-gl-procedure (glGenerateMipmap (target GLenum) -> void)
  "Generate mipmaps for the texture attached to target of the active
texture unit.")

(export (glGenerateMipmap . gl-generate-mipmap))

;;;
;;; 3.8.2 Alternate Texture Image Specification Commands
;;;

(re-export (%glCopyTexImage2D . gl-copy-texture-image-2d)
           (%glCopyTexImage1D . gl-copy-texture-image-1d)
           (%glCopyTexSubImage3D . gl-copy-texture-sub-image-3d)
           (%glCopyTexSubImage2D . gl-copy-texture-sub-image-2d)
           (%glCopyTexSubImage1D . gl-copy-texture-sub-image-1d)
           (%glTexSubImage3D . gl-texture-sub-image-3d)
           (%glTexSubImage2D . gl-texture-sub-image-2d)
           (%glTexSubImage1D . gl-texture-sub-image-1d))

;;;
;;; 3.8.3 Compressed Texture Images
;;;

(re-export (%glCompressedTexImage1D . gl-compressed-texture-image-1d)
           (%glCompressedTexImage2D . gl-compressed-texture-image-2d)
           (%glCompressedTexImage3D . gl-compressed-texture-image-3d)
           (%glCompressedTexSubImage1D . gl-compressed-texture-sub-image-1d)
           (%glCompressedTexSubImage2D . gl-compressed-texture-sub-image-2d)
           (%glCompressedTexSubImage3D . gl-compressed-texture-sub-image-3d))

;;;
;;; 3.8.4 Texture Parameters
;;;

(re-export  (%glTexParameteri . gl-texture-parameter)
            (%glBindTexture . gl-bind-texture))

;;;
;;; 6.1.4 Texture Queries
;;;

(re-export (%glGetTexImage . gl-get-tex-image))

;;;
;;; Instancing extension
;;;

(define-gl-procedure (glDrawArraysInstanced (mode GLenum)
                                            (first GLint)
                                            (count GLsizei)
                                            (primcount GLsizei)
                                            -> void)
  "Draw multiple instances of a set of arrays.")

(define-gl-procedure (glDrawElementsInstanced (mode GLenum)
                                              (count GLsizei)
                                              (type GLenum)
                                              (indices void-*)
                                              (primcount GLsizei)
                                              -> void)
  "Draw multiple instances of a set of elements.")

(define-gl-procedure (glVertexAttribDivisor (index GLuint)
                                            (divisor GLuint)
                                            -> void)
  "Modify the rate at which generic vertex attributes advance during
instanced rendering.")

(export (glDrawArraysInstanced . gl-draw-arrays-instanced)
        (glDrawElementsInstanced . gl-draw-elements-instanced)
        (glVertexAttribDivisor . gl-vertex-attrib-divisor))

;;;
;;; VBOs
;;;

(re-export (%glGenBuffers . gl-gen-buffers)
           (%glDeleteBuffers . gl-delete-buffers)
           (%glBufferData . gl-buffer-data)
           (%glBufferSubData . gl-buffer-sub-data)
           (%glMapBuffer . gl-map-buffer)
           (%glUnmapBuffer . gl-unmap-buffer))

;;;
;;; VAOs
;;;

(define-gl-procedure (glGenVertexArrays (n GLsizei)
                                        (arrays GLuint-*)
                                        -> void)
  "Generate N vertex arrays.")

(define-gl-procedure (glDeleteVertexArrays (n GLsizei)
                                           (arrays GLuint-*)
                                           -> void)
  "Delete vertex array objects.")

(define-gl-procedure (glBindVertexArray (array GLuint)
                                        -> void)
  "Bind vertex array object ARRAY.")

(define-gl-procedure (glEnableVertexAttribArray (index GLuint)
                                                -> void)
  "Enable or disable a generic vertex attribute array.")

(define-gl-procedure (glVertexAttribPointer (index GLuint)
                                            (size GLint)
                                            (type GLenum)
                                            (normalized GLboolean)
                                            (stride GLsizei)
                                            (pointer GLvoid-*)
                                            -> void)
  "Define an array of generic vertex attribute data.")

(define-gl-procedure (glDrawElements (mode GLenum)
                                     (count GLsizei)
                                     (type GLenum)
                                     (indices GLvoid-*)
                                     -> void)
  "Render primitives from array data.")

(export (glGenVertexArrays . gl-gen-vertex-arrays)
        (glDeleteVertexArrays . gl-delete-vertex-arrays)
        (glBindVertexArray . gl-bind-vertex-array)
        (glEnableVertexAttribArray . gl-enable-vertex-attrib-array)
        (glVertexAttribPointer . gl-vertex-attrib-pointer)
        (glDrawElements . gl-draw-elements))

(define-syntax-rule (with-gl-client-state state body ...)
  (begin
    (gl-enable-client-state state)
    body ...
    (gl-disable-client-state state)))

(export with-gl-client-state)

;;;
;;; Framebuffers
;;;

(define-gl-procedure (glGenFramebuffers (n GLsizei)
                                        (ids GLuint-*)
                                        -> void)
  "Generate framebuffer object names.")

(define-gl-procedure (glDeleteFramebuffers (n GLsizei)
                                           (framebuffers GLuint-*)
                                           -> void)
  "Delete framebuffer objects.")

(define-gl-procedure (glBindFramebuffer (target GLenum)
                                        (framebuffer GLuint)
                                        -> void)
  "Bind a framebuffer to a framebuffer target.")

(define-gl-procedure (glFramebufferTexture2D (target GLenum)
                                             (attachment GLenum)
                                             (textarget GLenum)
                                             (texture GLuint)
                                             (level GLint)
                                             -> void)
  "Attach a level of a texture object as a logical buffer to the
currently bound framebuffer object.")

(define-gl-procedure (glCheckFramebufferStatus (target GLenum)
                                               -> GLenum)
  "Return the framebuffer completeness status of a framebuffer
object.")

(define-gl-procedure (glGenRenderbuffers (n GLsizei)
                                         (ids GLuint-*)
                                         -> void)
  "Generate renderbuffer object names.")

(define-gl-procedure (glDeleteRenderbuffers (n GLsizei)
                                            (renderbuffers GLuint-*)
                                            -> void)
  "Delete renderbuffer objects.")

(define-gl-procedure (glBindRenderbuffer (target GLenum)
                                         (renderbuffer GLuint)
                                         -> void)
  "Bind a named renderbuffer object.")

(define-gl-procedure (glRenderbufferStorage (target GLenum)
                                            (internalformat GLenum)
                                            (width GLsizei)
                                            (height GLsizei)
                                            -> void)
  "Create and initialize a renderbuffer object's data store.")

(define-gl-procedure (glFramebufferRenderbuffer (target GLenum)
                                                (attachment GLenum)
                                                (renderbuffertarget GLenum)
                                                (renderbuffer GLuint)
                                                -> void)
  "Attach a renderbuffer object to a framebuffer object.")

(export (glGenFramebuffers . gl-gen-framebuffers)
        (glDeleteFramebuffers . gl-delete-framebuffers)
        (glBindFramebuffer . gl-bind-framebuffer)
        (glFramebufferTexture2D . gl-framebuffer-texture-2d)
        (glCheckFramebufferStatus . gl-check-framebuffer-status)
        (glGenRenderbuffers . gl-gen-renderbuffers)
        (glDeleteRenderbuffers . gl-delete-renderbuffers)
        (glBindRenderbuffer . gl-bind-renderbuffer)
        (glRenderbufferStorage . gl-renderbuffer-storage)
        (glFramebufferRenderbuffer . gl-framebuffer-renderbuffer))

(re-export (%glDrawBuffers . gl-draw-buffers))


;;;
;;; Shaders
;;;

(define-gl-procedure (glUniform1ui (location GLint)
                                   (v0 GLuint)
                                   -> void)
  "Specify the value of a uniform variable for the current program object")

(define-gl-procedure (glUniform1uiv (location GLint)
                                    (count GLint)
                                    (ptr GLvoid-*)
                                    -> void)
  "Specify the value of a uniform variable for the current program object")

(export (glUniform1ui . gl-uniform1ui)
        (glUniform1uiv . gl-uniform1uiv))

(re-export (%glUseProgram . gl-use-program)
           (%glDeleteProgram .  gl-delete-program)
           (%glDetachShader .  gl-detach-shader)
           (%glLinkProgram .  gl-link-program)
           (%glBindAttribLocation .  gl-bind-attrib-location)
           (%glAttachShader .  gl-attach-shader)
           (%glGetAttribLocation .  gl-get-attrib-location)
           (%glGetUniformLocation .  gl-get-uniform-location)
           (%glCreateProgram .  gl-create-program)
           (%glGetProgramInfoLog .  gl-get-program-info-log)
           (%glGetProgramiv .  gl-get-programiv)
           (%glDeleteProgram .  gl-delete-program)
           (%glDeleteShader .  gl-delete-shader)
           (%glGetShaderiv .  gl-get-shaderiv)
           (%glGetShaderInfoLog .  gl-get-shader-info-log)
           (%glCompileShader .  gl-compile-shader)
           (%glShaderSource .  gl-shader-source)
           (%glCreateShader .  gl-create-shader)
           (%glGetActiveUniform . gl-get-active-uniform)
           (%glGetActiveAttrib . gl-get-active-attrib)
           (%glUniform1i .  gl-uniform1i)
           (%glUniform1iv . gl-uniform1iv)
           (%glUniform2i .  gl-uniform2i)
           (%glUniform3i .  gl-uniform3i)
           (%glUniform4i .  gl-uniform4i)
           (%glUniform1f . gl-uniform1f)
           (%glUniform1fv .  gl-uniform1fv)
           (%glUniform2f .  gl-uniform2f)
           (%glUniform2fv .  gl-uniform2fv)
           (%glUniform3f . gl-uniform3f)
           (%glUniform3fv . gl-uniform3fv)
           (%glUniform4f .  gl-uniform4f)
           (%glUniform4fv . gl-uniform4fv)
           (%glUniformMatrix3fv . gl-uniform-matrix3fv)
           (%glUniformMatrix4fv . gl-uniform-matrix4fv)
           (%glUniform4f .  gl-uniform4f))

(re-export (%glPointSize . gl-point-size))


;;;
;;; Context Queries
;;;

(re-export (%glGetString . gl-get-string)
           (%glGetIntegerv . gl-get-integer-v))


;;;
;;; Depth Buffer
;;;

(re-export (%glDepthFunc . gl-depth-func)
           (%glDepthMask . gl-depth-mask)
           (%glDepthRange . gl-depth-range))


;;;
;;; Stencil Buffer
;;;

(re-export (%glStencilMask . gl-stencil-mask)
           (%glStencilMaskSeparate . gl-stencil-mask-separate)
           (%glStencilFunc . gl-stencil-func)
           (%glStencilFuncSeparate . gl-stencil-func-separate)
           (%glStencilOp . gl-stencil-op)
           (%glStencilOpSeparate . gl-stencil-op-separate))


;;;
;;; Other State Functions
;;;

(re-export (%glPolygonMode . gl-polygon-mode)
           (%glCullFace . gl-cull-face)
           (%glColorMask . gl-color-mask))


;;;
;;; Errors
;;;

(re-export (%glGetError . gl-get-error))