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Diffstat (limited to 'yage/base/spritebatch.cpp')
| -rw-r--r-- | yage/base/spritebatch.cpp | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/yage/base/spritebatch.cpp b/yage/base/spritebatch.cpp new file mode 100644 index 00000000..3aec8153 --- /dev/null +++ b/yage/base/spritebatch.cpp @@ -0,0 +1,193 @@ +/* ---------------------------------------------------------------------------- + * spritebatch.cpp + * + * Copyright (c) 2017 Yann Herklotz Grave <ymherklotz@gmail.com> -- MIT License + * See file LICENSE for more details + * ---------------------------------------------------------------------------- + */ + +#include <yage/base/spritebatch.h> + +#include <algorithm> +#include <stdexcept> + +namespace yage +{ + +const int SpriteBatch::NUM_VERTICES; + +Glyph::Glyph(GLuint texture, float depth, const Vertex &top_left, + const Vertex &top_right, const Vertex &bottom_right, + const Vertex &bottom_left) + : texture_(texture), depth_(depth), top_left_(top_left), + top_right_(top_right), bottom_right_(bottom_right), + bottom_left_(bottom_left) +{ +} + +RenderBatch::RenderBatch(GLint offset, GLsizei num_vertices, GLuint texture) + : num_vertices_(num_vertices), offset_(offset), texture_(texture) +{ +} + +SpriteBatch::SpriteBatch() = default; + +SpriteBatch::~SpriteBatch() +{ + if (vao_ != 0) { + glDeleteVertexArrays(1, &vao_); + } + + if (vbo_ != 0) { + glDeleteVertexArrays(1, &vbo_); + } +} + +void SpriteBatch::init() +{ + createVertexArray(); +} + +void SpriteBatch::begin() +{ + glyphs_.clear(); + glyph_ptrs_.clear(); + render_batches_.clear(); +} + +void SpriteBatch::end() +{ + sortGlyphs(); + createRenderBatches(); +} + +void SpriteBatch::draw(const glm::vec4 &destination_rect, + const glm::vec4 &uv_rect, GLuint texture, + const Color &color, float depth) +{ + Vertex top_left, top_right, bottom_right, bottom_left; + + top_left.color = color; + top_left.setPosition(destination_rect.x, + destination_rect.y + destination_rect.w); + top_left.setUv(uv_rect.x, uv_rect.y + uv_rect.w); + + top_right.color = color; + top_right.setPosition(destination_rect.x + destination_rect.z, + destination_rect.y + destination_rect.w); + top_right.setUv(uv_rect.x + uv_rect.z, uv_rect.y + uv_rect.w); + + bottom_right.color = color; + bottom_right.setPosition(destination_rect.x + destination_rect.z, + destination_rect.y); + bottom_right.setUv(uv_rect.x + uv_rect.z, uv_rect.y); + + bottom_left.color = color; + bottom_left.setPosition(destination_rect.x, destination_rect.y); + bottom_left.setUv(uv_rect.x, uv_rect.y); + + // deal with fragmenting by creating vector of pointers + glyphs_.emplace_back(texture, depth, top_left, top_right, bottom_right, + bottom_left); + glyph_ptrs_.push_back(&glyphs_.back()); +} + +void SpriteBatch::render() +{ + glBindVertexArray(vao_); + for (auto &&batch : render_batches_) { + glBindTexture(GL_TEXTURE_2D, batch.texture()); + glDrawArrays(GL_TRIANGLES, batch.offset(), batch.num_vertices()); + } + glBindVertexArray(0); +} + +void SpriteBatch::createVertexArray() +{ + if (vao_ == 0) { + glGenVertexArrays(1, &vao_); + if (vao_ == 0) { + throw std::runtime_error("glGenVertexArrays failed"); + } + } + // bind vertex array object + glBindVertexArray(vao_); + + if (vbo_ == 0) { + glGenBuffers(1, &vbo_); + if (vbo_ == 0) { + throw std::runtime_error("glGenBuffers failed"); + } + } + // bind vertex buffer object + glBindBuffer(GL_ARRAY_BUFFER, vbo_); + + // enable vertex attribute arrays + glEnableVertexAttribArray(0); + glEnableVertexAttribArray(1); + glEnableVertexAttribArray(2); + + // set the vertex attribute pointers + glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), + (void *)offsetof(Vertex, position)); + glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex), + (void *)offsetof(Vertex, color)); + glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), + (void *)offsetof(Vertex, uv)); + glDrawArrays(GL_TRIANGLES, 0, 6); + + // unbind vertex array object + glBindVertexArray(0); +} + +void SpriteBatch::createRenderBatches() +{ + std::vector<Vertex> vertices; + if (glyph_ptrs_.empty()) { + return; + } + + render_batches_.reserve(glyph_ptrs_.size() * NUM_VERTICES); + + for (int i = 0; i < (int)glyph_ptrs_.size(); ++i) { + if (i == 0 || (i > 0 && (glyph_ptrs_[i]->texture() != + glyph_ptrs_[i - 1]->texture()))) { + render_batches_.emplace_back(i * NUM_VERTICES, NUM_VERTICES, + glyph_ptrs_[i]->texture()); + } else { + render_batches_.back().num_vertices_ += NUM_VERTICES; + } + + vertices.push_back(glyph_ptrs_[i]->bottom_left()); + vertices.push_back(glyph_ptrs_[i]->top_left()); + vertices.push_back(glyph_ptrs_[i]->top_right()); + vertices.push_back(glyph_ptrs_[i]->bottom_left()); + vertices.push_back(glyph_ptrs_[i]->bottom_right()); + vertices.push_back(glyph_ptrs_[i]->top_right()); + + // bind vbo + glBindBuffer(GL_ARRAY_BUFFER, vbo_); + // orphan the buffer + glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), nullptr, + GL_DYNAMIC_DRAW); + // upload the data + glBufferSubData(GL_ARRAY_BUFFER, 0, vertices.size() * sizeof(Vertex), + vertices.data()); + // unbind buffer + glBindBuffer(GL_ARRAY_BUFFER, 0); + } +} + +void SpriteBatch::sortGlyphs() +{ + // sort using introsort or quicksort + std::sort(glyph_ptrs_.begin(), glyph_ptrs_.end(), + [](Glyph *a, Glyph *b) -> bool { + if (a->depth() == b->depth()) { + return a->texture() < b->texture(); + } + return a->depth() < b->depth(); + }); +} + +} // namespace yage |