1 files changed, 228 insertions, 0 deletions

diff --git a/src/core/texture.c b/src/core/texture.c
new file mode 100644
index 0000000..372f9e6
--- /dev/null
+++ b/src/core/texture.c
@@ -0,0 +1,228 @@
+#include "texture.h"
+
+#include <gfx_assert.h>
+
+#include <error.h>
+#include <math/defs.h>
+
+#include <stdbool.h>
+
+bool gfx_init_texture(Texture* texture, const TextureDesc* desc) {
+  assert(texture);
+  assert(desc);
+
+  glGenTextures(1, &texture->id);
+  if (!texture->id) {
+    log_error("glGenTextures() failed");
+    return false;
+  }
+  texture->target = to_GL_dimension(desc->dimension);
+  glBindTexture(texture->target, texture->id);
+
+  // glTexStorageXD
+  const int levels =
+      desc->mipmaps
+          ? max(max(log2(desc->width), log2(desc->height)), log2(desc->depth)) +
+                1
+          : 1;
+  const GLenum internal_format = to_GL_internal_format(desc->format);
+  switch (texture->target) {
+  case GL_TEXTURE_2D:
+  case GL_TEXTURE_CUBE_MAP:
+    glTexStorage2D(
+        texture->target, levels, internal_format, desc->width, desc->height);
+    break;
+  default:
+    FAIL("Unhandled texture dimension");
+    gfx_del_texture(texture);
+    return false;
+  }
+  ASSERT_GL;
+
+  texture->format = to_GL_format(desc->format);
+  texture->type   = to_GL_type(desc->format);
+  texture->width  = desc->width;
+  texture->height = desc->height;
+  gfx_update_texture(texture, &desc->data);
+
+  // gfx_update_texture() unbinds the texture at the end, so re-bind it here.
+  glBindTexture(texture->target, texture->id);
+
+  // Mipmaps.
+  if (desc->mipmaps) {
+    glGenerateMipmap(texture->target);
+    ASSERT_GL;
+  }
+
+  // Texture filtering.
+  const bool linear = desc->filtering == LinearFiltering;
+  GLenum     min    = desc->mipmaps ? (linear ? GL_LINEAR_MIPMAP_LINEAR
+                                              : GL_NEAREST_MIPMAP_NEAREST)
+                                    : (linear ? GL_LINEAR : GL_NEAREST);
+  GLenum     mag    = linear ? GL_LINEAR : GL_NEAREST;
+  glTexParameteri(texture->target, GL_TEXTURE_MIN_FILTER, min);
+  glTexParameteri(texture->target, GL_TEXTURE_MAG_FILTER, mag);
+  ASSERT_GL;
+
+  // Texture wrapping.
+  GLenum wrap = GL_INVALID_ENUM;
+  switch (desc->wrap) {
+  case Repeat:
+    wrap = GL_REPEAT;
+    break;
+  case ClampToEdge:
+    wrap = GL_CLAMP_TO_EDGE;
+    break;
+  }
+  glTexParameteri(texture->target, GL_TEXTURE_WRAP_R, wrap);
+  glTexParameteri(texture->target, GL_TEXTURE_WRAP_S, wrap);
+  glTexParameteri(texture->target, GL_TEXTURE_WRAP_T, wrap);
+  ASSERT_GL;
+
+  glBindTexture(texture->target, 0);
+  return true;
+}
+
+void gfx_del_texture(Texture* texture) {
+  assert(texture);
+
+  if (texture->id) {
+    glDeleteTextures(1, &texture->id);
+    texture->id = 0;
+  }
+}
+
+void gfx_update_texture(Texture* texture, const TextureDataDesc* desc) {
+  assert(texture);
+  assert(desc);
+
+  glBindTexture(texture->target, texture->id);
+
+  // glTexSubImageXD
+  switch (texture->target) {
+  case GL_TEXTURE_2D:
+    if (desc->pixels) {
+      glTexSubImage2D(
+          GL_TEXTURE_2D, /*level=*/0, /*xoffset=*/0,
+          /*yoffset=*/0, texture->width, texture->height, texture->format,
+          texture->type, desc->pixels);
+    }
+    break;
+  case GL_TEXTURE_CUBE_MAP:
+    for (int i = 0; i < 6; ++i) {
+      const void* pixels = *(&desc->cubemap.pixels_pos_x + i);
+      if (pixels) {
+        glTexSubImage2D(
+            GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, /*level=*/0, /*xoffset=*/0,
+            /*yoffset=*/0, texture->width, texture->height, texture->format,
+            texture->type, pixels);
+      }
+    }
+    break;
+  default:
+    FAIL("Unhandled texture dimension");
+    break;
+  }
+  ASSERT_GL;
+
+  glBindTexture(texture->target, 0);
+}
+
+GLenum to_GL_dimension(TextureDimension dim) {
+  switch (dim) {
+  case Texture2D:
+    return GL_TEXTURE_2D;
+  case TextureCubeMap:
+    return GL_TEXTURE_CUBE_MAP;
+  default:
+    FAIL("Unhandled TextureDimension");
+    return GL_INVALID_ENUM;
+  }
+}
+
+GLenum to_GL_internal_format(TextureFormat format) {
+  switch (format) {
+  case TextureDepth:
+    return GL_DEPTH_COMPONENT;
+  case TextureR8:
+    return GL_R8;
+  case TextureRG16:
+    return GL_RG16;
+  case TextureRG16F:
+    return GL_RG16F;
+  case TextureRGB8:
+    return GL_RGB8;
+  case TextureR11G11B10F:
+    return GL_R11F_G11F_B10F;
+  case TextureRGBA8:
+    return GL_RGBA8;
+  case TextureSRGB8:
+    return GL_SRGB8;
+  case TextureSRGBA8:
+    return GL_SRGB8_ALPHA8;
+  default:
+    FAIL("Unhandled TextureFormat");
+    return GL_INVALID_ENUM;
+  }
+}
+
+GLenum to_GL_format(TextureFormat format) {
+  switch (format) {
+  case TextureDepth:
+    return GL_DEPTH_COMPONENT;
+  case TextureR8:
+    return GL_RED;
+  case TextureRG16:
+  case TextureRG16F:
+    return GL_RG;
+  case TextureRGB8:
+  case TextureR11G11B10F:
+  case TextureSRGB8:
+    return GL_RGB;
+  case TextureRGBA8:
+  case TextureSRGBA8:
+    return GL_RGBA;
+  default:
+    FAIL("Unhandled TextureFormat");
+    return GL_INVALID_ENUM;
+  }
+}
+
+GLenum to_GL_type(TextureFormat format) {
+  switch (format) {
+  case TextureDepth:
+  case TextureRG16F:
+  case TextureR11G11B10F:
+    return GL_FLOAT;
+  case TextureR8:
+  case TextureRG16:
+  case TextureRGB8:
+  case TextureRGBA8:
+  case TextureSRGB8:
+  case TextureSRGBA8:
+    return GL_UNSIGNED_BYTE;
+  default:
+    FAIL("Unhandled TextureFormat");
+    return GL_INVALID_ENUM;
+  }
+}
+
+GLenum to_GL_cubemap_face(CubemapFace face) {
+  switch (face) {
+  case CubemapFacePosX:
+    return GL_TEXTURE_CUBE_MAP_POSITIVE_X;
+  case CubemapFaceNegX:
+    return GL_TEXTURE_CUBE_MAP_NEGATIVE_X;
+  case CubemapFacePosY:
+    return GL_TEXTURE_CUBE_MAP_POSITIVE_Y;
+  case CubemapFaceNegY:
+    return GL_TEXTURE_CUBE_MAP_NEGATIVE_Y;
+  case CubemapFacePosZ:
+    return GL_TEXTURE_CUBE_MAP_POSITIVE_Z;
+  case CubemapFaceNegZ:
+    return GL_TEXTURE_CUBE_MAP_NEGATIVE_Z;
+  default:
+    FAIL("Unhandled CubemapFace");
+    return GL_INVALID_ENUM;
+  }
+}